[PATCH 0/4] fix preemption handling for XENMEM_add_to_physmap_range{, _range}

[PATCH 0/4] fix preemption handling for XENMEM_add_to_physmap_range{, _range}

[Jan Beulich]

The hypervisor isn't supposed to use the input structures for
storing continuation information - only fields explicitly used as
hypercall outputs should ever be updated.

Obviously this implies an ABI change, but since the previous
behavior was not intended to be that way I don't think we should
stick to the old behavior.

There's one caveat though - with the previous model, the caller
could - upon failure - use the updated structure to find out how
by progress was made. However, that wasn't intended afaict,
largely supported by this information depending on hypervisor
internals (i.e. the caller would have to know the order of request 
processing and the meaning of the respective size fields, which
aren't simply saying "this much was processed").

Consequently, as a follow-up we may want to consider making
explicit (and straight forward) this progress indication on error.

1: move XENMEM_add_to_physmap handling framework to common code
2: fix XENMEM_add_to_physmap preemption handling
3: move XENMEM_add_to_physmap_range handling framework to common code
4: fix XENMEM_add_to_physmap_range preemption handling

Signed-off-by: Jan Beulich <jbeulich@suse.com>

[PATCH 1/4] move XENMEM_add_to_physmap handling framework to common code

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 14198 bytes --]

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
supported through XENMEM_add_to_physmap_range is being dropped as being
pointless.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -968,7 +968,7 @@ void share_xen_page_with_privileged_gues
     share_xen_page_with_guest(page, dom_xen, readonly);
 }
 
-static int xenmem_add_to_physmap_one(
+int xenmem_add_to_physmap_one(
     struct domain *d,
     uint16_t space,
     domid_t foreign_domid,
@@ -1118,37 +1118,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        /* Foreign mapping is only supported by add_to_physmap_range */
-        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatp.space, DOMID_INVALID,
-                                       xatp.idx, xatp.gpfn);
-
-        rcu_unlock_domain(d);
-
-        return rc;
-    }
-
     case XENMEM_add_to_physmap_range:
     {
         struct xen_add_to_physmap_range xatpr;
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4520,20 +4520,23 @@ static int handle_iomem_range(unsigned l
     return 0;
 }
 
-static int xenmem_add_to_physmap_once(
+int xenmem_add_to_physmap_one(
     struct domain *d,
-    const struct xen_add_to_physmap *xatp)
+    uint16_t space,
+    domid_t foreign_domid,
+    unsigned long idx,
+    xen_pfn_t gpfn)
 {
     struct page_info *page = NULL;
     unsigned long gfn = 0; /* gcc ... */
-    unsigned long prev_mfn, mfn = 0, gpfn, idx;
+    unsigned long prev_mfn, mfn = 0, old_gpfn;
     int rc;
     p2m_type_t p2mt;
 
-    switch ( xatp->space )
+    switch ( space )
     {
         case XENMAPSPACE_shared_info:
-            if ( xatp->idx == 0 )
+            if ( idx == 0 )
                 mfn = virt_to_mfn(d->shared_info);
             break;
         case XENMAPSPACE_grant_table:
@@ -4542,9 +4545,8 @@ static int xenmem_add_to_physmap_once(
             if ( d->grant_table->gt_version == 0 )
                 d->grant_table->gt_version = 1;
 
-            idx = xatp->idx;
             if ( d->grant_table->gt_version == 2 &&
-                 (xatp->idx & XENMAPIDX_grant_table_status) )
+                 (idx & XENMAPIDX_grant_table_status) )
             {
                 idx &= ~XENMAPIDX_grant_table_status;
                 if ( idx < nr_status_frames(d->grant_table) )
@@ -4566,9 +4568,9 @@ static int xenmem_add_to_physmap_once(
         case XENMAPSPACE_gmfn:
         {
             p2m_type_t p2mt;
-            gfn = xatp->idx;
 
-            idx = mfn_x(get_gfn_unshare(d, xatp->idx, &p2mt));
+            gfn = idx;
+            idx = mfn_x(get_gfn_unshare(d, idx, &p2mt));
             /* If the page is still shared, exit early */
             if ( p2m_is_shared(p2mt) )
             {
@@ -4589,41 +4591,38 @@ static int xenmem_add_to_physmap_once(
     {
         if ( page )
             put_page(page);
-        if ( xatp->space == XENMAPSPACE_gmfn ||
-             xatp->space == XENMAPSPACE_gmfn_range )
+        if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
             put_gfn(d, gfn);
         return -EINVAL;
     }
 
     /* Remove previously mapped page if it was present. */
-    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
+    prev_mfn = mfn_x(get_gfn(d, gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
     {
         if ( is_xen_heap_mfn(prev_mfn) )
             /* Xen heap frames are simply unhooked from this phys slot. */
-            guest_physmap_remove_page(d, xatp->gpfn, prev_mfn, PAGE_ORDER_4K);
+            guest_physmap_remove_page(d, gpfn, prev_mfn, PAGE_ORDER_4K);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */
-            guest_remove_page(d, xatp->gpfn);
+            guest_remove_page(d, gpfn);
     }
     /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */
-    put_gfn(d, xatp->gpfn);
+    put_gfn(d, gpfn);
 
     /* Unmap from old location, if any. */
-    gpfn = get_gpfn_from_mfn(mfn);
-    ASSERT( gpfn != SHARED_M2P_ENTRY );
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
-        ASSERT( gpfn == gfn );
-    if ( gpfn != INVALID_M2P_ENTRY )
-        guest_physmap_remove_page(d, gpfn, mfn, PAGE_ORDER_4K);
+    old_gpfn = get_gpfn_from_mfn(mfn);
+    ASSERT( old_gpfn != SHARED_M2P_ENTRY );
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
+        ASSERT( old_gpfn == gfn );
+    if ( old_gpfn != INVALID_M2P_ENTRY )
+        guest_physmap_remove_page(d, old_gpfn, mfn, PAGE_ORDER_4K);
 
     /* Map at new location. */
-    rc = guest_physmap_add_page(d, xatp->gpfn, mfn, PAGE_ORDER_4K);
+    rc = guest_physmap_add_page(d, gpfn, mfn, PAGE_ORDER_4K);
 
     /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
         put_gfn(d, gfn);
 
     if ( page )
@@ -4632,90 +4631,12 @@ static int xenmem_add_to_physmap_once(
     return rc;
 }
 
-static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
-{
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
-
-    if ( xatp->space == XENMAPSPACE_gmfn_range )
-    {
-        if ( need_iommu(d) )
-            this_cpu(iommu_dont_flush_iotlb) = 1;
-
-        start_xatp = *xatp;
-        while ( xatp->size > 0 )
-        {
-            rc = xenmem_add_to_physmap_once(d, xatp);
-            if ( rc < 0 )
-                break;
-
-            xatp->idx++;
-            xatp->gpfn++;
-            xatp->size--;
-
-            /* Check for continuation if it's not the last interation */
-            if ( xatp->size > 0 && hypercall_preempt_check() )
-            {
-                rc = -EAGAIN;
-                break;
-            }
-        }
-
-        if ( need_iommu(d) )
-        {
-            this_cpu(iommu_dont_flush_iotlb) = 0;
-            iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-            iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
-        }
-
-        return rc;
-    }
-
-    return xenmem_add_to_physmap_once(d, xatp);
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     int rc;
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
-        {
-            rcu_unlock_domain(d);
-            return -EPERM;
-        }
-
-        rc = xenmem_add_to_physmap(d, &xatp);
-
-        rcu_unlock_domain(d);
-
-        if ( xatp.space == XENMAPSPACE_gmfn_range )
-        {
-            if ( rc && __copy_to_guest(arg, &xatp, 1) )
-                rc = -EFAULT;
-
-            if ( rc == -EAGAIN )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-        }
-
-        return rc;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct xen_foreign_memory_map fmap;
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -55,34 +55,6 @@ int compat_arch_memory_op(int op, XEN_GU
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct compat_add_to_physmap cmp;
-        struct xen_add_to_physmap *nat = COMPAT_ARG_XLAT_VIRT_BASE;
-
-        if ( copy_from_guest(&cmp, arg, 1) )
-            return -EFAULT;
-
-        XLAT_add_to_physmap(nat, &cmp);
-        rc = arch_memory_op(op, guest_handle_from_ptr(nat, void));
-
-        if ( !rc || cmp.space != XENMAPSPACE_gmfn_range )
-            break;
-
-        XLAT_add_to_physmap(&cmp, nat);
-        if ( __copy_to_guest(arg, &cmp, 1) )
-        {
-            if ( rc == __HYPERVISOR_memory_op )
-                hypercall_cancel_continuation();
-            return -EFAULT;
-        }
-
-        if ( rc == __HYPERVISOR_memory_op )
-            hypercall_xlat_continuation(NULL, 0x2, nat, arg);
-
-        break;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct compat_foreign_memory_map cmp;
--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -26,11 +26,13 @@ int compat_memory_op(unsigned int cmd, X
             XEN_GUEST_HANDLE_PARAM(void) hnd;
             struct xen_memory_reservation *rsrv;
             struct xen_memory_exchange *xchg;
+            struct xen_add_to_physmap *atp;
             struct xen_remove_from_physmap *xrfp;
         } nat;
         union {
             struct compat_memory_reservation rsrv;
             struct compat_memory_exchange xchg;
+            struct compat_add_to_physmap atp;
         } cmp;
 
         set_xen_guest_handle(nat.hnd, COMPAT_ARG_XLAT_VIRT_BASE);
@@ -187,6 +189,14 @@ int compat_memory_op(unsigned int cmd, X
             nat.hnd = compat;
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( copy_from_guest(&cmp.atp, compat, 1) )
+                return -EFAULT;
+
+            XLAT_add_to_physmap(nat.atp, &cmp.atp);
+
+            break;
+
         case XENMEM_remove_from_physmap:
         {
             struct compat_remove_from_physmap cmp;
@@ -315,6 +325,16 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_remove_from_physmap:
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
+                break;
+
+            XLAT_add_to_physmap(&cmp.atp, nat.atp);
+            if ( __copy_to_guest(compat, &cmp.atp, 1) )
+                rc = -EFAULT;
+
+            break;
+
         default:
             domain_crash(current->domain);
             split = 0;
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -542,6 +542,53 @@ static long memory_exchange(XEN_GUEST_HA
     return rc;
 }
 
+static int xenmem_add_to_physmap(struct domain *d,
+                                 struct xen_add_to_physmap *xatp)
+{
+    struct xen_add_to_physmap start_xatp;
+    int rc = 0;
+
+    if ( xatp->space != XENMAPSPACE_gmfn_range )
+        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                         xatp->idx, xatp->gpfn);
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+        this_cpu(iommu_dont_flush_iotlb) = 1;
+#endif
+
+    start_xatp = *xatp;
+    while ( xatp->size > 0 )
+    {
+        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                       xatp->idx, xatp->gpfn);
+        if ( rc < 0 )
+            break;
+
+        xatp->idx++;
+        xatp->gpfn++;
+        xatp->size--;
+
+        /* Check for continuation if it's not the last interation. */
+        if ( xatp->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            break;
+        }
+    }
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+    {
+        this_cpu(iommu_dont_flush_iotlb) = 0;
+        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+    }
+#endif
+
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -673,6 +720,40 @@ long do_memory_op(unsigned long cmd, XEN
 
         break;
 
+    case XENMEM_add_to_physmap:
+    {
+        struct xen_add_to_physmap xatp;
+
+        if ( copy_from_guest(&xatp, arg, 1) )
+            return -EFAULT;
+
+        d = rcu_lock_domain_by_any_id(xatp.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap(d, &xatp);
+
+        rcu_unlock_domain(d);
+
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatp, 1) )
+                rc = hypercall_create_continuation(
+                        __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -356,6 +356,10 @@ static inline unsigned int get_order_fro
 
 void scrub_one_page(struct page_info *);
 
+int xenmem_add_to_physmap_one(struct domain *d, uint16_t space,
+                              domid_t foreign_domid,
+                              unsigned long idx, xen_pfn_t gpfn);
+
 /* Returns 1 on success, 0 on error, negative if the ring
  * for event propagation is full in the presence of paging */
 int guest_remove_page(struct domain *d, unsigned long gmfn);



[-- Attachment #2: xatp-common.patch --]
[-- Type: text/plain, Size: 14258 bytes --]

move XENMEM_add_to_physmap handling framework to common code

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
supported through XENMEM_add_to_physmap_range is being dropped as being
pointless.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -968,7 +968,7 @@ void share_xen_page_with_privileged_gues
     share_xen_page_with_guest(page, dom_xen, readonly);
 }
 
-static int xenmem_add_to_physmap_one(
+int xenmem_add_to_physmap_one(
     struct domain *d,
     uint16_t space,
     domid_t foreign_domid,
@@ -1118,37 +1118,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        /* Foreign mapping is only supported by add_to_physmap_range */
-        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatp.space, DOMID_INVALID,
-                                       xatp.idx, xatp.gpfn);
-
-        rcu_unlock_domain(d);
-
-        return rc;
-    }
-
     case XENMEM_add_to_physmap_range:
     {
         struct xen_add_to_physmap_range xatpr;
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4520,20 +4520,23 @@ static int handle_iomem_range(unsigned l
     return 0;
 }
 
-static int xenmem_add_to_physmap_once(
+int xenmem_add_to_physmap_one(
     struct domain *d,
-    const struct xen_add_to_physmap *xatp)
+    uint16_t space,
+    domid_t foreign_domid,
+    unsigned long idx,
+    xen_pfn_t gpfn)
 {
     struct page_info *page = NULL;
     unsigned long gfn = 0; /* gcc ... */
-    unsigned long prev_mfn, mfn = 0, gpfn, idx;
+    unsigned long prev_mfn, mfn = 0, old_gpfn;
     int rc;
     p2m_type_t p2mt;
 
-    switch ( xatp->space )
+    switch ( space )
     {
         case XENMAPSPACE_shared_info:
-            if ( xatp->idx == 0 )
+            if ( idx == 0 )
                 mfn = virt_to_mfn(d->shared_info);
             break;
         case XENMAPSPACE_grant_table:
@@ -4542,9 +4545,8 @@ static int xenmem_add_to_physmap_once(
             if ( d->grant_table->gt_version == 0 )
                 d->grant_table->gt_version = 1;
 
-            idx = xatp->idx;
             if ( d->grant_table->gt_version == 2 &&
-                 (xatp->idx & XENMAPIDX_grant_table_status) )
+                 (idx & XENMAPIDX_grant_table_status) )
             {
                 idx &= ~XENMAPIDX_grant_table_status;
                 if ( idx < nr_status_frames(d->grant_table) )
@@ -4566,9 +4568,9 @@ static int xenmem_add_to_physmap_once(
         case XENMAPSPACE_gmfn:
         {
             p2m_type_t p2mt;
-            gfn = xatp->idx;
 
-            idx = mfn_x(get_gfn_unshare(d, xatp->idx, &p2mt));
+            gfn = idx;
+            idx = mfn_x(get_gfn_unshare(d, idx, &p2mt));
             /* If the page is still shared, exit early */
             if ( p2m_is_shared(p2mt) )
             {
@@ -4589,41 +4591,38 @@ static int xenmem_add_to_physmap_once(
     {
         if ( page )
             put_page(page);
-        if ( xatp->space == XENMAPSPACE_gmfn ||
-             xatp->space == XENMAPSPACE_gmfn_range )
+        if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
             put_gfn(d, gfn);
         return -EINVAL;
     }
 
     /* Remove previously mapped page if it was present. */
-    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
+    prev_mfn = mfn_x(get_gfn(d, gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
     {
         if ( is_xen_heap_mfn(prev_mfn) )
             /* Xen heap frames are simply unhooked from this phys slot. */
-            guest_physmap_remove_page(d, xatp->gpfn, prev_mfn, PAGE_ORDER_4K);
+            guest_physmap_remove_page(d, gpfn, prev_mfn, PAGE_ORDER_4K);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */
-            guest_remove_page(d, xatp->gpfn);
+            guest_remove_page(d, gpfn);
     }
     /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */
-    put_gfn(d, xatp->gpfn);
+    put_gfn(d, gpfn);
 
     /* Unmap from old location, if any. */
-    gpfn = get_gpfn_from_mfn(mfn);
-    ASSERT( gpfn != SHARED_M2P_ENTRY );
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
-        ASSERT( gpfn == gfn );
-    if ( gpfn != INVALID_M2P_ENTRY )
-        guest_physmap_remove_page(d, gpfn, mfn, PAGE_ORDER_4K);
+    old_gpfn = get_gpfn_from_mfn(mfn);
+    ASSERT( old_gpfn != SHARED_M2P_ENTRY );
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
+        ASSERT( old_gpfn == gfn );
+    if ( old_gpfn != INVALID_M2P_ENTRY )
+        guest_physmap_remove_page(d, old_gpfn, mfn, PAGE_ORDER_4K);
 
     /* Map at new location. */
-    rc = guest_physmap_add_page(d, xatp->gpfn, mfn, PAGE_ORDER_4K);
+    rc = guest_physmap_add_page(d, gpfn, mfn, PAGE_ORDER_4K);
 
     /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
         put_gfn(d, gfn);
 
     if ( page )
@@ -4632,90 +4631,12 @@ static int xenmem_add_to_physmap_once(
     return rc;
 }
 
-static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
-{
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
-
-    if ( xatp->space == XENMAPSPACE_gmfn_range )
-    {
-        if ( need_iommu(d) )
-            this_cpu(iommu_dont_flush_iotlb) = 1;
-
-        start_xatp = *xatp;
-        while ( xatp->size > 0 )
-        {
-            rc = xenmem_add_to_physmap_once(d, xatp);
-            if ( rc < 0 )
-                break;
-
-            xatp->idx++;
-            xatp->gpfn++;
-            xatp->size--;
-
-            /* Check for continuation if it's not the last interation */
-            if ( xatp->size > 0 && hypercall_preempt_check() )
-            {
-                rc = -EAGAIN;
-                break;
-            }
-        }
-
-        if ( need_iommu(d) )
-        {
-            this_cpu(iommu_dont_flush_iotlb) = 0;
-            iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-            iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
-        }
-
-        return rc;
-    }
-
-    return xenmem_add_to_physmap_once(d, xatp);
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     int rc;
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
-        {
-            rcu_unlock_domain(d);
-            return -EPERM;
-        }
-
-        rc = xenmem_add_to_physmap(d, &xatp);
-
-        rcu_unlock_domain(d);
-
-        if ( xatp.space == XENMAPSPACE_gmfn_range )
-        {
-            if ( rc && __copy_to_guest(arg, &xatp, 1) )
-                rc = -EFAULT;
-
-            if ( rc == -EAGAIN )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-        }
-
-        return rc;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct xen_foreign_memory_map fmap;
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -55,34 +55,6 @@ int compat_arch_memory_op(int op, XEN_GU
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct compat_add_to_physmap cmp;
-        struct xen_add_to_physmap *nat = COMPAT_ARG_XLAT_VIRT_BASE;
-
-        if ( copy_from_guest(&cmp, arg, 1) )
-            return -EFAULT;
-
-        XLAT_add_to_physmap(nat, &cmp);
-        rc = arch_memory_op(op, guest_handle_from_ptr(nat, void));
-
-        if ( !rc || cmp.space != XENMAPSPACE_gmfn_range )
-            break;
-
-        XLAT_add_to_physmap(&cmp, nat);
-        if ( __copy_to_guest(arg, &cmp, 1) )
-        {
-            if ( rc == __HYPERVISOR_memory_op )
-                hypercall_cancel_continuation();
-            return -EFAULT;
-        }
-
-        if ( rc == __HYPERVISOR_memory_op )
-            hypercall_xlat_continuation(NULL, 0x2, nat, arg);
-
-        break;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct compat_foreign_memory_map cmp;
--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -26,11 +26,13 @@ int compat_memory_op(unsigned int cmd, X
             XEN_GUEST_HANDLE_PARAM(void) hnd;
             struct xen_memory_reservation *rsrv;
             struct xen_memory_exchange *xchg;
+            struct xen_add_to_physmap *atp;
             struct xen_remove_from_physmap *xrfp;
         } nat;
         union {
             struct compat_memory_reservation rsrv;
             struct compat_memory_exchange xchg;
+            struct compat_add_to_physmap atp;
         } cmp;
 
         set_xen_guest_handle(nat.hnd, COMPAT_ARG_XLAT_VIRT_BASE);
@@ -187,6 +189,14 @@ int compat_memory_op(unsigned int cmd, X
             nat.hnd = compat;
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( copy_from_guest(&cmp.atp, compat, 1) )
+                return -EFAULT;
+
+            XLAT_add_to_physmap(nat.atp, &cmp.atp);
+
+            break;
+
         case XENMEM_remove_from_physmap:
         {
             struct compat_remove_from_physmap cmp;
@@ -315,6 +325,16 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_remove_from_physmap:
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
+                break;
+
+            XLAT_add_to_physmap(&cmp.atp, nat.atp);
+            if ( __copy_to_guest(compat, &cmp.atp, 1) )
+                rc = -EFAULT;
+
+            break;
+
         default:
             domain_crash(current->domain);
             split = 0;
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -542,6 +542,53 @@ static long memory_exchange(XEN_GUEST_HA
     return rc;
 }
 
+static int xenmem_add_to_physmap(struct domain *d,
+                                 struct xen_add_to_physmap *xatp)
+{
+    struct xen_add_to_physmap start_xatp;
+    int rc = 0;
+
+    if ( xatp->space != XENMAPSPACE_gmfn_range )
+        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                         xatp->idx, xatp->gpfn);
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+        this_cpu(iommu_dont_flush_iotlb) = 1;
+#endif
+
+    start_xatp = *xatp;
+    while ( xatp->size > 0 )
+    {
+        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                       xatp->idx, xatp->gpfn);
+        if ( rc < 0 )
+            break;
+
+        xatp->idx++;
+        xatp->gpfn++;
+        xatp->size--;
+
+        /* Check for continuation if it's not the last interation. */
+        if ( xatp->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            break;
+        }
+    }
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+    {
+        this_cpu(iommu_dont_flush_iotlb) = 0;
+        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+    }
+#endif
+
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -673,6 +720,40 @@ long do_memory_op(unsigned long cmd, XEN
 
         break;
 
+    case XENMEM_add_to_physmap:
+    {
+        struct xen_add_to_physmap xatp;
+
+        if ( copy_from_guest(&xatp, arg, 1) )
+            return -EFAULT;
+
+        d = rcu_lock_domain_by_any_id(xatp.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap(d, &xatp);
+
+        rcu_unlock_domain(d);
+
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatp, 1) )
+                rc = hypercall_create_continuation(
+                        __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -356,6 +356,10 @@ static inline unsigned int get_order_fro
 
 void scrub_one_page(struct page_info *);
 
+int xenmem_add_to_physmap_one(struct domain *d, uint16_t space,
+                              domid_t foreign_domid,
+                              unsigned long idx, xen_pfn_t gpfn);
+
 /* Returns 1 on success, 0 on error, negative if the ring
  * for event propagation is full in the presence of paging */
 int guest_remove_page(struct domain *d, unsigned long gmfn);

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

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Re: [PATCH 1/4] move XENMEM_add_to_physmap handling framework to common code

[Ian Campbell]

On Wed, 2013-12-18 at 14:34 +0000, Jan Beulich wrote:
> There's really nothing really architecture specific here; the
> architecture specific handling is limited to
> xenmem_add_to_physmap_one().
> 
> Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
> supported through XENMEM_add_to_physmap_range is being dropped as being
> pointless.

It's not pointless, dropping this restriction turns a comprehensible
EINVAL result into an incorrect ESRCH result. Which is incorrect because
no domain was specified so how can it not exist.

I'd also rather avoid introducing unnecessary/legacy hypercalls to ARM
if possible.

> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -968,7 +968,7 @@ void share_xen_page_with_privileged_gues
>      share_xen_page_with_guest(page, dom_xen, readonly);
>  }
>  
> -static int xenmem_add_to_physmap_one(
> +int xenmem_add_to_physmap_one(
>      struct domain *d,
>      uint16_t space,
>      domid_t foreign_domid,
> @@ -1118,37 +1118,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
>  
>      switch ( op )
>      {
> -    case XENMEM_add_to_physmap:
> -    {
> -        struct xen_add_to_physmap xatp;
> -        struct domain *d;
> -
> -        if ( copy_from_guest(&xatp, arg, 1) )
> -            return -EFAULT;
> -
> -        /* Foreign mapping is only supported by add_to_physmap_range */
> -        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
> -            return -EINVAL;
> -
> -        d = rcu_lock_domain_by_any_id(xatp.domid);
> -        if ( d == NULL )
> -            return -ESRCH;
> -
> -        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
> -        if ( rc )
> -        {
> -            rcu_unlock_domain(d);
> -            return rc;
> -        }
> -
> -        rc = xenmem_add_to_physmap_one(d, xatp.space, DOMID_INVALID,
> -                                       xatp.idx, xatp.gpfn);
> -
> -        rcu_unlock_domain(d);
> -
> -        return rc;
> -    }
> -
>      case XENMEM_add_to_physmap_range:
>      {
>          struct xen_add_to_physmap_range xatpr;
> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -542,6 +542,53 @@ static long memory_exchange(XEN_GUEST_HA
>      return rc;
>  }
>  
> +static int xenmem_add_to_physmap(struct domain *d,
> +                                 struct xen_add_to_physmap *xatp)
> +{
> +    struct xen_add_to_physmap start_xatp;
> +    int rc = 0;
> +
> +    if ( xatp->space != XENMAPSPACE_gmfn_range )
> +        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
> +                                         xatp->idx, xatp->gpfn);
> +
> +#ifdef HAS_PASSTHROUGH
> +    if ( need_iommu(d) )
> +        this_cpu(iommu_dont_flush_iotlb) = 1;
> +#endif
> +
> +    start_xatp = *xatp;
> +    while ( xatp->size > 0 )
> +    {
> +        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
> +                                       xatp->idx, xatp->gpfn);

ARM's xenmem_add_to_physmap_one does not support XENMAPSPACE_gmfn_range,
so it will return ENOSYS and fail out. I suppose that is ok. But it
makes the bulk of this function pointless. 

How about pulling the != XENMAPSPACE_gmfn_range check into do_memory_op
either calling xenmem_add_to_phymap_one or a per arch gmfn_range
function?

> +        if ( rc < 0 )
> +            break;
> +
> +        xatp->idx++;
> +        xatp->gpfn++;
> +        xatp->size--;
> +
> +        /* Check for continuation if it's not the last interation. */

That's the second or third time this "interation" typo has got
copied ;-)

> +        if ( xatp->size > 0 && hypercall_preempt_check() )
> +        {
> +            rc = -EAGAIN;
> +            break;
> +        }
> +    }
> +
> +#ifdef HAS_PASSTHROUGH
> +    if ( need_iommu(d) )
> +    {
> +        this_cpu(iommu_dont_flush_iotlb) = 0;
> +        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
> +        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
> +    }
> +#endif
> +
> +    return rc;
> +}
> +
>  long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>  {
>      struct domain *d;
> @@ -673,6 +720,40 @@ long do_memory_op(unsigned long cmd, XEN
>  
>          break;
>  
> +    case XENMEM_add_to_physmap:
> +    {
> +        struct xen_add_to_physmap xatp;
> +
> +        if ( copy_from_guest(&xatp, arg, 1) )
> +            return -EFAULT;
> +
> +        d = rcu_lock_domain_by_any_id(xatp.domid);
> +        if ( d == NULL )
> +            return -ESRCH;
> +
> +        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
> +        if ( rc )
> +        {
> +            rcu_unlock_domain(d);
> +            return rc;
> +        }
> +
> +        rc = xenmem_add_to_physmap(d, &xatp);
> +
> +        rcu_unlock_domain(d);
> +
> +        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
> +        {
> +            if ( !__copy_to_guest(arg, &xatp, 1) )
> +                rc = hypercall_create_continuation(
> +                        __HYPERVISOR_memory_op, "ih", op, arg);
> +            else
> +                rc = -EFAULT;
> +        }
> +
> +        return rc;
> +    }
> +
>      case XENMEM_remove_from_physmap:
>      {
>          struct xen_remove_from_physmap xrfp;

Re: [PATCH 1/4] move XENMEM_add_to_physmap handling framework to common code

[Jan Beulich]

>>> On 18.12.13 at 18:52, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> On Wed, 2013-12-18 at 14:34 +0000, Jan Beulich wrote:
>> There's really nothing really architecture specific here; the
>> architecture specific handling is limited to
>> xenmem_add_to_physmap_one().
>> 
>> Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
>> supported through XENMEM_add_to_physmap_range is being dropped as being
>> pointless.
> 
> It's not pointless, dropping this restriction turns a comprehensible
> EINVAL result into an incorrect ESRCH result. Which is incorrect because
> no domain was specified so how can it not exist.

How can there have been no domain specified for a
XENMAPSPACE_gmfn_foreign? If the field was left uninitialized,
-ESRCH would be as valid as -EINVAL, and I don't think we
specify for any hypercall that between multiple applicable
error code a specific one would be preferred over others.

> I'd also rather avoid introducing unnecessary/legacy hypercalls to ARM
> if possible.

I can understand that, but please also take the perspective that
moving the architecture independent bits out should have been
done much earlier, and (see below) adding a conditional here
doesn't seem too attractive to me.

>> +static int xenmem_add_to_physmap(struct domain *d,
>> +                                 struct xen_add_to_physmap *xatp)
>> +{
>> +    struct xen_add_to_physmap start_xatp;
>> +    int rc = 0;
>> +
>> +    if ( xatp->space != XENMAPSPACE_gmfn_range )
>> +        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
>> +                                         xatp->idx, xatp->gpfn);
>> +
>> +#ifdef HAS_PASSTHROUGH
>> +    if ( need_iommu(d) )
>> +        this_cpu(iommu_dont_flush_iotlb) = 1;
>> +#endif
>> +
>> +    start_xatp = *xatp;
>> +    while ( xatp->size > 0 )
>> +    {
>> +        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
>> +                                       xatp->idx, xatp->gpfn);
> 
> ARM's xenmem_add_to_physmap_one does not support XENMAPSPACE_gmfn_range,
> so it will return ENOSYS and fail out. I suppose that is ok. But it
> makes the bulk of this function pointless. 
> 
> How about pulling the != XENMAPSPACE_gmfn_range check into do_memory_op
> either calling xenmem_add_to_phymap_one or a per arch gmfn_range
> function?

No, I think having just one arch specific function dealing with
everything, and having the common code really take care of
as much as is common is the right thing (and considering the
review by Tim and the ack from Keir, I think others agree).

Which would leave the option of adding a #ifdef CONFIG_ARM
(or #ifndef CONFIG_X86) in the common code - not really nice.

>> +        if ( rc < 0 )
>> +            break;
>> +
>> +        xatp->idx++;
>> +        xatp->gpfn++;
>> +        xatp->size--;
>> +
>> +        /* Check for continuation if it's not the last interation. */
> 
> That's the second or third time this "interation" typo has got
> copied ;-)

Fixed - I didn't look that closely at the comments I was moving
around. Albeit I had noticed and fixed the missing stops...

Jan

Re: [PATCH 1/4] move XENMEM_add_to_physmap handling framework to common code

[Ian Campbell]

On Fri, 2013-12-20 at 07:48 +0000, Jan Beulich wrote:
> >>> On 18.12.13 at 18:52, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> > On Wed, 2013-12-18 at 14:34 +0000, Jan Beulich wrote:
> >> There's really nothing really architecture specific here; the
> >> architecture specific handling is limited to
> >> xenmem_add_to_physmap_one().
> >> 
> >> Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
> >> supported through XENMEM_add_to_physmap_range is being dropped as being
> >> pointless.
> > 
> > It's not pointless, dropping this restriction turns a comprehensible
> > EINVAL result into an incorrect ESRCH result. Which is incorrect because
> > no domain was specified so how can it not exist.
> 
> How can there have been no domain specified for a
> XENMAPSPACE_gmfn_foreign?

The arguments to XENMEM_add_to_physmap have no field which specifies a
foreign domain. (this is one of the reasons we added the _range version
with the field in the first place).

The domid parameter to add_to_physmap one is why hardcoded to
DOMID_INVALID in all the add_to_physmap (!range) cases.

>  If the field was left uninitialized,
> -ESRCH would be as valid as -EINVAL, and I don't think we
> specify for any hypercall that between multiple applicable
> error code a specific one would be preferred over others.

I think given the above -ESRCH is invalid, since there is no field to
have been left uninitialised.

> > I'd also rather avoid introducing unnecessary/legacy hypercalls to ARM
> > if possible.
> 
> I can understand that, but please also take the perspective that
> moving the architecture independent bits out should have been
> done much earlier, and (see below) adding a conditional here
> doesn't seem too attractive to me.

I don't think this should be a per arch conditional, if that's what you
mean, just a blanket if ( ) return ENOSYS.

> >> +static int xenmem_add_to_physmap(struct domain *d,
> >> +                                 struct xen_add_to_physmap *xatp)
> >> +{
> >> +    struct xen_add_to_physmap start_xatp;
> >> +    int rc = 0;
> >> +
> >> +    if ( xatp->space != XENMAPSPACE_gmfn_range )
> >> +        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
> >> +                                         xatp->idx, xatp->gpfn);
> >> +
> >> +#ifdef HAS_PASSTHROUGH
> >> +    if ( need_iommu(d) )
> >> +        this_cpu(iommu_dont_flush_iotlb) = 1;
> >> +#endif
> >> +
> >> +    start_xatp = *xatp;
> >> +    while ( xatp->size > 0 )
> >> +    {
> >> +        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
> >> +                                       xatp->idx, xatp->gpfn);
> > 
> > ARM's xenmem_add_to_physmap_one does not support XENMAPSPACE_gmfn_range,
> > so it will return ENOSYS and fail out. I suppose that is ok. But it
> > makes the bulk of this function pointless. 
> > 
> > How about pulling the != XENMAPSPACE_gmfn_range check into do_memory_op
> > either calling xenmem_add_to_phymap_one or a per arch gmfn_range
> > function?
> 
> No, I think having just one arch specific function dealing with
> everything, and having the common code really take care of
> as much as is common is the right thing (and considering the
> review by Tim and the ack from Keir, I think others agree).
> 
> Which would leave the option of adding a #ifdef CONFIG_ARM
> (or #ifndef CONFIG_X86) in the common code - not really nice.

(note that this is a different case to the above gmfn_range here vs
gmfn_foreign there)

The #ifndef would be the better of those two, since I'd expect no other
port to be added with this legacy interface. Another option would be
HAVE_FOO.

But in any case leaving this is not too harmful since the end result is
correct -ENOSYS anyway.

Ian.

Re: [PATCH 1/4] move XENMEM_add_to_physmap handling framework to common code

[Jan Beulich]

>>> On 20.12.13 at 09:58, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> On Fri, 2013-12-20 at 07:48 +0000, Jan Beulich wrote:
>> >>> On 18.12.13 at 18:52, Ian Campbell <Ian.Campbell@citrix.com> wrote:
>> > On Wed, 2013-12-18 at 14:34 +0000, Jan Beulich wrote:
>> >> There's really nothing really architecture specific here; the
>> >> architecture specific handling is limited to
>> >> xenmem_add_to_physmap_one().
>> >> 
>> >> Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
>> >> supported through XENMEM_add_to_physmap_range is being dropped as being
>> >> pointless.
>> > 
>> > It's not pointless, dropping this restriction turns a comprehensible
>> > EINVAL result into an incorrect ESRCH result. Which is incorrect because
>> > no domain was specified so how can it not exist.
>> 
>> How can there have been no domain specified for a
>> XENMAPSPACE_gmfn_foreign?
> 
> The arguments to XENMEM_add_to_physmap have no field which specifies a
> foreign domain. (this is one of the reasons we added the _range version
> with the field in the first place).
> 
> The domid parameter to add_to_physmap one is why hardcoded to
> DOMID_INVALID in all the add_to_physmap (!range) cases.
> 
>>  If the field was left uninitialized,
>> -ESRCH would be as valid as -EINVAL, and I don't think we
>> specify for any hypercall that between multiple applicable
>> error code a specific one would be preferred over others.
> 
> I think given the above -ESRCH is invalid, since there is no field to
> have been left uninitialised.

Oh, I finally understand. The thing that mainly confused me here
is the wording of the original comment: "Foreign mapping is only
supported by add_to_physmap_range". Whereas it should have
said "Foreign mapping is only possible through
add_to_physmap_range". I'll re-add that with the adjusted
comment.

Will that make the patch acceptable to you?

Jan

Re: [PATCH 1/4] move XENMEM_add_to_physmap handling framework to common code

[Ian Campbell]

On Fri, 2013-12-20 at 09:12 +0000, Jan Beulich wrote:
> >>> On 20.12.13 at 09:58, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> > On Fri, 2013-12-20 at 07:48 +0000, Jan Beulich wrote:
> >> >>> On 18.12.13 at 18:52, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> >> > On Wed, 2013-12-18 at 14:34 +0000, Jan Beulich wrote:
> >> >> There's really nothing really architecture specific here; the
> >> >> architecture specific handling is limited to
> >> >> xenmem_add_to_physmap_one().
> >> >> 
> >> >> Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
> >> >> supported through XENMEM_add_to_physmap_range is being dropped as being
> >> >> pointless.
> >> > 
> >> > It's not pointless, dropping this restriction turns a comprehensible
> >> > EINVAL result into an incorrect ESRCH result. Which is incorrect because
> >> > no domain was specified so how can it not exist.
> >> 
> >> How can there have been no domain specified for a
> >> XENMAPSPACE_gmfn_foreign?
> > 
> > The arguments to XENMEM_add_to_physmap have no field which specifies a
> > foreign domain. (this is one of the reasons we added the _range version
> > with the field in the first place).
> > 
> > The domid parameter to add_to_physmap one is why hardcoded to
> > DOMID_INVALID in all the add_to_physmap (!range) cases.
> > 
> >>  If the field was left uninitialized,
> >> -ESRCH would be as valid as -EINVAL, and I don't think we
> >> specify for any hypercall that between multiple applicable
> >> error code a specific one would be preferred over others.
> > 
> > I think given the above -ESRCH is invalid, since there is no field to
> > have been left uninitialised.
> 
> Oh, I finally understand. The thing that mainly confused me here
> is the wording of the original comment: "Foreign mapping is only
> supported by add_to_physmap_range". Whereas it should have
> said "Foreign mapping is only possible through
> add_to_physmap_range". I'll re-add that with the adjusted
> comment.

Yes, thanks.

> Will that make the patch acceptable to you?

I believe so, yes, I'll look at v3 ASAP.

Ian.

[PATCH 2/4] fix XENMEM_add_to_physmap preemption handling

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 5309 bytes --]

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -190,6 +190,9 @@ int compat_memory_op(unsigned int cmd, X
             break;
 
         case XENMEM_add_to_physmap:
+            BUILD_BUG_ON((typeof(cmp.atp.size))-1 >
+                         (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
             if ( copy_from_guest(&cmp.atp, compat, 1) )
                 return -EFAULT;
 
@@ -322,17 +325,8 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_current_reservation:
         case XENMEM_maximum_reservation:
         case XENMEM_maximum_gpfn:
-        case XENMEM_remove_from_physmap:
-            break;
-
         case XENMEM_add_to_physmap:
-            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
-                break;
-
-            XLAT_add_to_physmap(&cmp.atp, nat.atp);
-            if ( __copy_to_guest(compat, &cmp.atp, 1) )
-                rc = -EFAULT;
-
+        case XENMEM_remove_from_physmap:
             break;
 
         default:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -543,22 +543,32 @@ static long memory_exchange(XEN_GUEST_HA
 }
 
 static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
+                                 struct xen_add_to_physmap *xatp,
+                                 unsigned int start)
 {
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
+    unsigned int done = 0;
+    long rc = 0;
 
     if ( xatp->space != XENMAPSPACE_gmfn_range )
+    {
+        ASSERT(!start);
         return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                          xatp->idx, xatp->gpfn);
+    }
+
+    if ( xatp->size < start )
+        return -EILSEQ;
+
+    xatp->idx += start;
+    xatp->gpfn += start;
+    xatp->size -= start;
 
 #ifdef HAS_PASSTHROUGH
     if ( need_iommu(d) )
         this_cpu(iommu_dont_flush_iotlb) = 1;
 #endif
 
-    start_xatp = *xatp;
-    while ( xatp->size > 0 )
+    while ( xatp->size > done )
     {
         rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                        xatp->idx, xatp->gpfn);
@@ -567,12 +577,11 @@ static int xenmem_add_to_physmap(struct 
 
         xatp->idx++;
         xatp->gpfn++;
-        xatp->size--;
 
         /* Check for continuation if it's not the last interation. */
-        if ( xatp->size > 0 && hypercall_preempt_check() )
+        if ( xatp->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             break;
         }
     }
@@ -581,8 +590,8 @@ static int xenmem_add_to_physmap(struct 
     if ( need_iommu(d) )
     {
         this_cpu(iommu_dont_flush_iotlb) = 0;
-        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, xatp->idx - done, done);
+        iommu_iotlb_flush(d, xatp->gpfn - done, done);
     }
 #endif
 
@@ -594,10 +603,10 @@ long do_memory_op(unsigned long cmd, XEN
     struct domain *d;
     long rc;
     unsigned int address_bits;
-    unsigned long start_extent;
     struct xen_memory_reservation reservation;
     struct memop_args args;
     domid_t domid;
+    unsigned long start_extent = cmd >> MEMOP_EXTENT_SHIFT;
     int op = cmd & MEMOP_CMD_MASK;
 
     switch ( op )
@@ -605,8 +614,6 @@ long do_memory_op(unsigned long cmd, XEN
     case XENMEM_increase_reservation:
     case XENMEM_decrease_reservation:
     case XENMEM_populate_physmap:
-        start_extent = cmd >> MEMOP_EXTENT_SHIFT;
-
         if ( copy_from_guest(&reservation, arg, 1) )
             return start_extent;
 
@@ -724,6 +731,12 @@ long do_memory_op(unsigned long cmd, XEN
     {
         struct xen_add_to_physmap xatp;
 
+        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for faked input. */
+        if ( start_extent != (typeof(xatp.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
@@ -738,18 +751,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap(d, &xatp);
+        rc = xenmem_add_to_physmap(d, &xatp, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatp, 1) )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc > 0 )
+            rc = hypercall_create_continuation(
+                     __HYPERVISOR_memory_op, "lh",
+                     op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }



[-- Attachment #2: xatp-preemption.patch --]
[-- Type: text/plain, Size: 5354 bytes --]

fix XENMEM_add_to_physmap preemption handling

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -190,6 +190,9 @@ int compat_memory_op(unsigned int cmd, X
             break;
 
         case XENMEM_add_to_physmap:
+            BUILD_BUG_ON((typeof(cmp.atp.size))-1 >
+                         (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
             if ( copy_from_guest(&cmp.atp, compat, 1) )
                 return -EFAULT;
 
@@ -322,17 +325,8 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_current_reservation:
         case XENMEM_maximum_reservation:
         case XENMEM_maximum_gpfn:
-        case XENMEM_remove_from_physmap:
-            break;
-
         case XENMEM_add_to_physmap:
-            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
-                break;
-
-            XLAT_add_to_physmap(&cmp.atp, nat.atp);
-            if ( __copy_to_guest(compat, &cmp.atp, 1) )
-                rc = -EFAULT;
-
+        case XENMEM_remove_from_physmap:
             break;
 
         default:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -543,22 +543,32 @@ static long memory_exchange(XEN_GUEST_HA
 }
 
 static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
+                                 struct xen_add_to_physmap *xatp,
+                                 unsigned int start)
 {
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
+    unsigned int done = 0;
+    long rc = 0;
 
     if ( xatp->space != XENMAPSPACE_gmfn_range )
+    {
+        ASSERT(!start);
         return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                          xatp->idx, xatp->gpfn);
+    }
+
+    if ( xatp->size < start )
+        return -EILSEQ;
+
+    xatp->idx += start;
+    xatp->gpfn += start;
+    xatp->size -= start;
 
 #ifdef HAS_PASSTHROUGH
     if ( need_iommu(d) )
         this_cpu(iommu_dont_flush_iotlb) = 1;
 #endif
 
-    start_xatp = *xatp;
-    while ( xatp->size > 0 )
+    while ( xatp->size > done )
     {
         rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                        xatp->idx, xatp->gpfn);
@@ -567,12 +577,11 @@ static int xenmem_add_to_physmap(struct 
 
         xatp->idx++;
         xatp->gpfn++;
-        xatp->size--;
 
         /* Check for continuation if it's not the last interation. */
-        if ( xatp->size > 0 && hypercall_preempt_check() )
+        if ( xatp->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             break;
         }
     }
@@ -581,8 +590,8 @@ static int xenmem_add_to_physmap(struct 
     if ( need_iommu(d) )
     {
         this_cpu(iommu_dont_flush_iotlb) = 0;
-        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, xatp->idx - done, done);
+        iommu_iotlb_flush(d, xatp->gpfn - done, done);
     }
 #endif
 
@@ -594,10 +603,10 @@ long do_memory_op(unsigned long cmd, XEN
     struct domain *d;
     long rc;
     unsigned int address_bits;
-    unsigned long start_extent;
     struct xen_memory_reservation reservation;
     struct memop_args args;
     domid_t domid;
+    unsigned long start_extent = cmd >> MEMOP_EXTENT_SHIFT;
     int op = cmd & MEMOP_CMD_MASK;
 
     switch ( op )
@@ -605,8 +614,6 @@ long do_memory_op(unsigned long cmd, XEN
     case XENMEM_increase_reservation:
     case XENMEM_decrease_reservation:
     case XENMEM_populate_physmap:
-        start_extent = cmd >> MEMOP_EXTENT_SHIFT;
-
         if ( copy_from_guest(&reservation, arg, 1) )
             return start_extent;
 
@@ -724,6 +731,12 @@ long do_memory_op(unsigned long cmd, XEN
     {
         struct xen_add_to_physmap xatp;
 
+        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for faked input. */
+        if ( start_extent != (typeof(xatp.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
@@ -738,18 +751,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap(d, &xatp);
+        rc = xenmem_add_to_physmap(d, &xatp, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatp, 1) )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc > 0 )
+            rc = hypercall_create_continuation(
+                     __HYPERVISOR_memory_op, "lh",
+                     op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
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Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

Re: [PATCH 2/4] fix XENMEM_add_to_physmap preemption handling

[Tim Deegan]

At 14:35 +0000 on 18 Dec (1387373707), Jan Beulich wrote:
> Just like for all other hypercalls we shouldn't be modifying the input
> structure - all of the fields are, even if not explicitly documented,
> just inputs.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

> @@ -543,22 +543,32 @@ static long memory_exchange(XEN_GUEST_HA
>  }
>  
>  static int xenmem_add_to_physmap(struct domain *d,
> -                                 struct xen_add_to_physmap *xatp)
> +                                 struct xen_add_to_physmap *xatp,
> +                                 unsigned int start)
>  {
> -    struct xen_add_to_physmap start_xatp;
> -    int rc = 0;
> +    unsigned int done = 0;
> +    long rc = 0;
>  
>      if ( xatp->space != XENMAPSPACE_gmfn_range )
> +    {
> +        ASSERT(!start);

I don't think you've enforced this in the caller; you only check that
the guest hasn't supplied an over-sized start-extent.  I think it's
fine just to ignore start for singleton operations anyway.

Cheers,

Tim.

Re: [PATCH 2/4] fix XENMEM_add_to_physmap preemption handling

[Jan Beulich]

>>> On 18.12.13 at 16:48, Tim Deegan <tim@xen.org> wrote:
> At 14:35 +0000 on 18 Dec (1387373707), Jan Beulich wrote:
>> Just like for all other hypercalls we shouldn't be modifying the input
>> structure - all of the fields are, even if not explicitly documented,
>> just inputs.
>> 
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
>> @@ -543,22 +543,32 @@ static long memory_exchange(XEN_GUEST_HA
>>  }
>>  
>>  static int xenmem_add_to_physmap(struct domain *d,
>> -                                 struct xen_add_to_physmap *xatp)
>> +                                 struct xen_add_to_physmap *xatp,
>> +                                 unsigned int start)
>>  {
>> -    struct xen_add_to_physmap start_xatp;
>> -    int rc = 0;
>> +    unsigned int done = 0;
>> +    long rc = 0;
>>  
>>      if ( xatp->space != XENMAPSPACE_gmfn_range )
>> +    {
>> +        ASSERT(!start);
> 
> I don't think you've enforced this in the caller; you only check that
> the guest hasn't supplied an over-sized start-extent.  I think it's
> fine just to ignore start for singleton operations anyway.

Right, if at all I should be returning an error here. But that should
perhaps either done uniformly at once for all mem ops, or not at
all.

I'll just drop that change - makes the patch smaller :-)

Jan

Re: [PATCH 2/4] fix XENMEM_add_to_physmap preemption handling

[Tim Deegan]

At 16:03 +0000 on 18 Dec (1387378993), Jan Beulich wrote:
> >>> On 18.12.13 at 16:48, Tim Deegan <tim@xen.org> wrote:
> > At 14:35 +0000 on 18 Dec (1387373707), Jan Beulich wrote:
> >> Just like for all other hypercalls we shouldn't be modifying the input
> >> structure - all of the fields are, even if not explicitly documented,
> >> just inputs.
> >> 
> >> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> > 
> >> @@ -543,22 +543,32 @@ static long memory_exchange(XEN_GUEST_HA
> >>  }
> >>  
> >>  static int xenmem_add_to_physmap(struct domain *d,
> >> -                                 struct xen_add_to_physmap *xatp)
> >> +                                 struct xen_add_to_physmap *xatp,
> >> +                                 unsigned int start)
> >>  {
> >> -    struct xen_add_to_physmap start_xatp;
> >> -    int rc = 0;
> >> +    unsigned int done = 0;
> >> +    long rc = 0;
> >>  
> >>      if ( xatp->space != XENMAPSPACE_gmfn_range )
> >> +    {
> >> +        ASSERT(!start);
> > 
> > I don't think you've enforced this in the caller; you only check that
> > the guest hasn't supplied an over-sized start-extent.  I think it's
> > fine just to ignore start for singleton operations anyway.
> 
> Right, if at all I should be returning an error here. But that should
> perhaps either done uniformly at once for all mem ops, or not at
> all.
> 
> I'll just drop that change - makes the patch smaller :-)

Grand so. :)  With that dropped, 1/4 and 2/4 are
Reviewed-by: Tim Deegan <tim@xen.org>

Re: [PATCH 2/4] fix XENMEM_add_to_physmap preemption handling

[Ian Campbell]

On Wed, 2013-12-18 at 14:35 +0000, Jan Beulich wrote:
> J
>          /* Check for continuation if it's not the last interation. */
> -        if ( xatp->size > 0 && hypercall_preempt_check() )
> +        if ( xatp->size > ++done && hypercall_preempt_check() )

Hiding the loop increment inside the preemption checking is a bit subtle
(it took me a while to find it). Can't it go either before or after this
loop? With a suitable +/- 1 to the rc below if necessary.

> @@ -724,6 +731,12 @@ long do_memory_op(unsigned long cmd, XEN
>      {
>          struct xen_add_to_physmap xatp;
>  
> +        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));

What does "typeof(xatp.size)-1" evaluate to? typeof can't return an int,
cant it?

> +
> +        /* Check for faked input. */

Faked as in "malicious" or faked as in "something we made up for
continuation purposes" ?

Re: [PATCH 2/4] fix XENMEM_add_to_physmap preemption handling

[Jan Beulich]

>>> On 18.12.13 at 18:59, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> On Wed, 2013-12-18 at 14:35 +0000, Jan Beulich wrote:
>> J
>>          /* Check for continuation if it's not the last interation. */
>> -        if ( xatp->size > 0 && hypercall_preempt_check() )
>> +        if ( xatp->size > ++done && hypercall_preempt_check() )
> 
> Hiding the loop increment inside the preemption checking is a bit subtle
> (it took me a while to find it). Can't it go either before or after this
> loop? With a suitable +/- 1 to the rc below if necessary.

It could, but I find it quite natural to be together with the check.

>> @@ -724,6 +731,12 @@ long do_memory_op(unsigned long cmd, XEN
>>      {
>>          struct xen_add_to_physmap xatp;
>>  
>> +        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
> 
> What does "typeof(xatp.size)-1" evaluate to? typeof can't return an int,
> cant it?

Properly parenthesized this is ((uint16_t)-1), i.e. 0xffff (typeof()
doesn't produce a value, but a type).

>> +
>> +        /* Check for faked input. */
> 
> Faked as in "malicious" or faked as in "something we made up for
> continuation purposes" ?

As in "malicious" (or buggy), i.e. the caller passing an out of range
"cmd" to HYPERVISOR_memory_op. Do you have any better wording
in mind?

Jan

Re: [PATCH 2/4] fix XENMEM_add_to_physmap preemption handling

[Ian Campbell]

On Fri, 2013-12-20 at 07:52 +0000, Jan Beulich wrote:
> >>> On 18.12.13 at 18:59, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> > On Wed, 2013-12-18 at 14:35 +0000, Jan Beulich wrote:
> >> J
> >>          /* Check for continuation if it's not the last interation. */
> >> -        if ( xatp->size > 0 && hypercall_preempt_check() )
> >> +        if ( xatp->size > ++done && hypercall_preempt_check() )
> > 
> > Hiding the loop increment inside the preemption checking is a bit subtle
> > (it took me a while to find it). Can't it go either before or after this
> > loop? With a suitable +/- 1 to the rc below if necessary.
> 
> It could, but I find it quite natural to be together with the check.

If it were the loop termination check or something then I would agree,
but this is effectively some other arbitrary check within the loop (even
if it does happen to exit, it's not the primary loop termination
condition).

> >> @@ -724,6 +731,12 @@ long do_memory_op(unsigned long cmd, XEN
> >>      {
> >>          struct xen_add_to_physmap xatp;
> >>  
> >> +        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
> > 
> > What does "typeof(xatp.size)-1" evaluate to? typeof can't return an int,
> > cant it?
> 
> Properly parenthesized this is ((uint16_t)-1), i.e. 0xffff 

Ah! Yes, I misread that rather badly.

> (typeof() doesn't produce a value, but a type).

I know, that's why I was so confused when it looked like it was being
treated as a value!

> >> +
> >> +        /* Check for faked input. */
> > 
> > Faked as in "malicious" or faked as in "something we made up for
> > continuation purposes" ?
> 
> As in "malicious" (or buggy), i.e. the caller passing an out of range
> "cmd" to HYPERVISOR_memory_op. Do you have any better wording
> in mind?

"Check for malicious or buggy input" would do the job. (with or without
"or buggy")

Ian.

Re: [PATCH 2/4] fix XENMEM_add_to_physmap preemption handling

[Jan Beulich]

>>> On 20.12.13 at 10:02, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> On Fri, 2013-12-20 at 07:52 +0000, Jan Beulich wrote:
>> >>> On 18.12.13 at 18:59, Ian Campbell <Ian.Campbell@citrix.com> wrote:
>> > On Wed, 2013-12-18 at 14:35 +0000, Jan Beulich wrote:
>> >> +
>> >> +        /* Check for faked input. */
>> > 
>> > Faked as in "malicious" or faked as in "something we made up for
>> > continuation purposes" ?
>> 
>> As in "malicious" (or buggy), i.e. the caller passing an out of range
>> "cmd" to HYPERVISOR_memory_op. Do you have any better wording
>> in mind?
> 
> "Check for malicious or buggy input" would do the job. (with or without
> "or buggy")

Fine with me - changed that way.

Jan

[PATCH 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 6096 bytes --]

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

Note the restriction of XENMAPSPACE_gmfn_range only being supported
through XENMEM_add_to_physmap is being dropped as being pointless.

This further eliminates the erroneous bailing from
xenmem_add_to_physmap_range() if xenmem_add_to_physmap_one() fails.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1056,103 +1056,10 @@ int xenmem_add_to_physmap_one(
     return rc;
 }
 
-static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
-{
-    int rc;
-
-    while ( xatpr->size > 0 )
-    {
-        xen_ulong_t idx;
-        xen_pfn_t gpfn;
-
-        if ( unlikely(copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( unlikely(copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatpr->space,
-                                       xatpr->foreign_domid,
-                                       idx, gpfn);
-
-        if ( unlikely(copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( rc < 0 )
-            goto out;
-
-        guest_handle_add_offset(xatpr->idxs, 1);
-        guest_handle_add_offset(xatpr->gpfns, 1);
-        guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
-
-        /* Check for continuation if it's not the last interation */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
-        {
-            rc = -EAGAIN;
-            goto out;
-        }
-    }
-
-    rc = 0;
-
-out:
-    return rc;
-
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    int rc;
-
     switch ( op )
     {
-    case XENMEM_add_to_physmap_range:
-    {
-        struct xen_add_to_physmap_range xatpr;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatpr, arg, 1) )
-            return -EFAULT;
-
-        /* This mapspace is redundant for this hypercall */
-        if ( xatpr.space == XENMAPSPACE_gmfn_range )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatpr.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
-
-        rcu_unlock_domain(d);
-
-        if ( rc && copy_to_guest(arg, &xatpr, 1) )
-            rc = -EFAULT;
-
-        if ( rc == -EAGAIN )
-            rc = hypercall_create_continuation(
-                __HYPERVISOR_memory_op, "ih", op, arg);
-
-        return rc;
-    }
     /* XXX: memsharing not working yet */
     case XENMEM_get_sharing_shared_pages:
     case XENMEM_get_sharing_freed_pages:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -598,6 +598,57 @@ static int xenmem_add_to_physmap(struct 
     return rc;
 }
 
+static int xenmem_add_to_physmap_range(struct domain *d,
+                                       struct xen_add_to_physmap_range *xatpr)
+{
+    int rc;
+
+    while ( xatpr->size > 0 )
+    {
+        xen_ulong_t idx;
+        xen_pfn_t gpfn;
+
+        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        rc = xenmem_add_to_physmap_one(d, xatpr->space,
+                                       xatpr->foreign_domid,
+                                       idx, gpfn);
+
+        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        guest_handle_add_offset(xatpr->idxs, 1);
+        guest_handle_add_offset(xatpr->gpfns, 1);
+        guest_handle_add_offset(xatpr->errs, 1);
+        xatpr->size--;
+
+        /* Check for continuation if it's not the last interation. */
+        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            goto out;
+        }
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -763,6 +814,44 @@ long do_memory_op(unsigned long cmd, XEN
         return rc;
     }
 
+    case XENMEM_add_to_physmap_range:
+    {
+        struct xen_add_to_physmap_range xatpr;
+        struct domain *d;
+
+        if ( copy_from_guest(&xatpr, arg, 1) ||
+             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
+             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
+             !guest_handle_okay(xatpr.errs, xatpr.size) )
+            return -EFAULT;
+
+        d = rcu_lock_domain_by_any_id(xatpr.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap_range(d, &xatpr);
+
+        rcu_unlock_domain(d);
+
+        if ( rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatpr, 1) )
+                rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;



[-- Attachment #2: xatpr-common.patch --]
[-- Type: text/plain, Size: 6162 bytes --]

move XENMEM_add_to_physmap_range handling framework to common code

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

Note the restriction of XENMAPSPACE_gmfn_range only being supported
through XENMEM_add_to_physmap is being dropped as being pointless.

This further eliminates the erroneous bailing from
xenmem_add_to_physmap_range() if xenmem_add_to_physmap_one() fails.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1056,103 +1056,10 @@ int xenmem_add_to_physmap_one(
     return rc;
 }
 
-static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
-{
-    int rc;
-
-    while ( xatpr->size > 0 )
-    {
-        xen_ulong_t idx;
-        xen_pfn_t gpfn;
-
-        if ( unlikely(copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( unlikely(copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatpr->space,
-                                       xatpr->foreign_domid,
-                                       idx, gpfn);
-
-        if ( unlikely(copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( rc < 0 )
-            goto out;
-
-        guest_handle_add_offset(xatpr->idxs, 1);
-        guest_handle_add_offset(xatpr->gpfns, 1);
-        guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
-
-        /* Check for continuation if it's not the last interation */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
-        {
-            rc = -EAGAIN;
-            goto out;
-        }
-    }
-
-    rc = 0;
-
-out:
-    return rc;
-
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    int rc;
-
     switch ( op )
     {
-    case XENMEM_add_to_physmap_range:
-    {
-        struct xen_add_to_physmap_range xatpr;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatpr, arg, 1) )
-            return -EFAULT;
-
-        /* This mapspace is redundant for this hypercall */
-        if ( xatpr.space == XENMAPSPACE_gmfn_range )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatpr.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
-
-        rcu_unlock_domain(d);
-
-        if ( rc && copy_to_guest(arg, &xatpr, 1) )
-            rc = -EFAULT;
-
-        if ( rc == -EAGAIN )
-            rc = hypercall_create_continuation(
-                __HYPERVISOR_memory_op, "ih", op, arg);
-
-        return rc;
-    }
     /* XXX: memsharing not working yet */
     case XENMEM_get_sharing_shared_pages:
     case XENMEM_get_sharing_freed_pages:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -598,6 +598,57 @@ static int xenmem_add_to_physmap(struct 
     return rc;
 }
 
+static int xenmem_add_to_physmap_range(struct domain *d,
+                                       struct xen_add_to_physmap_range *xatpr)
+{
+    int rc;
+
+    while ( xatpr->size > 0 )
+    {
+        xen_ulong_t idx;
+        xen_pfn_t gpfn;
+
+        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        rc = xenmem_add_to_physmap_one(d, xatpr->space,
+                                       xatpr->foreign_domid,
+                                       idx, gpfn);
+
+        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        guest_handle_add_offset(xatpr->idxs, 1);
+        guest_handle_add_offset(xatpr->gpfns, 1);
+        guest_handle_add_offset(xatpr->errs, 1);
+        xatpr->size--;
+
+        /* Check for continuation if it's not the last interation. */
+        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            goto out;
+        }
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -763,6 +814,44 @@ long do_memory_op(unsigned long cmd, XEN
         return rc;
     }
 
+    case XENMEM_add_to_physmap_range:
+    {
+        struct xen_add_to_physmap_range xatpr;
+        struct domain *d;
+
+        if ( copy_from_guest(&xatpr, arg, 1) ||
+             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
+             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
+             !guest_handle_okay(xatpr.errs, xatpr.size) )
+            return -EFAULT;
+
+        d = rcu_lock_domain_by_any_id(xatpr.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap_range(d, &xatpr);
+
+        rcu_unlock_domain(d);
+
+        if ( rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatpr, 1) )
+                rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

Re: [PATCH 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Tim Deegan]

At 14:35 +0000 on 18 Dec (1387373737), Jan Beulich wrote:
> There's really nothing really architecture specific here; the
> architecture specific handling is limited to
> xenmem_add_to_physmap_one().
> 
> Note the restriction of XENMAPSPACE_gmfn_range only being supported
> through XENMEM_add_to_physmap is being dropped as being pointless.

Hmmm.   With that restriction removed, this: 

> +        rc = xenmem_add_to_physmap_one(d, xatpr->space,
> +                                       xatpr->foreign_domid,
> +                                       idx, gpfn);
> +
> +        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
> +        {
> +            rc = -EFAULT;
> +            goto out;
> +        }
> +
> +        guest_handle_add_offset(xatpr->idxs, 1);
> +        guest_handle_add_offset(xatpr->gpfns, 1);
> +        guest_handle_add_offset(xatpr->errs, 1);
> +        xatpr->size--;
> +
> +        /* Check for continuation if it's not the last interation. */
> +        if ( xatpr->size > 0 && hypercall_preempt_check() )
> +        {
> +            rc = -EAGAIN;
> +            goto out;
> +        }

will save the partial result of a preempted XENMAPSPACE_gmfn_range
sub-op into the errors array, and then the whole operation may or may
not return -EAGAIN.

I guess the caller now has enough information to figure out what
happened and restart, but given that the rest of this interface nicely
hides preemption from the caller, it's a bit of an ugly corner case.

Tim.

Re: [PATCH 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Jan Beulich]

>>> On 18.12.13 at 16:59, Tim Deegan <tim@xen.org> wrote:
> At 14:35 +0000 on 18 Dec (1387373737), Jan Beulich wrote:
>> There's really nothing really architecture specific here; the
>> architecture specific handling is limited to
>> xenmem_add_to_physmap_one().
>> 
>> Note the restriction of XENMAPSPACE_gmfn_range only being supported
>> through XENMEM_add_to_physmap is being dropped as being pointless.
> 
> Hmmm.   With that restriction removed, this: 
> 
>> +        rc = xenmem_add_to_physmap_one(d, xatpr->space,
>> +                                       xatpr->foreign_domid,
>> +                                       idx, gpfn);
>> +
>> +        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
>> +        {
>> +            rc = -EFAULT;
>> +            goto out;
>> +        }
>> +
>> +        guest_handle_add_offset(xatpr->idxs, 1);
>> +        guest_handle_add_offset(xatpr->gpfns, 1);
>> +        guest_handle_add_offset(xatpr->errs, 1);
>> +        xatpr->size--;
>> +
>> +        /* Check for continuation if it's not the last interation. */
>> +        if ( xatpr->size > 0 && hypercall_preempt_check() )
>> +        {
>> +            rc = -EAGAIN;
>> +            goto out;
>> +        }
> 
> will save the partial result of a preempted XENMAPSPACE_gmfn_range
> sub-op into the errors array, and then the whole operation may or may
> not return -EAGAIN.
> 
> I guess the caller now has enough information to figure out what
> happened and restart, but given that the rest of this interface nicely
> hides preemption from the caller, it's a bit of an ugly corner case.

I'm afraid I don't follow: XENMAPSPACE_gmfn_range and
XENMAPSPACE_gmfn will be treated equally now - there simply
is no range being specified for the individual
add_to_physmap_range elements. After all,
xenmem_add_to_physmap_one() - as its name says - really only
processes a single page.

Jan

Re: [PATCH 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Tim Deegan]

At 16:08 +0000 on 18 Dec (1387379324), Jan Beulich wrote:
> >>> On 18.12.13 at 16:59, Tim Deegan <tim@xen.org> wrote:
> > At 14:35 +0000 on 18 Dec (1387373737), Jan Beulich wrote:
> >> There's really nothing really architecture specific here; the
> >> architecture specific handling is limited to
> >> xenmem_add_to_physmap_one().
> >> 
> >> Note the restriction of XENMAPSPACE_gmfn_range only being supported
> >> through XENMEM_add_to_physmap is being dropped as being pointless.
> > 
> > Hmmm.   With that restriction removed, this: 
> > 
> >> +        rc = xenmem_add_to_physmap_one(d, xatpr->space,
> >> +                                       xatpr->foreign_domid,
> >> +                                       idx, gpfn);
> >> +
> >> +        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
> >> +        {
> >> +            rc = -EFAULT;
> >> +            goto out;
> >> +        }
> >> +
> >> +        guest_handle_add_offset(xatpr->idxs, 1);
> >> +        guest_handle_add_offset(xatpr->gpfns, 1);
> >> +        guest_handle_add_offset(xatpr->errs, 1);
> >> +        xatpr->size--;
> >> +
> >> +        /* Check for continuation if it's not the last interation. */
> >> +        if ( xatpr->size > 0 && hypercall_preempt_check() )
> >> +        {
> >> +            rc = -EAGAIN;
> >> +            goto out;
> >> +        }
> > 
> > will save the partial result of a preempted XENMAPSPACE_gmfn_range
> > sub-op into the errors array, and then the whole operation may or may
> > not return -EAGAIN.
> > 
> > I guess the caller now has enough information to figure out what
> > happened and restart, but given that the rest of this interface nicely
> > hides preemption from the caller, it's a bit of an ugly corner case.
> 
> I'm afraid I don't follow: XENMAPSPACE_gmfn_range and
> XENMAPSPACE_gmfn will be treated equally now - there simply
> is no range being specified for the individual
> add_to_physmap_range elements.

Oh of course.  Then it's just a slightly odd API, but I guess no
odder this way than before, and with slightly less code. :)  So
Reviewed-by: Tim Deegan <tim@xen.org> for 3/4 and 4/4 as they stand.

Cheers,

Tim.

Re: [PATCH 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Ian Campbell]

On Wed, 2013-12-18 at 14:35 +0000, Jan Beulich wrote:
> There's really nothing really architecture specific here; the
> architecture specific handling is limited to
> xenmem_add_to_physmap_one().
> 
> Note the restriction of XENMAPSPACE_gmfn_range only being supported
> through XENMEM_add_to_physmap is being dropped as being pointless.

Note that this will still not work on ARM where add_to_physmap_one()
does not support the gmfn_range and will still return ENOSYS.

If you are dropping this restriction then xen/include/public/memory.h
will need updating (likewise the first patch).

Personally I think that having two redundant ways of doing the same
thing is the more pointless of the two. Especially given the need to
think a bit carefully about what XENMEM_add_to_physmap_range
XENMAPSPACE_gmfn_range might mean...

> This further eliminates the erroneous bailing from
> xenmem_add_to_physmap_range() if xenmem_add_to_physmap_one() fails.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -1056,103 +1056,10 @@ int xenmem_add_to_physmap_one(
>      return rc;
>  }
>  
> -static int xenmem_add_to_physmap_range(struct domain *d,
> -                                       struct xen_add_to_physmap_range *xatpr)
> -{
> -    int rc;
> -
> -    while ( xatpr->size > 0 )
> -    {
> -        xen_ulong_t idx;
> -        xen_pfn_t gpfn;
> -
> -        if ( unlikely(copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
> -        {
> -            rc = -EFAULT;
> -            goto out;
> -        }
> -
> -        if ( unlikely(copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
> -        {
> -            rc = -EFAULT;
> -            goto out;
> -        }
> -
> -        rc = xenmem_add_to_physmap_one(d, xatpr->space,
> -                                       xatpr->foreign_domid,
> -                                       idx, gpfn);
> -
> -        if ( unlikely(copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
> -        {
> -            rc = -EFAULT;
> -            goto out;
> -        }
> -
> -        if ( rc < 0 )
> -            goto out;
> -
> -        guest_handle_add_offset(xatpr->idxs, 1);
> -        guest_handle_add_offset(xatpr->gpfns, 1);
> -        guest_handle_add_offset(xatpr->errs, 1);
> -        xatpr->size--;
> -
> -        /* Check for continuation if it's not the last interation */
> -        if ( xatpr->size > 0 && hypercall_preempt_check() )
> -        {
> -            rc = -EAGAIN;
> -            goto out;
> -        }
> -    }
> -
> -    rc = 0;
> -
> -out:
> -    return rc;
> -
> -}
> -
>  long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
>  {
> -    int rc;
> -
>      switch ( op )
>      {
> -    case XENMEM_add_to_physmap_range:
> -    {
> -        struct xen_add_to_physmap_range xatpr;
> -        struct domain *d;
> -
> -        if ( copy_from_guest(&xatpr, arg, 1) )
> -            return -EFAULT;
> -
> -        /* This mapspace is redundant for this hypercall */
> -        if ( xatpr.space == XENMAPSPACE_gmfn_range )
> -            return -EINVAL;
> -
> -        d = rcu_lock_domain_by_any_id(xatpr.domid);
> -        if ( d == NULL )
> -            return -ESRCH;
> -
> -        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
> -        if ( rc )
> -        {
> -            rcu_unlock_domain(d);
> -            return rc;
> -        }
> -
> -        rc = xenmem_add_to_physmap_range(d, &xatpr);
> -
> -        rcu_unlock_domain(d);
> -
> -        if ( rc && copy_to_guest(arg, &xatpr, 1) )
> -            rc = -EFAULT;
> -
> -        if ( rc == -EAGAIN )
> -            rc = hypercall_create_continuation(
> -                __HYPERVISOR_memory_op, "ih", op, arg);
> -
> -        return rc;
> -    }
>      /* XXX: memsharing not working yet */
>      case XENMEM_get_sharing_shared_pages:
>      case XENMEM_get_sharing_freed_pages:
> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -598,6 +598,57 @@ static int xenmem_add_to_physmap(struct 
>      return rc;
>  }
>  
> +static int xenmem_add_to_physmap_range(struct domain *d,
> +                                       struct xen_add_to_physmap_range *xatpr)
> +{
> +    int rc;
> +
> +    while ( xatpr->size > 0 )
> +    {
> +        xen_ulong_t idx;
> +        xen_pfn_t gpfn;
> +
> +        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
> +        {
> +            rc = -EFAULT;
> +            goto out;
> +        }
> +
> +        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
> +        {
> +            rc = -EFAULT;
> +            goto out;
> +        }
> +
> +        rc = xenmem_add_to_physmap_one(d, xatpr->space,
> +                                       xatpr->foreign_domid,
> +                                       idx, gpfn);
> +
> +        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
> +        {
> +            rc = -EFAULT;
> +            goto out;
> +        }
> +
> +        guest_handle_add_offset(xatpr->idxs, 1);
> +        guest_handle_add_offset(xatpr->gpfns, 1);
> +        guest_handle_add_offset(xatpr->errs, 1);
> +        xatpr->size--;
> +
> +        /* Check for continuation if it's not the last interation. */
> +        if ( xatpr->size > 0 && hypercall_preempt_check() )
> +        {
> +            rc = -EAGAIN;
> +            goto out;
> +        }
> +    }
> +
> +    rc = 0;
> +
> +out:
> +    return rc;
> +}
> +
>  long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>  {
>      struct domain *d;
> @@ -763,6 +814,44 @@ long do_memory_op(unsigned long cmd, XEN
>          return rc;
>      }
>  
> +    case XENMEM_add_to_physmap_range:
> +    {
> +        struct xen_add_to_physmap_range xatpr;
> +        struct domain *d;
> +
> +        if ( copy_from_guest(&xatpr, arg, 1) ||
> +             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
> +             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
> +             !guest_handle_okay(xatpr.errs, xatpr.size) )
> +            return -EFAULT;
> +
> +        d = rcu_lock_domain_by_any_id(xatpr.domid);
> +        if ( d == NULL )
> +            return -ESRCH;
> +
> +        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
> +        if ( rc )
> +        {
> +            rcu_unlock_domain(d);
> +            return rc;
> +        }
> +
> +        rc = xenmem_add_to_physmap_range(d, &xatpr);
> +
> +        rcu_unlock_domain(d);
> +
> +        if ( rc == -EAGAIN )
> +        {
> +            if ( !__copy_to_guest(arg, &xatpr, 1) )
> +                rc = hypercall_create_continuation(
> +                    __HYPERVISOR_memory_op, "ih", op, arg);
> +            else
> +                rc = -EFAULT;
> +        }
> +
> +        return rc;
> +    }
> +
>      case XENMEM_remove_from_physmap:
>      {
>          struct xen_remove_from_physmap xrfp;
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel

Re: [PATCH 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Jan Beulich]

>>> On 19.12.13 at 11:48, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> On Wed, 2013-12-18 at 14:35 +0000, Jan Beulich wrote:
>> There's really nothing really architecture specific here; the
>> architecture specific handling is limited to
>> xenmem_add_to_physmap_one().
>> 
>> Note the restriction of XENMAPSPACE_gmfn_range only being supported
>> through XENMEM_add_to_physmap is being dropped as being pointless.
> 
> Note that this will still not work on ARM where add_to_physmap_one()
> does not support the gmfn_range and will still return ENOSYS.
> 
> If you are dropping this restriction then xen/include/public/memory.h
> will need updating (likewise the first patch).

I don't think so - we can very well say certain combination are
unsupported even if they happen to work. That leaves us with
the option of dropping back to the earlier state should there
be a need.

> Personally I think that having two redundant ways of doing the same
> thing is the more pointless of the two. Especially given the need to
> think a bit carefully about what XENMEM_add_to_physmap_range
> XENMAPSPACE_gmfn_range might mean...

Yes, that combination is bogus whichever perspective you take.
To some degree also because "range" in the former name is really
wrong - the operation doesn't deal with a range, but with a group
(batch) of individual pages.

However, I meanwhile realized that from an interface perspective
(I'm not proposing to implement this right now!) the combination
could actually be made work - the errs array (being an output only
at present) could be re-used to serve as input to pass the sizes.
The main issue of implementing this would be how to deal with the
two necessary layers of preemption.

So I'm going to re-add the check.

Jan

Re: [PATCH 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Ian Campbell]

On Fri, 2013-12-20 at 07:58 +0000, Jan Beulich wrote:
> >>> On 19.12.13 at 11:48, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> > Personally I think that having two redundant ways of doing the same
> > thing is the more pointless of the two. Especially given the need to
> > think a bit carefully about what XENMEM_add_to_physmap_range
> > XENMAPSPACE_gmfn_range might mean...
> 
> Yes, that combination is bogus whichever perspective you take.
> To some degree also because "range" in the former name is really
> wrong - the operation doesn't deal with a range, but with a group
> (batch) of individual pages.

That's true. I suppose there would be no harm in 
#define XENMEM_add_to_physmap_batch 23
#if __XEN_INTERFACE_VERSION__ < xxx
#define XENMEM_add_to_physmap_range XENMEM_add_to_physmap_batch.
#endif

> However, I meanwhile realized that from an interface perspective
> (I'm not proposing to implement this right now!) the combination
> could actually be made work - the errs array (being an output only
> at present) could be re-used to serve as input to pass the sizes.
> The main issue of implementing this would be how to deal with the
> two necessary layers of preemption.

That's pretty cunning!

> So I'm going to re-add the check.

Given the above I'm doubly in favour of doing so.

Ian.

Re: [PATCH 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Jan Beulich]

>>> On 20.12.13 at 10:09, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> On Fri, 2013-12-20 at 07:58 +0000, Jan Beulich wrote:
>> >>> On 19.12.13 at 11:48, Ian Campbell <Ian.Campbell@citrix.com> wrote:
>> > Personally I think that having two redundant ways of doing the same
>> > thing is the more pointless of the two. Especially given the need to
>> > think a bit carefully about what XENMEM_add_to_physmap_range
>> > XENMAPSPACE_gmfn_range might mean...
>> 
>> Yes, that combination is bogus whichever perspective you take.
>> To some degree also because "range" in the former name is really
>> wrong - the operation doesn't deal with a range, but with a group
>> (batch) of individual pages.
> 
> That's true. I suppose there would be no harm in 
> #define XENMEM_add_to_physmap_batch 23
> #if __XEN_INTERFACE_VERSION__ < xxx
> #define XENMEM_add_to_physmap_range XENMEM_add_to_physmap_batch.
> #endif

Indeed - patch being prepared.

Jan

[PATCH 4/4] fix XENMEM_add_to_physmap_range preemption handling

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 3036 bytes --]

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs (the one OUT one really refers to the memory pointed to by
that handle rather than the handle itself).

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -599,11 +599,21 @@ static int xenmem_add_to_physmap(struct 
 }
 
 static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
+                                       struct xen_add_to_physmap_range *xatpr,
+                                       unsigned int start)
 {
+    unsigned int done = 0;
     int rc;
 
-    while ( xatpr->size > 0 )
+    if ( xatpr->size < start )
+        return -EILSEQ;
+
+    guest_handle_add_offset(xatpr->idxs, start);
+    guest_handle_add_offset(xatpr->gpfns, start);
+    guest_handle_add_offset(xatpr->errs, start);
+    xatpr->size -= start;
+
+    while ( xatpr->size > done )
     {
         xen_ulong_t idx;
         xen_pfn_t gpfn;
@@ -633,12 +643,11 @@ static int xenmem_add_to_physmap_range(s
         guest_handle_add_offset(xatpr->idxs, 1);
         guest_handle_add_offset(xatpr->gpfns, 1);
         guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
 
         /* Check for continuation if it's not the last interation. */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        if ( xatpr->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             goto out;
         }
     }
@@ -819,6 +828,13 @@ long do_memory_op(unsigned long cmd, XEN
         struct xen_add_to_physmap_range xatpr;
         struct domain *d;
 
+        BUILD_BUG_ON((typeof(xatpr.size))-1 >
+                     (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for faked input. */
+        if ( start_extent != (typeof(xatpr.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatpr, arg, 1) ||
              !guest_handle_okay(xatpr.idxs, xatpr.size) ||
              !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
@@ -836,18 +852,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
+        rc = xenmem_add_to_physmap_range(d, &xatpr, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatpr, 1) )
-                rc = hypercall_create_continuation(
-                    __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( rc > 0 )
+            rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "lh",
+                    op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }




[-- Attachment #2: xatpr-preemption.patch --]
[-- Type: text/plain, Size: 3085 bytes --]

fix XENMEM_add_to_physmap_range preemption handling

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs (the one OUT one really refers to the memory pointed to by
that handle rather than the handle itself).

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -599,11 +599,21 @@ static int xenmem_add_to_physmap(struct 
 }
 
 static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
+                                       struct xen_add_to_physmap_range *xatpr,
+                                       unsigned int start)
 {
+    unsigned int done = 0;
     int rc;
 
-    while ( xatpr->size > 0 )
+    if ( xatpr->size < start )
+        return -EILSEQ;
+
+    guest_handle_add_offset(xatpr->idxs, start);
+    guest_handle_add_offset(xatpr->gpfns, start);
+    guest_handle_add_offset(xatpr->errs, start);
+    xatpr->size -= start;
+
+    while ( xatpr->size > done )
     {
         xen_ulong_t idx;
         xen_pfn_t gpfn;
@@ -633,12 +643,11 @@ static int xenmem_add_to_physmap_range(s
         guest_handle_add_offset(xatpr->idxs, 1);
         guest_handle_add_offset(xatpr->gpfns, 1);
         guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
 
         /* Check for continuation if it's not the last interation. */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        if ( xatpr->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             goto out;
         }
     }
@@ -819,6 +828,13 @@ long do_memory_op(unsigned long cmd, XEN
         struct xen_add_to_physmap_range xatpr;
         struct domain *d;
 
+        BUILD_BUG_ON((typeof(xatpr.size))-1 >
+                     (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for faked input. */
+        if ( start_extent != (typeof(xatpr.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatpr, arg, 1) ||
              !guest_handle_okay(xatpr.idxs, xatpr.size) ||
              !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
@@ -836,18 +852,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
+        rc = xenmem_add_to_physmap_range(d, &xatpr, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatpr, 1) )
-                rc = hypercall_create_continuation(
-                    __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( rc > 0 )
+            rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "lh",
+                    op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

Re: [PATCH 0/4] fix preemption handling for XENMEM_add_to_physmap_range{, _range}

[Ian Campbell]

On Wed, 2013-12-18 at 14:29 +0000, Jan Beulich wrote:
> The hypervisor isn't supposed to use the input structures for
> storing continuation information - only fields explicitly used as
> hypercall outputs should ever be updated.
> 
> Obviously this implies an ABI change, but since the previous
> behavior was not intended to be that way I don't think we should
> stick to the old behavior.

FWIW I don't think adding const to a function parameter (which is
kinda-sorta what we are doing here) constitutes a change to the ABI as
such (or not a meaningful one), since a non-const can always be const'ed
on call.

> There's one caveat though - with the previous model, the caller
> could - upon failure - use the updated structure to find out how
> by progress was made. However, that wasn't intended afaict,
> largely supported by this information depending on hypervisor
> internals (i.e. the caller would have to know the order of request 
> processing and the meaning of the respective size fields, which
> aren't simply saying "this much was processed").

IIRC the long standing user of the original physmap range functionality
was hvmloader (something to do with batching IOMMU TLB flushes?). If
hvmloader isn't introspecting hypervisor internals in this way I doubt
anyone else is.

I suppose this series is proposed for 4.5 rather than 4.4 since you
didn't say otherwise?

> 
> Consequently, as a follow-up we may want to consider making
> explicit (and straight forward) this progress indication on error.
> 
> 1: move XENMEM_add_to_physmap handling framework to common code
> 2: fix XENMEM_add_to_physmap preemption handling
> 3: move XENMEM_add_to_physmap_range handling framework to common code
> 4: fix XENMEM_add_to_physmap_range preemption handling
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> 

Re: [PATCH 0/4] fix preemption handling for XENMEM_add_to_physmap_range{, _range}

[Jan Beulich]

>>> On 18.12.13 at 15:43, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> I suppose this series is proposed for 4.5 rather than 4.4 since you
> didn't say otherwise?

Actually I'd be wanting this in 4.4 (and applicable parts even
backported) since it's a bug fix (and as such I didn't think I'd need
to say this explicitly).

Jan

Re: [PATCH 0/4] fix preemption handling for XENMEM_add_to_physmap_range{, _range}

[Keir Fraser]

On 18/12/2013 14:29, "Jan Beulich" <JBeulich@suse.com> wrote:

> The hypervisor isn't supposed to use the input structures for
> storing continuation information - only fields explicitly used as
> hypercall outputs should ever be updated.
> 
> Obviously this implies an ABI change, but since the previous
> behavior was not intended to be that way I don't think we should
> stick to the old behavior.
> 
> There's one caveat though - with the previous model, the caller
> could - upon failure - use the updated structure to find out how
> by progress was made. However, that wasn't intended afaict,
> largely supported by this information depending on hypervisor
> internals (i.e. the caller would have to know the order of request
> processing and the meaning of the respective size fields, which
> aren't simply saying "this much was processed").
> 
> Consequently, as a follow-up we may want to consider making
> explicit (and straight forward) this progress indication on error.
> 
> 1: move XENMEM_add_to_physmap handling framework to common code
> 2: fix XENMEM_add_to_physmap preemption handling
> 3: move XENMEM_add_to_physmap_range handling framework to common code
> 4: fix XENMEM_add_to_physmap_range preemption handling
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Nice to have this fixed!

Acked-by: Keir Fraser <keir@xen.org>

[PATCH v2 0/4] fix preemption handling for XENMEM_add_to_physmap_range{, _range}

[Jan Beulich]

>>> On 18.12.13 at 15:29, "Jan Beulich" <JBeulich@suse.com> wrote:
The hypervisor isn't supposed to use the input structures for
storing continuation information - only fields explicitly used as
hypercall outputs should ever be updated.

Obviously this implies an ABI change, but since the previous
behavior was not intended to be that way I don't think we should
stick to the old behavior.

There's one caveat though - with the previous model, the caller
could - upon failure - use the updated structure to find out how
by progress was made. However, that wasn't intended afaict,
largely supported by this information depending on hypervisor
internals (i.e. the caller would have to know the order of request 
processing and the meaning of the respective size fields, which
aren't simply saying "this much was processed").

Consequently, as a follow-up we may want to consider making
explicit (and straight forward) this progress indication on error.

1: move XENMEM_add_to_physmap handling framework to common code
2: fix XENMEM_add_to_physmap preemption handling
3: move XENMEM_add_to_physmap_range handling framework to common code
4: fix XENMEM_add_to_physmap_range preemption handling

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: Apart from the removal of a bogus ASSERT() as requested
    by Tim, only a couple minor/cosmetic changes (see individual
    patches), hence I'm retaining the tags that were already
    given for v1.

[PATCH v2 1/4] move XENMEM_add_to_physmap handling framework to common code

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 14274 bytes --]

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
supported through XENMEM_add_to_physmap_range is being dropped as being
pointless.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -968,7 +968,7 @@ void share_xen_page_with_privileged_gues
     share_xen_page_with_guest(page, dom_xen, readonly);
 }
 
-static int xenmem_add_to_physmap_one(
+int xenmem_add_to_physmap_one(
     struct domain *d,
     uint16_t space,
     domid_t foreign_domid,
@@ -1118,37 +1118,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        /* Foreign mapping is only supported by add_to_physmap_range */
-        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatp.space, DOMID_INVALID,
-                                       xatp.idx, xatp.gpfn);
-
-        rcu_unlock_domain(d);
-
-        return rc;
-    }
-
     case XENMEM_add_to_physmap_range:
     {
         struct xen_add_to_physmap_range xatpr;
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4520,20 +4520,23 @@ static int handle_iomem_range(unsigned l
     return 0;
 }
 
-static int xenmem_add_to_physmap_once(
+int xenmem_add_to_physmap_one(
     struct domain *d,
-    const struct xen_add_to_physmap *xatp)
+    uint16_t space,
+    domid_t foreign_domid,
+    unsigned long idx,
+    xen_pfn_t gpfn)
 {
     struct page_info *page = NULL;
     unsigned long gfn = 0; /* gcc ... */
-    unsigned long prev_mfn, mfn = 0, gpfn, idx;
+    unsigned long prev_mfn, mfn = 0, old_gpfn;
     int rc;
     p2m_type_t p2mt;
 
-    switch ( xatp->space )
+    switch ( space )
     {
         case XENMAPSPACE_shared_info:
-            if ( xatp->idx == 0 )
+            if ( idx == 0 )
                 mfn = virt_to_mfn(d->shared_info);
             break;
         case XENMAPSPACE_grant_table:
@@ -4542,9 +4545,8 @@ static int xenmem_add_to_physmap_once(
             if ( d->grant_table->gt_version == 0 )
                 d->grant_table->gt_version = 1;
 
-            idx = xatp->idx;
             if ( d->grant_table->gt_version == 2 &&
-                 (xatp->idx & XENMAPIDX_grant_table_status) )
+                 (idx & XENMAPIDX_grant_table_status) )
             {
                 idx &= ~XENMAPIDX_grant_table_status;
                 if ( idx < nr_status_frames(d->grant_table) )
@@ -4566,9 +4568,9 @@ static int xenmem_add_to_physmap_once(
         case XENMAPSPACE_gmfn:
         {
             p2m_type_t p2mt;
-            gfn = xatp->idx;
 
-            idx = mfn_x(get_gfn_unshare(d, xatp->idx, &p2mt));
+            gfn = idx;
+            idx = mfn_x(get_gfn_unshare(d, idx, &p2mt));
             /* If the page is still shared, exit early */
             if ( p2m_is_shared(p2mt) )
             {
@@ -4589,41 +4591,38 @@ static int xenmem_add_to_physmap_once(
     {
         if ( page )
             put_page(page);
-        if ( xatp->space == XENMAPSPACE_gmfn ||
-             xatp->space == XENMAPSPACE_gmfn_range )
+        if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
             put_gfn(d, gfn);
         return -EINVAL;
     }
 
     /* Remove previously mapped page if it was present. */
-    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
+    prev_mfn = mfn_x(get_gfn(d, gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
     {
         if ( is_xen_heap_mfn(prev_mfn) )
             /* Xen heap frames are simply unhooked from this phys slot. */
-            guest_physmap_remove_page(d, xatp->gpfn, prev_mfn, PAGE_ORDER_4K);
+            guest_physmap_remove_page(d, gpfn, prev_mfn, PAGE_ORDER_4K);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */
-            guest_remove_page(d, xatp->gpfn);
+            guest_remove_page(d, gpfn);
     }
     /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */
-    put_gfn(d, xatp->gpfn);
+    put_gfn(d, gpfn);
 
     /* Unmap from old location, if any. */
-    gpfn = get_gpfn_from_mfn(mfn);
-    ASSERT( gpfn != SHARED_M2P_ENTRY );
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
-        ASSERT( gpfn == gfn );
-    if ( gpfn != INVALID_M2P_ENTRY )
-        guest_physmap_remove_page(d, gpfn, mfn, PAGE_ORDER_4K);
+    old_gpfn = get_gpfn_from_mfn(mfn);
+    ASSERT( old_gpfn != SHARED_M2P_ENTRY );
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
+        ASSERT( old_gpfn == gfn );
+    if ( old_gpfn != INVALID_M2P_ENTRY )
+        guest_physmap_remove_page(d, old_gpfn, mfn, PAGE_ORDER_4K);
 
     /* Map at new location. */
-    rc = guest_physmap_add_page(d, xatp->gpfn, mfn, PAGE_ORDER_4K);
+    rc = guest_physmap_add_page(d, gpfn, mfn, PAGE_ORDER_4K);
 
     /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
         put_gfn(d, gfn);
 
     if ( page )
@@ -4632,90 +4631,12 @@ static int xenmem_add_to_physmap_once(
     return rc;
 }
 
-static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
-{
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
-
-    if ( xatp->space == XENMAPSPACE_gmfn_range )
-    {
-        if ( need_iommu(d) )
-            this_cpu(iommu_dont_flush_iotlb) = 1;
-
-        start_xatp = *xatp;
-        while ( xatp->size > 0 )
-        {
-            rc = xenmem_add_to_physmap_once(d, xatp);
-            if ( rc < 0 )
-                break;
-
-            xatp->idx++;
-            xatp->gpfn++;
-            xatp->size--;
-
-            /* Check for continuation if it's not the last interation */
-            if ( xatp->size > 0 && hypercall_preempt_check() )
-            {
-                rc = -EAGAIN;
-                break;
-            }
-        }
-
-        if ( need_iommu(d) )
-        {
-            this_cpu(iommu_dont_flush_iotlb) = 0;
-            iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-            iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
-        }
-
-        return rc;
-    }
-
-    return xenmem_add_to_physmap_once(d, xatp);
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     int rc;
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
-        {
-            rcu_unlock_domain(d);
-            return -EPERM;
-        }
-
-        rc = xenmem_add_to_physmap(d, &xatp);
-
-        rcu_unlock_domain(d);
-
-        if ( xatp.space == XENMAPSPACE_gmfn_range )
-        {
-            if ( rc && __copy_to_guest(arg, &xatp, 1) )
-                rc = -EFAULT;
-
-            if ( rc == -EAGAIN )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-        }
-
-        return rc;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct xen_foreign_memory_map fmap;
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -55,34 +55,6 @@ int compat_arch_memory_op(int op, XEN_GU
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct compat_add_to_physmap cmp;
-        struct xen_add_to_physmap *nat = COMPAT_ARG_XLAT_VIRT_BASE;
-
-        if ( copy_from_guest(&cmp, arg, 1) )
-            return -EFAULT;
-
-        XLAT_add_to_physmap(nat, &cmp);
-        rc = arch_memory_op(op, guest_handle_from_ptr(nat, void));
-
-        if ( !rc || cmp.space != XENMAPSPACE_gmfn_range )
-            break;
-
-        XLAT_add_to_physmap(&cmp, nat);
-        if ( __copy_to_guest(arg, &cmp, 1) )
-        {
-            if ( rc == __HYPERVISOR_memory_op )
-                hypercall_cancel_continuation();
-            return -EFAULT;
-        }
-
-        if ( rc == __HYPERVISOR_memory_op )
-            hypercall_xlat_continuation(NULL, 0x2, nat, arg);
-
-        break;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct compat_foreign_memory_map cmp;
--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -26,11 +26,13 @@ int compat_memory_op(unsigned int cmd, X
             XEN_GUEST_HANDLE_PARAM(void) hnd;
             struct xen_memory_reservation *rsrv;
             struct xen_memory_exchange *xchg;
+            struct xen_add_to_physmap *atp;
             struct xen_remove_from_physmap *xrfp;
         } nat;
         union {
             struct compat_memory_reservation rsrv;
             struct compat_memory_exchange xchg;
+            struct compat_add_to_physmap atp;
         } cmp;
 
         set_xen_guest_handle(nat.hnd, COMPAT_ARG_XLAT_VIRT_BASE);
@@ -187,6 +189,14 @@ int compat_memory_op(unsigned int cmd, X
             nat.hnd = compat;
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( copy_from_guest(&cmp.atp, compat, 1) )
+                return -EFAULT;
+
+            XLAT_add_to_physmap(nat.atp, &cmp.atp);
+
+            break;
+
         case XENMEM_remove_from_physmap:
         {
             struct compat_remove_from_physmap cmp;
@@ -315,6 +325,16 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_remove_from_physmap:
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
+                break;
+
+            XLAT_add_to_physmap(&cmp.atp, nat.atp);
+            if ( __copy_to_guest(compat, &cmp.atp, 1) )
+                rc = -EFAULT;
+
+            break;
+
         default:
             domain_crash(current->domain);
             split = 0;
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -542,6 +542,53 @@ static long memory_exchange(XEN_GUEST_HA
     return rc;
 }
 
+static int xenmem_add_to_physmap(struct domain *d,
+                                 struct xen_add_to_physmap *xatp)
+{
+    struct xen_add_to_physmap start_xatp;
+    int rc = 0;
+
+    if ( xatp->space != XENMAPSPACE_gmfn_range )
+        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                         xatp->idx, xatp->gpfn);
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+        this_cpu(iommu_dont_flush_iotlb) = 1;
+#endif
+
+    start_xatp = *xatp;
+    while ( xatp->size > 0 )
+    {
+        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                       xatp->idx, xatp->gpfn);
+        if ( rc < 0 )
+            break;
+
+        xatp->idx++;
+        xatp->gpfn++;
+        xatp->size--;
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( xatp->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            break;
+        }
+    }
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+    {
+        this_cpu(iommu_dont_flush_iotlb) = 0;
+        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+    }
+#endif
+
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -673,6 +720,40 @@ long do_memory_op(unsigned long cmd, XEN
 
         break;
 
+    case XENMEM_add_to_physmap:
+    {
+        struct xen_add_to_physmap xatp;
+
+        if ( copy_from_guest(&xatp, arg, 1) )
+            return -EFAULT;
+
+        d = rcu_lock_domain_by_any_id(xatp.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap(d, &xatp);
+
+        rcu_unlock_domain(d);
+
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatp, 1) )
+                rc = hypercall_create_continuation(
+                        __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -356,6 +356,10 @@ static inline unsigned int get_order_fro
 
 void scrub_one_page(struct page_info *);
 
+int xenmem_add_to_physmap_one(struct domain *d, uint16_t space,
+                              domid_t foreign_domid,
+                              unsigned long idx, xen_pfn_t gpfn);
+
 /* Returns 1 on success, 0 on error, negative if the ring
  * for event propagation is full in the presence of paging */
 int guest_remove_page(struct domain *d, unsigned long gmfn);



[-- Attachment #2: xatp-common.patch --]
[-- Type: text/plain, Size: 14334 bytes --]

move XENMEM_add_to_physmap handling framework to common code

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

Note that ARM's restriction of XENMAPSPACE_gmfn_foreign only being
supported through XENMEM_add_to_physmap_range is being dropped as being
pointless.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -968,7 +968,7 @@ void share_xen_page_with_privileged_gues
     share_xen_page_with_guest(page, dom_xen, readonly);
 }
 
-static int xenmem_add_to_physmap_one(
+int xenmem_add_to_physmap_one(
     struct domain *d,
     uint16_t space,
     domid_t foreign_domid,
@@ -1118,37 +1118,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        /* Foreign mapping is only supported by add_to_physmap_range */
-        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatp.space, DOMID_INVALID,
-                                       xatp.idx, xatp.gpfn);
-
-        rcu_unlock_domain(d);
-
-        return rc;
-    }
-
     case XENMEM_add_to_physmap_range:
     {
         struct xen_add_to_physmap_range xatpr;
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4520,20 +4520,23 @@ static int handle_iomem_range(unsigned l
     return 0;
 }
 
-static int xenmem_add_to_physmap_once(
+int xenmem_add_to_physmap_one(
     struct domain *d,
-    const struct xen_add_to_physmap *xatp)
+    uint16_t space,
+    domid_t foreign_domid,
+    unsigned long idx,
+    xen_pfn_t gpfn)
 {
     struct page_info *page = NULL;
     unsigned long gfn = 0; /* gcc ... */
-    unsigned long prev_mfn, mfn = 0, gpfn, idx;
+    unsigned long prev_mfn, mfn = 0, old_gpfn;
     int rc;
     p2m_type_t p2mt;
 
-    switch ( xatp->space )
+    switch ( space )
     {
         case XENMAPSPACE_shared_info:
-            if ( xatp->idx == 0 )
+            if ( idx == 0 )
                 mfn = virt_to_mfn(d->shared_info);
             break;
         case XENMAPSPACE_grant_table:
@@ -4542,9 +4545,8 @@ static int xenmem_add_to_physmap_once(
             if ( d->grant_table->gt_version == 0 )
                 d->grant_table->gt_version = 1;
 
-            idx = xatp->idx;
             if ( d->grant_table->gt_version == 2 &&
-                 (xatp->idx & XENMAPIDX_grant_table_status) )
+                 (idx & XENMAPIDX_grant_table_status) )
             {
                 idx &= ~XENMAPIDX_grant_table_status;
                 if ( idx < nr_status_frames(d->grant_table) )
@@ -4566,9 +4568,9 @@ static int xenmem_add_to_physmap_once(
         case XENMAPSPACE_gmfn:
         {
             p2m_type_t p2mt;
-            gfn = xatp->idx;
 
-            idx = mfn_x(get_gfn_unshare(d, xatp->idx, &p2mt));
+            gfn = idx;
+            idx = mfn_x(get_gfn_unshare(d, idx, &p2mt));
             /* If the page is still shared, exit early */
             if ( p2m_is_shared(p2mt) )
             {
@@ -4589,41 +4591,38 @@ static int xenmem_add_to_physmap_once(
     {
         if ( page )
             put_page(page);
-        if ( xatp->space == XENMAPSPACE_gmfn ||
-             xatp->space == XENMAPSPACE_gmfn_range )
+        if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
             put_gfn(d, gfn);
         return -EINVAL;
     }
 
     /* Remove previously mapped page if it was present. */
-    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
+    prev_mfn = mfn_x(get_gfn(d, gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
     {
         if ( is_xen_heap_mfn(prev_mfn) )
             /* Xen heap frames are simply unhooked from this phys slot. */
-            guest_physmap_remove_page(d, xatp->gpfn, prev_mfn, PAGE_ORDER_4K);
+            guest_physmap_remove_page(d, gpfn, prev_mfn, PAGE_ORDER_4K);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */
-            guest_remove_page(d, xatp->gpfn);
+            guest_remove_page(d, gpfn);
     }
     /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */
-    put_gfn(d, xatp->gpfn);
+    put_gfn(d, gpfn);
 
     /* Unmap from old location, if any. */
-    gpfn = get_gpfn_from_mfn(mfn);
-    ASSERT( gpfn != SHARED_M2P_ENTRY );
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
-        ASSERT( gpfn == gfn );
-    if ( gpfn != INVALID_M2P_ENTRY )
-        guest_physmap_remove_page(d, gpfn, mfn, PAGE_ORDER_4K);
+    old_gpfn = get_gpfn_from_mfn(mfn);
+    ASSERT( old_gpfn != SHARED_M2P_ENTRY );
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
+        ASSERT( old_gpfn == gfn );
+    if ( old_gpfn != INVALID_M2P_ENTRY )
+        guest_physmap_remove_page(d, old_gpfn, mfn, PAGE_ORDER_4K);
 
     /* Map at new location. */
-    rc = guest_physmap_add_page(d, xatp->gpfn, mfn, PAGE_ORDER_4K);
+    rc = guest_physmap_add_page(d, gpfn, mfn, PAGE_ORDER_4K);
 
     /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
         put_gfn(d, gfn);
 
     if ( page )
@@ -4632,90 +4631,12 @@ static int xenmem_add_to_physmap_once(
     return rc;
 }
 
-static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
-{
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
-
-    if ( xatp->space == XENMAPSPACE_gmfn_range )
-    {
-        if ( need_iommu(d) )
-            this_cpu(iommu_dont_flush_iotlb) = 1;
-
-        start_xatp = *xatp;
-        while ( xatp->size > 0 )
-        {
-            rc = xenmem_add_to_physmap_once(d, xatp);
-            if ( rc < 0 )
-                break;
-
-            xatp->idx++;
-            xatp->gpfn++;
-            xatp->size--;
-
-            /* Check for continuation if it's not the last interation */
-            if ( xatp->size > 0 && hypercall_preempt_check() )
-            {
-                rc = -EAGAIN;
-                break;
-            }
-        }
-
-        if ( need_iommu(d) )
-        {
-            this_cpu(iommu_dont_flush_iotlb) = 0;
-            iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-            iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
-        }
-
-        return rc;
-    }
-
-    return xenmem_add_to_physmap_once(d, xatp);
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     int rc;
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
-        {
-            rcu_unlock_domain(d);
-            return -EPERM;
-        }
-
-        rc = xenmem_add_to_physmap(d, &xatp);
-
-        rcu_unlock_domain(d);
-
-        if ( xatp.space == XENMAPSPACE_gmfn_range )
-        {
-            if ( rc && __copy_to_guest(arg, &xatp, 1) )
-                rc = -EFAULT;
-
-            if ( rc == -EAGAIN )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-        }
-
-        return rc;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct xen_foreign_memory_map fmap;
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -55,34 +55,6 @@ int compat_arch_memory_op(int op, XEN_GU
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct compat_add_to_physmap cmp;
-        struct xen_add_to_physmap *nat = COMPAT_ARG_XLAT_VIRT_BASE;
-
-        if ( copy_from_guest(&cmp, arg, 1) )
-            return -EFAULT;
-
-        XLAT_add_to_physmap(nat, &cmp);
-        rc = arch_memory_op(op, guest_handle_from_ptr(nat, void));
-
-        if ( !rc || cmp.space != XENMAPSPACE_gmfn_range )
-            break;
-
-        XLAT_add_to_physmap(&cmp, nat);
-        if ( __copy_to_guest(arg, &cmp, 1) )
-        {
-            if ( rc == __HYPERVISOR_memory_op )
-                hypercall_cancel_continuation();
-            return -EFAULT;
-        }
-
-        if ( rc == __HYPERVISOR_memory_op )
-            hypercall_xlat_continuation(NULL, 0x2, nat, arg);
-
-        break;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct compat_foreign_memory_map cmp;
--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -26,11 +26,13 @@ int compat_memory_op(unsigned int cmd, X
             XEN_GUEST_HANDLE_PARAM(void) hnd;
             struct xen_memory_reservation *rsrv;
             struct xen_memory_exchange *xchg;
+            struct xen_add_to_physmap *atp;
             struct xen_remove_from_physmap *xrfp;
         } nat;
         union {
             struct compat_memory_reservation rsrv;
             struct compat_memory_exchange xchg;
+            struct compat_add_to_physmap atp;
         } cmp;
 
         set_xen_guest_handle(nat.hnd, COMPAT_ARG_XLAT_VIRT_BASE);
@@ -187,6 +189,14 @@ int compat_memory_op(unsigned int cmd, X
             nat.hnd = compat;
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( copy_from_guest(&cmp.atp, compat, 1) )
+                return -EFAULT;
+
+            XLAT_add_to_physmap(nat.atp, &cmp.atp);
+
+            break;
+
         case XENMEM_remove_from_physmap:
         {
             struct compat_remove_from_physmap cmp;
@@ -315,6 +325,16 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_remove_from_physmap:
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
+                break;
+
+            XLAT_add_to_physmap(&cmp.atp, nat.atp);
+            if ( __copy_to_guest(compat, &cmp.atp, 1) )
+                rc = -EFAULT;
+
+            break;
+
         default:
             domain_crash(current->domain);
             split = 0;
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -542,6 +542,53 @@ static long memory_exchange(XEN_GUEST_HA
     return rc;
 }
 
+static int xenmem_add_to_physmap(struct domain *d,
+                                 struct xen_add_to_physmap *xatp)
+{
+    struct xen_add_to_physmap start_xatp;
+    int rc = 0;
+
+    if ( xatp->space != XENMAPSPACE_gmfn_range )
+        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                         xatp->idx, xatp->gpfn);
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+        this_cpu(iommu_dont_flush_iotlb) = 1;
+#endif
+
+    start_xatp = *xatp;
+    while ( xatp->size > 0 )
+    {
+        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                       xatp->idx, xatp->gpfn);
+        if ( rc < 0 )
+            break;
+
+        xatp->idx++;
+        xatp->gpfn++;
+        xatp->size--;
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( xatp->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            break;
+        }
+    }
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+    {
+        this_cpu(iommu_dont_flush_iotlb) = 0;
+        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+    }
+#endif
+
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -673,6 +720,40 @@ long do_memory_op(unsigned long cmd, XEN
 
         break;
 
+    case XENMEM_add_to_physmap:
+    {
+        struct xen_add_to_physmap xatp;
+
+        if ( copy_from_guest(&xatp, arg, 1) )
+            return -EFAULT;
+
+        d = rcu_lock_domain_by_any_id(xatp.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap(d, &xatp);
+
+        rcu_unlock_domain(d);
+
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatp, 1) )
+                rc = hypercall_create_continuation(
+                        __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -356,6 +356,10 @@ static inline unsigned int get_order_fro
 
 void scrub_one_page(struct page_info *);
 
+int xenmem_add_to_physmap_one(struct domain *d, uint16_t space,
+                              domid_t foreign_domid,
+                              unsigned long idx, xen_pfn_t gpfn);
+
 /* Returns 1 on success, 0 on error, negative if the ring
  * for event propagation is full in the presence of paging */
 int guest_remove_page(struct domain *d, unsigned long gmfn);

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

[PATCH v2 2/4] fix XENMEM_add_to_physmap preemption handling

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 5373 bytes --]

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: drop bogus ASSERT()

--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -190,6 +190,9 @@ int compat_memory_op(unsigned int cmd, X
             break;
 
         case XENMEM_add_to_physmap:
+            BUILD_BUG_ON((typeof(cmp.atp.size))-1 >
+                         (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
             if ( copy_from_guest(&cmp.atp, compat, 1) )
                 return -EFAULT;
 
@@ -322,17 +325,8 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_current_reservation:
         case XENMEM_maximum_reservation:
         case XENMEM_maximum_gpfn:
-        case XENMEM_remove_from_physmap:
-            break;
-
         case XENMEM_add_to_physmap:
-            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
-                break;
-
-            XLAT_add_to_physmap(&cmp.atp, nat.atp);
-            if ( __copy_to_guest(compat, &cmp.atp, 1) )
-                rc = -EFAULT;
-
+        case XENMEM_remove_from_physmap:
             break;
 
         default:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -543,22 +543,29 @@ static long memory_exchange(XEN_GUEST_HA
 }
 
 static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
+                                 struct xen_add_to_physmap *xatp,
+                                 unsigned int start)
 {
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
+    unsigned int done = 0;
+    long rc = 0;
 
     if ( xatp->space != XENMAPSPACE_gmfn_range )
         return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                          xatp->idx, xatp->gpfn);
 
+    if ( xatp->size < start )
+        return -EILSEQ;
+
+    xatp->idx += start;
+    xatp->gpfn += start;
+    xatp->size -= start;
+
 #ifdef HAS_PASSTHROUGH
     if ( need_iommu(d) )
         this_cpu(iommu_dont_flush_iotlb) = 1;
 #endif
 
-    start_xatp = *xatp;
-    while ( xatp->size > 0 )
+    while ( xatp->size > done )
     {
         rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                        xatp->idx, xatp->gpfn);
@@ -567,12 +577,11 @@ static int xenmem_add_to_physmap(struct 
 
         xatp->idx++;
         xatp->gpfn++;
-        xatp->size--;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatp->size > 0 && hypercall_preempt_check() )
+        if ( xatp->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             break;
         }
     }
@@ -581,8 +590,8 @@ static int xenmem_add_to_physmap(struct 
     if ( need_iommu(d) )
     {
         this_cpu(iommu_dont_flush_iotlb) = 0;
-        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, xatp->idx - done, done);
+        iommu_iotlb_flush(d, xatp->gpfn - done, done);
     }
 #endif
 
@@ -594,10 +603,10 @@ long do_memory_op(unsigned long cmd, XEN
     struct domain *d;
     long rc;
     unsigned int address_bits;
-    unsigned long start_extent;
     struct xen_memory_reservation reservation;
     struct memop_args args;
     domid_t domid;
+    unsigned long start_extent = cmd >> MEMOP_EXTENT_SHIFT;
     int op = cmd & MEMOP_CMD_MASK;
 
     switch ( op )
@@ -605,8 +614,6 @@ long do_memory_op(unsigned long cmd, XEN
     case XENMEM_increase_reservation:
     case XENMEM_decrease_reservation:
     case XENMEM_populate_physmap:
-        start_extent = cmd >> MEMOP_EXTENT_SHIFT;
-
         if ( copy_from_guest(&reservation, arg, 1) )
             return start_extent;
 
@@ -724,6 +731,12 @@ long do_memory_op(unsigned long cmd, XEN
     {
         struct xen_add_to_physmap xatp;
 
+        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for faked input. */
+        if ( start_extent != (typeof(xatp.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
@@ -738,18 +751,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap(d, &xatp);
+        rc = xenmem_add_to_physmap(d, &xatp, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatp, 1) )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc > 0 )
+            rc = hypercall_create_continuation(
+                     __HYPERVISOR_memory_op, "lh",
+                     op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }



[-- Attachment #2: xatp-preemption.patch --]
[-- Type: text/plain, Size: 5418 bytes --]

fix XENMEM_add_to_physmap preemption handling

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: drop bogus ASSERT()

--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -190,6 +190,9 @@ int compat_memory_op(unsigned int cmd, X
             break;
 
         case XENMEM_add_to_physmap:
+            BUILD_BUG_ON((typeof(cmp.atp.size))-1 >
+                         (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
             if ( copy_from_guest(&cmp.atp, compat, 1) )
                 return -EFAULT;
 
@@ -322,17 +325,8 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_current_reservation:
         case XENMEM_maximum_reservation:
         case XENMEM_maximum_gpfn:
-        case XENMEM_remove_from_physmap:
-            break;
-
         case XENMEM_add_to_physmap:
-            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
-                break;
-
-            XLAT_add_to_physmap(&cmp.atp, nat.atp);
-            if ( __copy_to_guest(compat, &cmp.atp, 1) )
-                rc = -EFAULT;
-
+        case XENMEM_remove_from_physmap:
             break;
 
         default:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -543,22 +543,29 @@ static long memory_exchange(XEN_GUEST_HA
 }
 
 static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
+                                 struct xen_add_to_physmap *xatp,
+                                 unsigned int start)
 {
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
+    unsigned int done = 0;
+    long rc = 0;
 
     if ( xatp->space != XENMAPSPACE_gmfn_range )
         return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                          xatp->idx, xatp->gpfn);
 
+    if ( xatp->size < start )
+        return -EILSEQ;
+
+    xatp->idx += start;
+    xatp->gpfn += start;
+    xatp->size -= start;
+
 #ifdef HAS_PASSTHROUGH
     if ( need_iommu(d) )
         this_cpu(iommu_dont_flush_iotlb) = 1;
 #endif
 
-    start_xatp = *xatp;
-    while ( xatp->size > 0 )
+    while ( xatp->size > done )
     {
         rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                        xatp->idx, xatp->gpfn);
@@ -567,12 +577,11 @@ static int xenmem_add_to_physmap(struct 
 
         xatp->idx++;
         xatp->gpfn++;
-        xatp->size--;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatp->size > 0 && hypercall_preempt_check() )
+        if ( xatp->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             break;
         }
     }
@@ -581,8 +590,8 @@ static int xenmem_add_to_physmap(struct 
     if ( need_iommu(d) )
     {
         this_cpu(iommu_dont_flush_iotlb) = 0;
-        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, xatp->idx - done, done);
+        iommu_iotlb_flush(d, xatp->gpfn - done, done);
     }
 #endif
 
@@ -594,10 +603,10 @@ long do_memory_op(unsigned long cmd, XEN
     struct domain *d;
     long rc;
     unsigned int address_bits;
-    unsigned long start_extent;
     struct xen_memory_reservation reservation;
     struct memop_args args;
     domid_t domid;
+    unsigned long start_extent = cmd >> MEMOP_EXTENT_SHIFT;
     int op = cmd & MEMOP_CMD_MASK;
 
     switch ( op )
@@ -605,8 +614,6 @@ long do_memory_op(unsigned long cmd, XEN
     case XENMEM_increase_reservation:
     case XENMEM_decrease_reservation:
     case XENMEM_populate_physmap:
-        start_extent = cmd >> MEMOP_EXTENT_SHIFT;
-
         if ( copy_from_guest(&reservation, arg, 1) )
             return start_extent;
 
@@ -724,6 +731,12 @@ long do_memory_op(unsigned long cmd, XEN
     {
         struct xen_add_to_physmap xatp;
 
+        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for faked input. */
+        if ( start_extent != (typeof(xatp.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
@@ -738,18 +751,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap(d, &xatp);
+        rc = xenmem_add_to_physmap(d, &xatp, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatp, 1) )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc > 0 )
+            rc = hypercall_create_continuation(
+                     __HYPERVISOR_memory_op, "lh",
+                     op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

[PATCH v2 3/4] move XENMEM_add_to_physmap_range handling framework to common code

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 6303 bytes --]

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

This further eliminates the erroneous bailing from
xenmem_add_to_physmap_range() if xenmem_add_to_physmap_one() fails.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: Restore restriction of XENMAPSPACE_gmfn_range only being supported
    through XENMEM_add_to_physmap.

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1057,103 +1057,10 @@ int xenmem_add_to_physmap_one(
     return rc;
 }
 
-static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
-{
-    int rc;
-
-    while ( xatpr->size > 0 )
-    {
-        xen_ulong_t idx;
-        xen_pfn_t gpfn;
-
-        if ( unlikely(copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( unlikely(copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatpr->space,
-                                       xatpr->foreign_domid,
-                                       idx, gpfn);
-
-        if ( unlikely(copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( rc < 0 )
-            goto out;
-
-        guest_handle_add_offset(xatpr->idxs, 1);
-        guest_handle_add_offset(xatpr->gpfns, 1);
-        guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
-
-        /* Check for continuation if it's not the last interation */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
-        {
-            rc = -EAGAIN;
-            goto out;
-        }
-    }
-
-    rc = 0;
-
-out:
-    return rc;
-
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    int rc;
-
     switch ( op )
     {
-    case XENMEM_add_to_physmap_range:
-    {
-        struct xen_add_to_physmap_range xatpr;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatpr, arg, 1) )
-            return -EFAULT;
-
-        /* This mapspace is redundant for this hypercall */
-        if ( xatpr.space == XENMAPSPACE_gmfn_range )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatpr.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
-
-        rcu_unlock_domain(d);
-
-        if ( rc && copy_to_guest(arg, &xatpr, 1) )
-            rc = -EFAULT;
-
-        if ( rc == -EAGAIN )
-            rc = hypercall_create_continuation(
-                __HYPERVISOR_memory_op, "ih", op, arg);
-
-        return rc;
-    }
     /* XXX: memsharing not working yet */
     case XENMEM_get_sharing_shared_pages:
     case XENMEM_get_sharing_freed_pages:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -595,6 +595,57 @@ static int xenmem_add_to_physmap(struct 
     return rc;
 }
 
+static int xenmem_add_to_physmap_range(struct domain *d,
+                                       struct xen_add_to_physmap_range *xatpr)
+{
+    int rc;
+
+    while ( xatpr->size > 0 )
+    {
+        xen_ulong_t idx;
+        xen_pfn_t gpfn;
+
+        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        rc = xenmem_add_to_physmap_one(d, xatpr->space,
+                                       xatpr->foreign_domid,
+                                       idx, gpfn);
+
+        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        guest_handle_add_offset(xatpr->idxs, 1);
+        guest_handle_add_offset(xatpr->gpfns, 1);
+        guest_handle_add_offset(xatpr->errs, 1);
+        xatpr->size--;
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            goto out;
+        }
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -760,6 +811,48 @@ long do_memory_op(unsigned long cmd, XEN
         return rc;
     }
 
+    case XENMEM_add_to_physmap_range:
+    {
+        struct xen_add_to_physmap_range xatpr;
+        struct domain *d;
+
+        if ( copy_from_guest(&xatpr, arg, 1) ||
+             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
+             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
+             !guest_handle_okay(xatpr.errs, xatpr.size) )
+            return -EFAULT;
+
+        /* This mapspace is unsupported for this hypercall. */
+        if ( xatpr.space == XENMAPSPACE_gmfn_range )
+            return -EOPNOTSUPP;
+
+        d = rcu_lock_domain_by_any_id(xatpr.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap_range(d, &xatpr);
+
+        rcu_unlock_domain(d);
+
+        if ( rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatpr, 1) )
+                rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;



[-- Attachment #2: xatpr-common.patch --]
[-- Type: text/plain, Size: 6369 bytes --]

move XENMEM_add_to_physmap_range handling framework to common code

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

This further eliminates the erroneous bailing from
xenmem_add_to_physmap_range() if xenmem_add_to_physmap_one() fails.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: Restore restriction of XENMAPSPACE_gmfn_range only being supported
    through XENMEM_add_to_physmap.

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1057,103 +1057,10 @@ int xenmem_add_to_physmap_one(
     return rc;
 }
 
-static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
-{
-    int rc;
-
-    while ( xatpr->size > 0 )
-    {
-        xen_ulong_t idx;
-        xen_pfn_t gpfn;
-
-        if ( unlikely(copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( unlikely(copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatpr->space,
-                                       xatpr->foreign_domid,
-                                       idx, gpfn);
-
-        if ( unlikely(copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( rc < 0 )
-            goto out;
-
-        guest_handle_add_offset(xatpr->idxs, 1);
-        guest_handle_add_offset(xatpr->gpfns, 1);
-        guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
-
-        /* Check for continuation if it's not the last interation */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
-        {
-            rc = -EAGAIN;
-            goto out;
-        }
-    }
-
-    rc = 0;
-
-out:
-    return rc;
-
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    int rc;
-
     switch ( op )
     {
-    case XENMEM_add_to_physmap_range:
-    {
-        struct xen_add_to_physmap_range xatpr;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatpr, arg, 1) )
-            return -EFAULT;
-
-        /* This mapspace is redundant for this hypercall */
-        if ( xatpr.space == XENMAPSPACE_gmfn_range )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatpr.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
-
-        rcu_unlock_domain(d);
-
-        if ( rc && copy_to_guest(arg, &xatpr, 1) )
-            rc = -EFAULT;
-
-        if ( rc == -EAGAIN )
-            rc = hypercall_create_continuation(
-                __HYPERVISOR_memory_op, "ih", op, arg);
-
-        return rc;
-    }
     /* XXX: memsharing not working yet */
     case XENMEM_get_sharing_shared_pages:
     case XENMEM_get_sharing_freed_pages:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -595,6 +595,57 @@ static int xenmem_add_to_physmap(struct 
     return rc;
 }
 
+static int xenmem_add_to_physmap_range(struct domain *d,
+                                       struct xen_add_to_physmap_range *xatpr)
+{
+    int rc;
+
+    while ( xatpr->size > 0 )
+    {
+        xen_ulong_t idx;
+        xen_pfn_t gpfn;
+
+        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        rc = xenmem_add_to_physmap_one(d, xatpr->space,
+                                       xatpr->foreign_domid,
+                                       idx, gpfn);
+
+        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        guest_handle_add_offset(xatpr->idxs, 1);
+        guest_handle_add_offset(xatpr->gpfns, 1);
+        guest_handle_add_offset(xatpr->errs, 1);
+        xatpr->size--;
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            goto out;
+        }
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -760,6 +811,48 @@ long do_memory_op(unsigned long cmd, XEN
         return rc;
     }
 
+    case XENMEM_add_to_physmap_range:
+    {
+        struct xen_add_to_physmap_range xatpr;
+        struct domain *d;
+
+        if ( copy_from_guest(&xatpr, arg, 1) ||
+             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
+             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
+             !guest_handle_okay(xatpr.errs, xatpr.size) )
+            return -EFAULT;
+
+        /* This mapspace is unsupported for this hypercall. */
+        if ( xatpr.space == XENMAPSPACE_gmfn_range )
+            return -EOPNOTSUPP;
+
+        d = rcu_lock_domain_by_any_id(xatpr.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap_range(d, &xatpr);
+
+        rcu_unlock_domain(d);
+
+        if ( rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatpr, 1) )
+                rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

[PATCH v2 4/4] fix XENMEM_add_to_physmap_range preemption handling

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 3112 bytes --]

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs (the one OUT one really refers to the memory pointed to by
that handle rather than the handle itself).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -596,11 +596,21 @@ static int xenmem_add_to_physmap(struct 
 }
 
 static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
+                                       struct xen_add_to_physmap_range *xatpr,
+                                       unsigned int start)
 {
+    unsigned int done = 0;
     int rc;
 
-    while ( xatpr->size > 0 )
+    if ( xatpr->size < start )
+        return -EILSEQ;
+
+    guest_handle_add_offset(xatpr->idxs, start);
+    guest_handle_add_offset(xatpr->gpfns, start);
+    guest_handle_add_offset(xatpr->errs, start);
+    xatpr->size -= start;
+
+    while ( xatpr->size > done )
     {
         xen_ulong_t idx;
         xen_pfn_t gpfn;
@@ -630,12 +640,11 @@ static int xenmem_add_to_physmap_range(s
         guest_handle_add_offset(xatpr->idxs, 1);
         guest_handle_add_offset(xatpr->gpfns, 1);
         guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        if ( xatpr->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             goto out;
         }
     }
@@ -816,6 +825,13 @@ long do_memory_op(unsigned long cmd, XEN
         struct xen_add_to_physmap_range xatpr;
         struct domain *d;
 
+        BUILD_BUG_ON((typeof(xatpr.size))-1 >
+                     (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for faked input. */
+        if ( start_extent != (typeof(xatpr.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatpr, arg, 1) ||
              !guest_handle_okay(xatpr.idxs, xatpr.size) ||
              !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
@@ -837,18 +853,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
+        rc = xenmem_add_to_physmap_range(d, &xatpr, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatpr, 1) )
-                rc = hypercall_create_continuation(
-                    __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( rc > 0 )
+            rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "lh",
+                    op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }




[-- Attachment #2: xatpr-preemption.patch --]
[-- Type: text/plain, Size: 3161 bytes --]

fix XENMEM_add_to_physmap_range preemption handling

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs (the one OUT one really refers to the memory pointed to by
that handle rather than the handle itself).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -596,11 +596,21 @@ static int xenmem_add_to_physmap(struct 
 }
 
 static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
+                                       struct xen_add_to_physmap_range *xatpr,
+                                       unsigned int start)
 {
+    unsigned int done = 0;
     int rc;
 
-    while ( xatpr->size > 0 )
+    if ( xatpr->size < start )
+        return -EILSEQ;
+
+    guest_handle_add_offset(xatpr->idxs, start);
+    guest_handle_add_offset(xatpr->gpfns, start);
+    guest_handle_add_offset(xatpr->errs, start);
+    xatpr->size -= start;
+
+    while ( xatpr->size > done )
     {
         xen_ulong_t idx;
         xen_pfn_t gpfn;
@@ -630,12 +640,11 @@ static int xenmem_add_to_physmap_range(s
         guest_handle_add_offset(xatpr->idxs, 1);
         guest_handle_add_offset(xatpr->gpfns, 1);
         guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        if ( xatpr->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             goto out;
         }
     }
@@ -816,6 +825,13 @@ long do_memory_op(unsigned long cmd, XEN
         struct xen_add_to_physmap_range xatpr;
         struct domain *d;
 
+        BUILD_BUG_ON((typeof(xatpr.size))-1 >
+                     (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for faked input. */
+        if ( start_extent != (typeof(xatpr.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatpr, arg, 1) ||
              !guest_handle_okay(xatpr.idxs, xatpr.size) ||
              !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
@@ -837,18 +853,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
+        rc = xenmem_add_to_physmap_range(d, &xatpr, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatpr, 1) )
-                rc = hypercall_create_continuation(
-                    __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( rc > 0 )
+            rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "lh",
+                    op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

[PATCH v3 0/5] fix preemption handling for XENMEM_add_to_physmap_range{, _range}

[Jan Beulich]

The hypervisor isn't supposed to use the input structures for
storing continuation information - only fields explicitly used as
hypercall outputs should ever be updated.

Obviously this implies an ABI change, but since the previous
behavior was not intended to be that way I don't think we should
stick to the old behavior.

There's one caveat though - with the previous model, the caller
could - upon failure - use the updated structure to find out how
by progress was made. However, that wasn't intended afaict,
largely supported by this information depending on hypervisor
internals (i.e. the caller would have to know the order of request 
processing and the meaning of the respective size fields, which
aren't simply saying "this much was processed").

Consequently, as a follow-up we may want to consider making
explicit (and straight forward) this progress indication on error.

1: move XENMEM_add_to_physmap handling framework to common code
2: fix XENMEM_add_to_physmap preemption handling
3: move XENMEM_add_to_physmap_range handling framework to common code
4: fix XENMEM_add_to_physmap_range preemption handling
5: rename XENMEM_add_to_physmap_{range => batch}

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v3: Retain restriction of XENMAPSPACE_gmfn_foreign not being
    possible via XENMEM_add_to_physmap (patch 1). Apart from
    patch 5 being new, other patches unchanged .
v2: Apart from the removal of a bogus ASSERT() as requested
    by Tim, only a couple minor/cosmetic changes (see individual
    patches), hence I'm retaining the tags that were already
    given for v1.

[PATCH v3 1/5] move XENMEM_add_to_physmap handling framework to common code

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 14415 bytes --]

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v3: Restriction of XENMAPSPACE_gmfn_foreign only being possible via
    XENMEM_add_to_physmap_range no longer being dropped.

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -968,7 +968,7 @@ void share_xen_page_with_privileged_gues
     share_xen_page_with_guest(page, dom_xen, readonly);
 }
 
-static int xenmem_add_to_physmap_one(
+int xenmem_add_to_physmap_one(
     struct domain *d,
     uint16_t space,
     domid_t foreign_domid,
@@ -1118,37 +1118,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        /* Foreign mapping is only supported by add_to_physmap_range */
-        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatp.space, DOMID_INVALID,
-                                       xatp.idx, xatp.gpfn);
-
-        rcu_unlock_domain(d);
-
-        return rc;
-    }
-
     case XENMEM_add_to_physmap_range:
     {
         struct xen_add_to_physmap_range xatpr;
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4520,20 +4520,23 @@ static int handle_iomem_range(unsigned l
     return 0;
 }
 
-static int xenmem_add_to_physmap_once(
+int xenmem_add_to_physmap_one(
     struct domain *d,
-    const struct xen_add_to_physmap *xatp)
+    uint16_t space,
+    domid_t foreign_domid,
+    unsigned long idx,
+    xen_pfn_t gpfn)
 {
     struct page_info *page = NULL;
     unsigned long gfn = 0; /* gcc ... */
-    unsigned long prev_mfn, mfn = 0, gpfn, idx;
+    unsigned long prev_mfn, mfn = 0, old_gpfn;
     int rc;
     p2m_type_t p2mt;
 
-    switch ( xatp->space )
+    switch ( space )
     {
         case XENMAPSPACE_shared_info:
-            if ( xatp->idx == 0 )
+            if ( idx == 0 )
                 mfn = virt_to_mfn(d->shared_info);
             break;
         case XENMAPSPACE_grant_table:
@@ -4542,9 +4545,8 @@ static int xenmem_add_to_physmap_once(
             if ( d->grant_table->gt_version == 0 )
                 d->grant_table->gt_version = 1;
 
-            idx = xatp->idx;
             if ( d->grant_table->gt_version == 2 &&
-                 (xatp->idx & XENMAPIDX_grant_table_status) )
+                 (idx & XENMAPIDX_grant_table_status) )
             {
                 idx &= ~XENMAPIDX_grant_table_status;
                 if ( idx < nr_status_frames(d->grant_table) )
@@ -4566,9 +4568,9 @@ static int xenmem_add_to_physmap_once(
         case XENMAPSPACE_gmfn:
         {
             p2m_type_t p2mt;
-            gfn = xatp->idx;
 
-            idx = mfn_x(get_gfn_unshare(d, xatp->idx, &p2mt));
+            gfn = idx;
+            idx = mfn_x(get_gfn_unshare(d, idx, &p2mt));
             /* If the page is still shared, exit early */
             if ( p2m_is_shared(p2mt) )
             {
@@ -4589,41 +4591,38 @@ static int xenmem_add_to_physmap_once(
     {
         if ( page )
             put_page(page);
-        if ( xatp->space == XENMAPSPACE_gmfn ||
-             xatp->space == XENMAPSPACE_gmfn_range )
+        if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
             put_gfn(d, gfn);
         return -EINVAL;
     }
 
     /* Remove previously mapped page if it was present. */
-    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
+    prev_mfn = mfn_x(get_gfn(d, gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
     {
         if ( is_xen_heap_mfn(prev_mfn) )
             /* Xen heap frames are simply unhooked from this phys slot. */
-            guest_physmap_remove_page(d, xatp->gpfn, prev_mfn, PAGE_ORDER_4K);
+            guest_physmap_remove_page(d, gpfn, prev_mfn, PAGE_ORDER_4K);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */
-            guest_remove_page(d, xatp->gpfn);
+            guest_remove_page(d, gpfn);
     }
     /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */
-    put_gfn(d, xatp->gpfn);
+    put_gfn(d, gpfn);
 
     /* Unmap from old location, if any. */
-    gpfn = get_gpfn_from_mfn(mfn);
-    ASSERT( gpfn != SHARED_M2P_ENTRY );
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
-        ASSERT( gpfn == gfn );
-    if ( gpfn != INVALID_M2P_ENTRY )
-        guest_physmap_remove_page(d, gpfn, mfn, PAGE_ORDER_4K);
+    old_gpfn = get_gpfn_from_mfn(mfn);
+    ASSERT( old_gpfn != SHARED_M2P_ENTRY );
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
+        ASSERT( old_gpfn == gfn );
+    if ( old_gpfn != INVALID_M2P_ENTRY )
+        guest_physmap_remove_page(d, old_gpfn, mfn, PAGE_ORDER_4K);
 
     /* Map at new location. */
-    rc = guest_physmap_add_page(d, xatp->gpfn, mfn, PAGE_ORDER_4K);
+    rc = guest_physmap_add_page(d, gpfn, mfn, PAGE_ORDER_4K);
 
     /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
         put_gfn(d, gfn);
 
     if ( page )
@@ -4632,90 +4631,12 @@ static int xenmem_add_to_physmap_once(
     return rc;
 }
 
-static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
-{
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
-
-    if ( xatp->space == XENMAPSPACE_gmfn_range )
-    {
-        if ( need_iommu(d) )
-            this_cpu(iommu_dont_flush_iotlb) = 1;
-
-        start_xatp = *xatp;
-        while ( xatp->size > 0 )
-        {
-            rc = xenmem_add_to_physmap_once(d, xatp);
-            if ( rc < 0 )
-                break;
-
-            xatp->idx++;
-            xatp->gpfn++;
-            xatp->size--;
-
-            /* Check for continuation if it's not the last interation */
-            if ( xatp->size > 0 && hypercall_preempt_check() )
-            {
-                rc = -EAGAIN;
-                break;
-            }
-        }
-
-        if ( need_iommu(d) )
-        {
-            this_cpu(iommu_dont_flush_iotlb) = 0;
-            iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-            iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
-        }
-
-        return rc;
-    }
-
-    return xenmem_add_to_physmap_once(d, xatp);
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     int rc;
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
-        {
-            rcu_unlock_domain(d);
-            return -EPERM;
-        }
-
-        rc = xenmem_add_to_physmap(d, &xatp);
-
-        rcu_unlock_domain(d);
-
-        if ( xatp.space == XENMAPSPACE_gmfn_range )
-        {
-            if ( rc && __copy_to_guest(arg, &xatp, 1) )
-                rc = -EFAULT;
-
-            if ( rc == -EAGAIN )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-        }
-
-        return rc;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct xen_foreign_memory_map fmap;
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -55,34 +55,6 @@ int compat_arch_memory_op(int op, XEN_GU
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct compat_add_to_physmap cmp;
-        struct xen_add_to_physmap *nat = COMPAT_ARG_XLAT_VIRT_BASE;
-
-        if ( copy_from_guest(&cmp, arg, 1) )
-            return -EFAULT;
-
-        XLAT_add_to_physmap(nat, &cmp);
-        rc = arch_memory_op(op, guest_handle_from_ptr(nat, void));
-
-        if ( !rc || cmp.space != XENMAPSPACE_gmfn_range )
-            break;
-
-        XLAT_add_to_physmap(&cmp, nat);
-        if ( __copy_to_guest(arg, &cmp, 1) )
-        {
-            if ( rc == __HYPERVISOR_memory_op )
-                hypercall_cancel_continuation();
-            return -EFAULT;
-        }
-
-        if ( rc == __HYPERVISOR_memory_op )
-            hypercall_xlat_continuation(NULL, 0x2, nat, arg);
-
-        break;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct compat_foreign_memory_map cmp;
--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -26,11 +26,13 @@ int compat_memory_op(unsigned int cmd, X
             XEN_GUEST_HANDLE_PARAM(void) hnd;
             struct xen_memory_reservation *rsrv;
             struct xen_memory_exchange *xchg;
+            struct xen_add_to_physmap *atp;
             struct xen_remove_from_physmap *xrfp;
         } nat;
         union {
             struct compat_memory_reservation rsrv;
             struct compat_memory_exchange xchg;
+            struct compat_add_to_physmap atp;
         } cmp;
 
         set_xen_guest_handle(nat.hnd, COMPAT_ARG_XLAT_VIRT_BASE);
@@ -187,6 +189,14 @@ int compat_memory_op(unsigned int cmd, X
             nat.hnd = compat;
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( copy_from_guest(&cmp.atp, compat, 1) )
+                return -EFAULT;
+
+            XLAT_add_to_physmap(nat.atp, &cmp.atp);
+
+            break;
+
         case XENMEM_remove_from_physmap:
         {
             struct compat_remove_from_physmap cmp;
@@ -315,6 +325,16 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_remove_from_physmap:
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
+                break;
+
+            XLAT_add_to_physmap(&cmp.atp, nat.atp);
+            if ( __copy_to_guest(compat, &cmp.atp, 1) )
+                rc = -EFAULT;
+
+            break;
+
         default:
             domain_crash(current->domain);
             split = 0;
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -542,6 +542,53 @@ static long memory_exchange(XEN_GUEST_HA
     return rc;
 }
 
+static int xenmem_add_to_physmap(struct domain *d,
+                                 struct xen_add_to_physmap *xatp)
+{
+    struct xen_add_to_physmap start_xatp;
+    int rc = 0;
+
+    if ( xatp->space != XENMAPSPACE_gmfn_range )
+        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                         xatp->idx, xatp->gpfn);
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+        this_cpu(iommu_dont_flush_iotlb) = 1;
+#endif
+
+    start_xatp = *xatp;
+    while ( xatp->size > 0 )
+    {
+        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                       xatp->idx, xatp->gpfn);
+        if ( rc < 0 )
+            break;
+
+        xatp->idx++;
+        xatp->gpfn++;
+        xatp->size--;
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( xatp->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            break;
+        }
+    }
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+    {
+        this_cpu(iommu_dont_flush_iotlb) = 0;
+        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+    }
+#endif
+
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -673,6 +720,44 @@ long do_memory_op(unsigned long cmd, XEN
 
         break;
 
+    case XENMEM_add_to_physmap:
+    {
+        struct xen_add_to_physmap xatp;
+
+        if ( copy_from_guest(&xatp, arg, 1) )
+            return -EFAULT;
+
+        /* Foreign mapping is only possible via add_to_physmap_range. */
+        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
+            return -ENOSYS;
+
+        d = rcu_lock_domain_by_any_id(xatp.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap(d, &xatp);
+
+        rcu_unlock_domain(d);
+
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatp, 1) )
+                rc = hypercall_create_continuation(
+                        __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -356,6 +356,10 @@ static inline unsigned int get_order_fro
 
 void scrub_one_page(struct page_info *);
 
+int xenmem_add_to_physmap_one(struct domain *d, uint16_t space,
+                              domid_t foreign_domid,
+                              unsigned long idx, xen_pfn_t gpfn);
+
 /* Returns 1 on success, 0 on error, negative if the ring
  * for event propagation is full in the presence of paging */
 int guest_remove_page(struct domain *d, unsigned long gmfn);



[-- Attachment #2: xatp-common.patch --]
[-- Type: text/plain, Size: 14475 bytes --]

move XENMEM_add_to_physmap handling framework to common code

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v3: Restriction of XENMAPSPACE_gmfn_foreign only being possible via
    XENMEM_add_to_physmap_range no longer being dropped.

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -968,7 +968,7 @@ void share_xen_page_with_privileged_gues
     share_xen_page_with_guest(page, dom_xen, readonly);
 }
 
-static int xenmem_add_to_physmap_one(
+int xenmem_add_to_physmap_one(
     struct domain *d,
     uint16_t space,
     domid_t foreign_domid,
@@ -1118,37 +1118,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        /* Foreign mapping is only supported by add_to_physmap_range */
-        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatp.space, DOMID_INVALID,
-                                       xatp.idx, xatp.gpfn);
-
-        rcu_unlock_domain(d);
-
-        return rc;
-    }
-
     case XENMEM_add_to_physmap_range:
     {
         struct xen_add_to_physmap_range xatpr;
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4520,20 +4520,23 @@ static int handle_iomem_range(unsigned l
     return 0;
 }
 
-static int xenmem_add_to_physmap_once(
+int xenmem_add_to_physmap_one(
     struct domain *d,
-    const struct xen_add_to_physmap *xatp)
+    uint16_t space,
+    domid_t foreign_domid,
+    unsigned long idx,
+    xen_pfn_t gpfn)
 {
     struct page_info *page = NULL;
     unsigned long gfn = 0; /* gcc ... */
-    unsigned long prev_mfn, mfn = 0, gpfn, idx;
+    unsigned long prev_mfn, mfn = 0, old_gpfn;
     int rc;
     p2m_type_t p2mt;
 
-    switch ( xatp->space )
+    switch ( space )
     {
         case XENMAPSPACE_shared_info:
-            if ( xatp->idx == 0 )
+            if ( idx == 0 )
                 mfn = virt_to_mfn(d->shared_info);
             break;
         case XENMAPSPACE_grant_table:
@@ -4542,9 +4545,8 @@ static int xenmem_add_to_physmap_once(
             if ( d->grant_table->gt_version == 0 )
                 d->grant_table->gt_version = 1;
 
-            idx = xatp->idx;
             if ( d->grant_table->gt_version == 2 &&
-                 (xatp->idx & XENMAPIDX_grant_table_status) )
+                 (idx & XENMAPIDX_grant_table_status) )
             {
                 idx &= ~XENMAPIDX_grant_table_status;
                 if ( idx < nr_status_frames(d->grant_table) )
@@ -4566,9 +4568,9 @@ static int xenmem_add_to_physmap_once(
         case XENMAPSPACE_gmfn:
         {
             p2m_type_t p2mt;
-            gfn = xatp->idx;
 
-            idx = mfn_x(get_gfn_unshare(d, xatp->idx, &p2mt));
+            gfn = idx;
+            idx = mfn_x(get_gfn_unshare(d, idx, &p2mt));
             /* If the page is still shared, exit early */
             if ( p2m_is_shared(p2mt) )
             {
@@ -4589,41 +4591,38 @@ static int xenmem_add_to_physmap_once(
     {
         if ( page )
             put_page(page);
-        if ( xatp->space == XENMAPSPACE_gmfn ||
-             xatp->space == XENMAPSPACE_gmfn_range )
+        if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
             put_gfn(d, gfn);
         return -EINVAL;
     }
 
     /* Remove previously mapped page if it was present. */
-    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
+    prev_mfn = mfn_x(get_gfn(d, gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
     {
         if ( is_xen_heap_mfn(prev_mfn) )
             /* Xen heap frames are simply unhooked from this phys slot. */
-            guest_physmap_remove_page(d, xatp->gpfn, prev_mfn, PAGE_ORDER_4K);
+            guest_physmap_remove_page(d, gpfn, prev_mfn, PAGE_ORDER_4K);
         else
             /* Normal domain memory is freed, to avoid leaking memory. */
-            guest_remove_page(d, xatp->gpfn);
+            guest_remove_page(d, gpfn);
     }
     /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */
-    put_gfn(d, xatp->gpfn);
+    put_gfn(d, gpfn);
 
     /* Unmap from old location, if any. */
-    gpfn = get_gpfn_from_mfn(mfn);
-    ASSERT( gpfn != SHARED_M2P_ENTRY );
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
-        ASSERT( gpfn == gfn );
-    if ( gpfn != INVALID_M2P_ENTRY )
-        guest_physmap_remove_page(d, gpfn, mfn, PAGE_ORDER_4K);
+    old_gpfn = get_gpfn_from_mfn(mfn);
+    ASSERT( old_gpfn != SHARED_M2P_ENTRY );
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
+        ASSERT( old_gpfn == gfn );
+    if ( old_gpfn != INVALID_M2P_ENTRY )
+        guest_physmap_remove_page(d, old_gpfn, mfn, PAGE_ORDER_4K);
 
     /* Map at new location. */
-    rc = guest_physmap_add_page(d, xatp->gpfn, mfn, PAGE_ORDER_4K);
+    rc = guest_physmap_add_page(d, gpfn, mfn, PAGE_ORDER_4K);
 
     /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */
-    if ( xatp->space == XENMAPSPACE_gmfn ||
-         xatp->space == XENMAPSPACE_gmfn_range )
+    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
         put_gfn(d, gfn);
 
     if ( page )
@@ -4632,90 +4631,12 @@ static int xenmem_add_to_physmap_once(
     return rc;
 }
 
-static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
-{
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
-
-    if ( xatp->space == XENMAPSPACE_gmfn_range )
-    {
-        if ( need_iommu(d) )
-            this_cpu(iommu_dont_flush_iotlb) = 1;
-
-        start_xatp = *xatp;
-        while ( xatp->size > 0 )
-        {
-            rc = xenmem_add_to_physmap_once(d, xatp);
-            if ( rc < 0 )
-                break;
-
-            xatp->idx++;
-            xatp->gpfn++;
-            xatp->size--;
-
-            /* Check for continuation if it's not the last interation */
-            if ( xatp->size > 0 && hypercall_preempt_check() )
-            {
-                rc = -EAGAIN;
-                break;
-            }
-        }
-
-        if ( need_iommu(d) )
-        {
-            this_cpu(iommu_dont_flush_iotlb) = 0;
-            iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-            iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
-        }
-
-        return rc;
-    }
-
-    return xenmem_add_to_physmap_once(d, xatp);
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     int rc;
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct xen_add_to_physmap xatp;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatp, arg, 1) )
-            return -EFAULT;
-
-        d = rcu_lock_domain_by_any_id(xatp.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
-        {
-            rcu_unlock_domain(d);
-            return -EPERM;
-        }
-
-        rc = xenmem_add_to_physmap(d, &xatp);
-
-        rcu_unlock_domain(d);
-
-        if ( xatp.space == XENMAPSPACE_gmfn_range )
-        {
-            if ( rc && __copy_to_guest(arg, &xatp, 1) )
-                rc = -EFAULT;
-
-            if ( rc == -EAGAIN )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-        }
-
-        return rc;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct xen_foreign_memory_map fmap;
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -55,34 +55,6 @@ int compat_arch_memory_op(int op, XEN_GU
 
     switch ( op )
     {
-    case XENMEM_add_to_physmap:
-    {
-        struct compat_add_to_physmap cmp;
-        struct xen_add_to_physmap *nat = COMPAT_ARG_XLAT_VIRT_BASE;
-
-        if ( copy_from_guest(&cmp, arg, 1) )
-            return -EFAULT;
-
-        XLAT_add_to_physmap(nat, &cmp);
-        rc = arch_memory_op(op, guest_handle_from_ptr(nat, void));
-
-        if ( !rc || cmp.space != XENMAPSPACE_gmfn_range )
-            break;
-
-        XLAT_add_to_physmap(&cmp, nat);
-        if ( __copy_to_guest(arg, &cmp, 1) )
-        {
-            if ( rc == __HYPERVISOR_memory_op )
-                hypercall_cancel_continuation();
-            return -EFAULT;
-        }
-
-        if ( rc == __HYPERVISOR_memory_op )
-            hypercall_xlat_continuation(NULL, 0x2, nat, arg);
-
-        break;
-    }
-
     case XENMEM_set_memory_map:
     {
         struct compat_foreign_memory_map cmp;
--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -26,11 +26,13 @@ int compat_memory_op(unsigned int cmd, X
             XEN_GUEST_HANDLE_PARAM(void) hnd;
             struct xen_memory_reservation *rsrv;
             struct xen_memory_exchange *xchg;
+            struct xen_add_to_physmap *atp;
             struct xen_remove_from_physmap *xrfp;
         } nat;
         union {
             struct compat_memory_reservation rsrv;
             struct compat_memory_exchange xchg;
+            struct compat_add_to_physmap atp;
         } cmp;
 
         set_xen_guest_handle(nat.hnd, COMPAT_ARG_XLAT_VIRT_BASE);
@@ -187,6 +189,14 @@ int compat_memory_op(unsigned int cmd, X
             nat.hnd = compat;
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( copy_from_guest(&cmp.atp, compat, 1) )
+                return -EFAULT;
+
+            XLAT_add_to_physmap(nat.atp, &cmp.atp);
+
+            break;
+
         case XENMEM_remove_from_physmap:
         {
             struct compat_remove_from_physmap cmp;
@@ -315,6 +325,16 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_remove_from_physmap:
             break;
 
+        case XENMEM_add_to_physmap:
+            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
+                break;
+
+            XLAT_add_to_physmap(&cmp.atp, nat.atp);
+            if ( __copy_to_guest(compat, &cmp.atp, 1) )
+                rc = -EFAULT;
+
+            break;
+
         default:
             domain_crash(current->domain);
             split = 0;
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -542,6 +542,53 @@ static long memory_exchange(XEN_GUEST_HA
     return rc;
 }
 
+static int xenmem_add_to_physmap(struct domain *d,
+                                 struct xen_add_to_physmap *xatp)
+{
+    struct xen_add_to_physmap start_xatp;
+    int rc = 0;
+
+    if ( xatp->space != XENMAPSPACE_gmfn_range )
+        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                         xatp->idx, xatp->gpfn);
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+        this_cpu(iommu_dont_flush_iotlb) = 1;
+#endif
+
+    start_xatp = *xatp;
+    while ( xatp->size > 0 )
+    {
+        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
+                                       xatp->idx, xatp->gpfn);
+        if ( rc < 0 )
+            break;
+
+        xatp->idx++;
+        xatp->gpfn++;
+        xatp->size--;
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( xatp->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            break;
+        }
+    }
+
+#ifdef HAS_PASSTHROUGH
+    if ( need_iommu(d) )
+    {
+        this_cpu(iommu_dont_flush_iotlb) = 0;
+        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+    }
+#endif
+
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -673,6 +720,44 @@ long do_memory_op(unsigned long cmd, XEN
 
         break;
 
+    case XENMEM_add_to_physmap:
+    {
+        struct xen_add_to_physmap xatp;
+
+        if ( copy_from_guest(&xatp, arg, 1) )
+            return -EFAULT;
+
+        /* Foreign mapping is only possible via add_to_physmap_range. */
+        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
+            return -ENOSYS;
+
+        d = rcu_lock_domain_by_any_id(xatp.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap(d, &xatp);
+
+        rcu_unlock_domain(d);
+
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatp, 1) )
+                rc = hypercall_create_continuation(
+                        __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -356,6 +356,10 @@ static inline unsigned int get_order_fro
 
 void scrub_one_page(struct page_info *);
 
+int xenmem_add_to_physmap_one(struct domain *d, uint16_t space,
+                              domid_t foreign_domid,
+                              unsigned long idx, xen_pfn_t gpfn);
+
 /* Returns 1 on success, 0 on error, negative if the ring
  * for event propagation is full in the presence of paging */
 int guest_remove_page(struct domain *d, unsigned long gmfn);

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

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Re: [PATCH v3 1/5] move XENMEM_add_to_physmap handling framework to common code

[Ian Campbell]

On Fri, 2013-12-20 at 10:41 +0000, Jan Beulich wrote:
> There's really nothing really architecture specific here; the
> architecture specific handling is limited to
> xenmem_add_to_physmap_one().
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Tim Deegan <tim@xen.org>
> Acked-by: Keir Fraser <keir@xen.org>

Acked-by: Ian Campbell <ian.campbell@citrix.com>
(nb: I didn't look at the x86 bits at all...)

> ---
> v3: Restriction of XENMAPSPACE_gmfn_foreign only being possible via
>     XENMEM_add_to_physmap_range no longer being dropped.

Thanks.

Ian.

Re: [PATCH v3 1/5] move XENMEM_add_to_physmap handling framework to common code

[Andrew Cooper]

[-- Attachment #1.1: Type: text/plain, Size: 15181 bytes --]

On 20/12/13 10:41, Jan Beulich wrote:
> There's really nothing really architecture specific here; the
> architecture specific handling is limited to
> xenmem_add_to_physmap_one().
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Tim Deegan <tim@xen.org>
> Acked-by: Keir Fraser <keir@xen.org>
> ---
> v3: Restriction of XENMAPSPACE_gmfn_foreign only being possible via
>     XENMEM_add_to_physmap_range no longer being dropped.
>
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -968,7 +968,7 @@ void share_xen_page_with_privileged_gues
>      share_xen_page_with_guest(page, dom_xen, readonly);
>  }
>  
> -static int xenmem_add_to_physmap_one(
> +int xenmem_add_to_physmap_one(
>      struct domain *d,
>      uint16_t space,
>      domid_t foreign_domid,
> @@ -1118,37 +1118,6 @@ long arch_memory_op(int op, XEN_GUEST_HA
>  
>      switch ( op )
>      {
> -    case XENMEM_add_to_physmap:
> -    {
> -        struct xen_add_to_physmap xatp;
> -        struct domain *d;
> -
> -        if ( copy_from_guest(&xatp, arg, 1) )
> -            return -EFAULT;
> -
> -        /* Foreign mapping is only supported by add_to_physmap_range */
> -        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
> -            return -EINVAL;
> -
> -        d = rcu_lock_domain_by_any_id(xatp.domid);
> -        if ( d == NULL )
> -            return -ESRCH;
> -
> -        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
> -        if ( rc )
> -        {
> -            rcu_unlock_domain(d);
> -            return rc;
> -        }
> -
> -        rc = xenmem_add_to_physmap_one(d, xatp.space, DOMID_INVALID,
> -                                       xatp.idx, xatp.gpfn);
> -
> -        rcu_unlock_domain(d);
> -
> -        return rc;
> -    }
> -
>      case XENMEM_add_to_physmap_range:
>      {
>          struct xen_add_to_physmap_range xatpr;
> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -4520,20 +4520,23 @@ static int handle_iomem_range(unsigned l
>      return 0;
>  }
>  
> -static int xenmem_add_to_physmap_once(
> +int xenmem_add_to_physmap_one(
>      struct domain *d,
> -    const struct xen_add_to_physmap *xatp)
> +    uint16_t space,
> +    domid_t foreign_domid,
> +    unsigned long idx,
> +    xen_pfn_t gpfn)
>  {
>      struct page_info *page = NULL;
>      unsigned long gfn = 0; /* gcc ... */
> -    unsigned long prev_mfn, mfn = 0, gpfn, idx;
> +    unsigned long prev_mfn, mfn = 0, old_gpfn;
>      int rc;
>      p2m_type_t p2mt;
>  
> -    switch ( xatp->space )
> +    switch ( space )
>      {
>          case XENMAPSPACE_shared_info:
> -            if ( xatp->idx == 0 )
> +            if ( idx == 0 )
>                  mfn = virt_to_mfn(d->shared_info);
>              break;
>          case XENMAPSPACE_grant_table:
> @@ -4542,9 +4545,8 @@ static int xenmem_add_to_physmap_once(
>              if ( d->grant_table->gt_version == 0 )
>                  d->grant_table->gt_version = 1;
>  
> -            idx = xatp->idx;
>              if ( d->grant_table->gt_version == 2 &&
> -                 (xatp->idx & XENMAPIDX_grant_table_status) )
> +                 (idx & XENMAPIDX_grant_table_status) )
>              {
>                  idx &= ~XENMAPIDX_grant_table_status;
>                  if ( idx < nr_status_frames(d->grant_table) )
> @@ -4566,9 +4568,9 @@ static int xenmem_add_to_physmap_once(
>          case XENMAPSPACE_gmfn:
>          {
>              p2m_type_t p2mt;
> -            gfn = xatp->idx;
>  
> -            idx = mfn_x(get_gfn_unshare(d, xatp->idx, &p2mt));
> +            gfn = idx;
> +            idx = mfn_x(get_gfn_unshare(d, idx, &p2mt));
>              /* If the page is still shared, exit early */
>              if ( p2m_is_shared(p2mt) )
>              {
> @@ -4589,41 +4591,38 @@ static int xenmem_add_to_physmap_once(
>      {
>          if ( page )
>              put_page(page);
> -        if ( xatp->space == XENMAPSPACE_gmfn ||
> -             xatp->space == XENMAPSPACE_gmfn_range )
> +        if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
>              put_gfn(d, gfn);
>          return -EINVAL;
>      }
>  
>      /* Remove previously mapped page if it was present. */
> -    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
> +    prev_mfn = mfn_x(get_gfn(d, gpfn, &p2mt));
>      if ( mfn_valid(prev_mfn) )
>      {
>          if ( is_xen_heap_mfn(prev_mfn) )
>              /* Xen heap frames are simply unhooked from this phys slot. */
> -            guest_physmap_remove_page(d, xatp->gpfn, prev_mfn, PAGE_ORDER_4K);
> +            guest_physmap_remove_page(d, gpfn, prev_mfn, PAGE_ORDER_4K);
>          else
>              /* Normal domain memory is freed, to avoid leaking memory. */
> -            guest_remove_page(d, xatp->gpfn);
> +            guest_remove_page(d, gpfn);
>      }
>      /* In the XENMAPSPACE_gmfn case we still hold a ref on the old page. */
> -    put_gfn(d, xatp->gpfn);
> +    put_gfn(d, gpfn);
>  
>      /* Unmap from old location, if any. */
> -    gpfn = get_gpfn_from_mfn(mfn);
> -    ASSERT( gpfn != SHARED_M2P_ENTRY );
> -    if ( xatp->space == XENMAPSPACE_gmfn ||
> -         xatp->space == XENMAPSPACE_gmfn_range )
> -        ASSERT( gpfn == gfn );
> -    if ( gpfn != INVALID_M2P_ENTRY )
> -        guest_physmap_remove_page(d, gpfn, mfn, PAGE_ORDER_4K);
> +    old_gpfn = get_gpfn_from_mfn(mfn);
> +    ASSERT( old_gpfn != SHARED_M2P_ENTRY );
> +    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
> +        ASSERT( old_gpfn == gfn );
> +    if ( old_gpfn != INVALID_M2P_ENTRY )
> +        guest_physmap_remove_page(d, old_gpfn, mfn, PAGE_ORDER_4K);
>  
>      /* Map at new location. */
> -    rc = guest_physmap_add_page(d, xatp->gpfn, mfn, PAGE_ORDER_4K);
> +    rc = guest_physmap_add_page(d, gpfn, mfn, PAGE_ORDER_4K);
>  
>      /* In the XENMAPSPACE_gmfn, we took a ref of the gfn at the top */
> -    if ( xatp->space == XENMAPSPACE_gmfn ||
> -         xatp->space == XENMAPSPACE_gmfn_range )
> +    if ( space == XENMAPSPACE_gmfn || space == XENMAPSPACE_gmfn_range )
>          put_gfn(d, gfn);
>  
>      if ( page )
> @@ -4632,90 +4631,12 @@ static int xenmem_add_to_physmap_once(
>      return rc;
>  }
>  
> -static int xenmem_add_to_physmap(struct domain *d,
> -                                 struct xen_add_to_physmap *xatp)
> -{
> -    struct xen_add_to_physmap start_xatp;
> -    int rc = 0;
> -
> -    if ( xatp->space == XENMAPSPACE_gmfn_range )
> -    {
> -        if ( need_iommu(d) )
> -            this_cpu(iommu_dont_flush_iotlb) = 1;
> -
> -        start_xatp = *xatp;
> -        while ( xatp->size > 0 )
> -        {
> -            rc = xenmem_add_to_physmap_once(d, xatp);
> -            if ( rc < 0 )
> -                break;
> -
> -            xatp->idx++;
> -            xatp->gpfn++;
> -            xatp->size--;
> -
> -            /* Check for continuation if it's not the last interation */
> -            if ( xatp->size > 0 && hypercall_preempt_check() )
> -            {
> -                rc = -EAGAIN;
> -                break;
> -            }
> -        }
> -
> -        if ( need_iommu(d) )
> -        {
> -            this_cpu(iommu_dont_flush_iotlb) = 0;
> -            iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
> -            iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
> -        }
> -
> -        return rc;
> -    }
> -
> -    return xenmem_add_to_physmap_once(d, xatp);
> -}
> -
>  long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
>  {
>      int rc;
>  
>      switch ( op )
>      {
> -    case XENMEM_add_to_physmap:
> -    {
> -        struct xen_add_to_physmap xatp;
> -        struct domain *d;
> -
> -        if ( copy_from_guest(&xatp, arg, 1) )
> -            return -EFAULT;
> -
> -        d = rcu_lock_domain_by_any_id(xatp.domid);
> -        if ( d == NULL )
> -            return -ESRCH;
> -
> -        if ( xsm_add_to_physmap(XSM_TARGET, current->domain, d) )
> -        {
> -            rcu_unlock_domain(d);
> -            return -EPERM;
> -        }
> -
> -        rc = xenmem_add_to_physmap(d, &xatp);
> -
> -        rcu_unlock_domain(d);
> -
> -        if ( xatp.space == XENMAPSPACE_gmfn_range )
> -        {
> -            if ( rc && __copy_to_guest(arg, &xatp, 1) )
> -                rc = -EFAULT;
> -
> -            if ( rc == -EAGAIN )
> -                rc = hypercall_create_continuation(
> -                        __HYPERVISOR_memory_op, "ih", op, arg);
> -        }
> -
> -        return rc;
> -    }
> -
>      case XENMEM_set_memory_map:
>      {
>          struct xen_foreign_memory_map fmap;
> --- a/xen/arch/x86/x86_64/compat/mm.c
> +++ b/xen/arch/x86/x86_64/compat/mm.c
> @@ -55,34 +55,6 @@ int compat_arch_memory_op(int op, XEN_GU
>  
>      switch ( op )
>      {
> -    case XENMEM_add_to_physmap:
> -    {
> -        struct compat_add_to_physmap cmp;
> -        struct xen_add_to_physmap *nat = COMPAT_ARG_XLAT_VIRT_BASE;
> -
> -        if ( copy_from_guest(&cmp, arg, 1) )
> -            return -EFAULT;
> -
> -        XLAT_add_to_physmap(nat, &cmp);
> -        rc = arch_memory_op(op, guest_handle_from_ptr(nat, void));
> -
> -        if ( !rc || cmp.space != XENMAPSPACE_gmfn_range )
> -            break;
> -
> -        XLAT_add_to_physmap(&cmp, nat);
> -        if ( __copy_to_guest(arg, &cmp, 1) )
> -        {
> -            if ( rc == __HYPERVISOR_memory_op )
> -                hypercall_cancel_continuation();
> -            return -EFAULT;
> -        }
> -
> -        if ( rc == __HYPERVISOR_memory_op )
> -            hypercall_xlat_continuation(NULL, 0x2, nat, arg);
> -
> -        break;
> -    }
> -
>      case XENMEM_set_memory_map:
>      {
>          struct compat_foreign_memory_map cmp;
> --- a/xen/common/compat/memory.c
> +++ b/xen/common/compat/memory.c
> @@ -26,11 +26,13 @@ int compat_memory_op(unsigned int cmd, X
>              XEN_GUEST_HANDLE_PARAM(void) hnd;
>              struct xen_memory_reservation *rsrv;
>              struct xen_memory_exchange *xchg;
> +            struct xen_add_to_physmap *atp;
>              struct xen_remove_from_physmap *xrfp;
>          } nat;
>          union {
>              struct compat_memory_reservation rsrv;
>              struct compat_memory_exchange xchg;
> +            struct compat_add_to_physmap atp;
>          } cmp;
>  
>          set_xen_guest_handle(nat.hnd, COMPAT_ARG_XLAT_VIRT_BASE);
> @@ -187,6 +189,14 @@ int compat_memory_op(unsigned int cmd, X
>              nat.hnd = compat;
>              break;
>  
> +        case XENMEM_add_to_physmap:
> +            if ( copy_from_guest(&cmp.atp, compat, 1) )
> +                return -EFAULT;
> +
> +            XLAT_add_to_physmap(nat.atp, &cmp.atp);
> +
> +            break;
> +
>          case XENMEM_remove_from_physmap:
>          {
>              struct compat_remove_from_physmap cmp;
> @@ -315,6 +325,16 @@ int compat_memory_op(unsigned int cmd, X
>          case XENMEM_remove_from_physmap:
>              break;
>  
> +        case XENMEM_add_to_physmap:
> +            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
> +                break;

Why is this check here in the compat layer?  Surely the -ENOSYS from
do_memory_op is sufficient to be included in the !rc check ?

> +
> +            XLAT_add_to_physmap(&cmp.atp, nat.atp);
> +            if ( __copy_to_guest(compat, &cmp.atp, 1) )
> +                rc = -EFAULT;
> +
> +            break;
> +
>          default:
>              domain_crash(current->domain);
>              split = 0;
> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -542,6 +542,53 @@ static long memory_exchange(XEN_GUEST_HA
>      return rc;
>  }
>  
> +static int xenmem_add_to_physmap(struct domain *d,
> +                                 struct xen_add_to_physmap *xatp)
> +{
> +    struct xen_add_to_physmap start_xatp;
> +    int rc = 0;
> +
> +    if ( xatp->space != XENMAPSPACE_gmfn_range )
> +        return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
> +                                         xatp->idx, xatp->gpfn);
> +
> +#ifdef HAS_PASSTHROUGH
> +    if ( need_iommu(d) )
> +        this_cpu(iommu_dont_flush_iotlb) = 1;
> +#endif
> +
> +    start_xatp = *xatp;
> +    while ( xatp->size > 0 )
> +    {
> +        rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
> +                                       xatp->idx, xatp->gpfn);
> +        if ( rc < 0 )
> +            break;
> +
> +        xatp->idx++;
> +        xatp->gpfn++;
> +        xatp->size--;
> +
> +        /* Check for continuation if it's not the last iteration. */
> +        if ( xatp->size > 0 && hypercall_preempt_check() )
> +        {
> +            rc = -EAGAIN;
> +            break;
> +        }
> +    }
> +
> +#ifdef HAS_PASSTHROUGH
> +    if ( need_iommu(d) )
> +    {
> +        this_cpu(iommu_dont_flush_iotlb) = 0;
> +        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
> +        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
> +    }
> +#endif
> +
> +    return rc;
> +}
> +
>  long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>  {
>      struct domain *d;
> @@ -673,6 +720,44 @@ long do_memory_op(unsigned long cmd, XEN
>  
>          break;
>  
> +    case XENMEM_add_to_physmap:
> +    {
> +        struct xen_add_to_physmap xatp;
> +
> +        if ( copy_from_guest(&xatp, arg, 1) )
> +            return -EFAULT;
> +
> +        /* Foreign mapping is only possible via add_to_physmap_range. */
> +        if ( xatp.space == XENMAPSPACE_gmfn_foreign )
> +            return -ENOSYS;
> +
> +        d = rcu_lock_domain_by_any_id(xatp.domid);
> +        if ( d == NULL )
> +            return -ESRCH;
> +
> +        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
> +        if ( rc )
> +        {
> +            rcu_unlock_domain(d);
> +            return rc;
> +        }
> +
> +        rc = xenmem_add_to_physmap(d, &xatp);
> +
> +        rcu_unlock_domain(d);
> +
> +        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
> +        {
> +            if ( !__copy_to_guest(arg, &xatp, 1) )
> +                rc = hypercall_create_continuation(
> +                        __HYPERVISOR_memory_op, "ih", op, arg);
> +            else
> +                rc = -EFAULT;
> +        }
> +
> +        return rc;
> +    }
> +
>      case XENMEM_remove_from_physmap:
>      {
>          struct xen_remove_from_physmap xrfp;
> --- a/xen/include/xen/mm.h
> +++ b/xen/include/xen/mm.h
> @@ -356,6 +356,10 @@ static inline unsigned int get_order_fro
>  
>  void scrub_one_page(struct page_info *);
>  
> +int xenmem_add_to_physmap_one(struct domain *d, uint16_t space,
> +                              domid_t foreign_domid,
> +                              unsigned long idx, xen_pfn_t gpfn);
> +
>  /* Returns 1 on success, 0 on error, negative if the ring
>   * for event propagation is full in the presence of paging */
>  int guest_remove_page(struct domain *d, unsigned long gmfn);
>
>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel


[-- Attachment #1.2: Type: text/html, Size: 15555 bytes --]

[-- Attachment #2: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

Re: [PATCH v3 1/5] move XENMEM_add_to_physmap handling framework to common code

[Jan Beulich]

>>> On 20.12.13 at 13:26, Andrew Cooper <andrew.cooper3@citrix.com> wrote:
> On 20/12/13 10:41, Jan Beulich wrote:
>> +        case XENMEM_add_to_physmap:
>> +            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
>> +                break;
> 
> Why is this check here in the compat layer?  Surely the -ENOSYS from
> do_memory_op is sufficient to be included in the !rc check ?
> 
>> +
>> +            XLAT_add_to_physmap(&cmp.atp, nat.atp);
>> +            if ( __copy_to_guest(compat, &cmp.atp, 1) )
>> +                rc = -EFAULT;
>> +
>> +            break;

You mis-read the meaning of the check: The reverse translation
was necessary (it's gone with patch 2 anyway) only when
wanting to copy back into the interface structure. Since that
code is gone with us no longer doing these invalid modifications,
any possible incorrectness here is moot now anyway.

Jan

[PATCH v3 2/5] fix XENMEM_add_to_physmap preemption handling

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 5386 bytes --]

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: drop bogus ASSERT()

--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -190,6 +190,9 @@ int compat_memory_op(unsigned int cmd, X
             break;
 
         case XENMEM_add_to_physmap:
+            BUILD_BUG_ON((typeof(cmp.atp.size))-1 >
+                         (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
             if ( copy_from_guest(&cmp.atp, compat, 1) )
                 return -EFAULT;
 
@@ -322,17 +325,8 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_current_reservation:
         case XENMEM_maximum_reservation:
         case XENMEM_maximum_gpfn:
-        case XENMEM_remove_from_physmap:
-            break;
-
         case XENMEM_add_to_physmap:
-            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
-                break;
-
-            XLAT_add_to_physmap(&cmp.atp, nat.atp);
-            if ( __copy_to_guest(compat, &cmp.atp, 1) )
-                rc = -EFAULT;
-
+        case XENMEM_remove_from_physmap:
             break;
 
         default:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -543,22 +543,29 @@ static long memory_exchange(XEN_GUEST_HA
 }
 
 static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
+                                 struct xen_add_to_physmap *xatp,
+                                 unsigned int start)
 {
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
+    unsigned int done = 0;
+    long rc = 0;
 
     if ( xatp->space != XENMAPSPACE_gmfn_range )
         return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                          xatp->idx, xatp->gpfn);
 
+    if ( xatp->size < start )
+        return -EILSEQ;
+
+    xatp->idx += start;
+    xatp->gpfn += start;
+    xatp->size -= start;
+
 #ifdef HAS_PASSTHROUGH
     if ( need_iommu(d) )
         this_cpu(iommu_dont_flush_iotlb) = 1;
 #endif
 
-    start_xatp = *xatp;
-    while ( xatp->size > 0 )
+    while ( xatp->size > done )
     {
         rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                        xatp->idx, xatp->gpfn);
@@ -567,12 +574,11 @@ static int xenmem_add_to_physmap(struct 
 
         xatp->idx++;
         xatp->gpfn++;
-        xatp->size--;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatp->size > 0 && hypercall_preempt_check() )
+        if ( xatp->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             break;
         }
     }
@@ -581,8 +587,8 @@ static int xenmem_add_to_physmap(struct 
     if ( need_iommu(d) )
     {
         this_cpu(iommu_dont_flush_iotlb) = 0;
-        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, xatp->idx - done, done);
+        iommu_iotlb_flush(d, xatp->gpfn - done, done);
     }
 #endif
 
@@ -594,10 +600,10 @@ long do_memory_op(unsigned long cmd, XEN
     struct domain *d;
     long rc;
     unsigned int address_bits;
-    unsigned long start_extent;
     struct xen_memory_reservation reservation;
     struct memop_args args;
     domid_t domid;
+    unsigned long start_extent = cmd >> MEMOP_EXTENT_SHIFT;
     int op = cmd & MEMOP_CMD_MASK;
 
     switch ( op )
@@ -605,8 +611,6 @@ long do_memory_op(unsigned long cmd, XEN
     case XENMEM_increase_reservation:
     case XENMEM_decrease_reservation:
     case XENMEM_populate_physmap:
-        start_extent = cmd >> MEMOP_EXTENT_SHIFT;
-
         if ( copy_from_guest(&reservation, arg, 1) )
             return start_extent;
 
@@ -724,6 +728,12 @@ long do_memory_op(unsigned long cmd, XEN
     {
         struct xen_add_to_physmap xatp;
 
+        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for malicious or buggy input. */
+        if ( start_extent != (typeof(xatp.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
@@ -742,18 +752,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap(d, &xatp);
+        rc = xenmem_add_to_physmap(d, &xatp, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatp, 1) )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc > 0 )
+            rc = hypercall_create_continuation(
+                     __HYPERVISOR_memory_op, "lh",
+                     op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }



[-- Attachment #2: xatp-preemption.patch --]
[-- Type: text/plain, Size: 5431 bytes --]

fix XENMEM_add_to_physmap preemption handling

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: drop bogus ASSERT()

--- a/xen/common/compat/memory.c
+++ b/xen/common/compat/memory.c
@@ -190,6 +190,9 @@ int compat_memory_op(unsigned int cmd, X
             break;
 
         case XENMEM_add_to_physmap:
+            BUILD_BUG_ON((typeof(cmp.atp.size))-1 >
+                         (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
             if ( copy_from_guest(&cmp.atp, compat, 1) )
                 return -EFAULT;
 
@@ -322,17 +325,8 @@ int compat_memory_op(unsigned int cmd, X
         case XENMEM_current_reservation:
         case XENMEM_maximum_reservation:
         case XENMEM_maximum_gpfn:
-        case XENMEM_remove_from_physmap:
-            break;
-
         case XENMEM_add_to_physmap:
-            if ( !rc || cmp.atp.space != XENMAPSPACE_gmfn_range )
-                break;
-
-            XLAT_add_to_physmap(&cmp.atp, nat.atp);
-            if ( __copy_to_guest(compat, &cmp.atp, 1) )
-                rc = -EFAULT;
-
+        case XENMEM_remove_from_physmap:
             break;
 
         default:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -543,22 +543,29 @@ static long memory_exchange(XEN_GUEST_HA
 }
 
 static int xenmem_add_to_physmap(struct domain *d,
-                                 struct xen_add_to_physmap *xatp)
+                                 struct xen_add_to_physmap *xatp,
+                                 unsigned int start)
 {
-    struct xen_add_to_physmap start_xatp;
-    int rc = 0;
+    unsigned int done = 0;
+    long rc = 0;
 
     if ( xatp->space != XENMAPSPACE_gmfn_range )
         return xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                          xatp->idx, xatp->gpfn);
 
+    if ( xatp->size < start )
+        return -EILSEQ;
+
+    xatp->idx += start;
+    xatp->gpfn += start;
+    xatp->size -= start;
+
 #ifdef HAS_PASSTHROUGH
     if ( need_iommu(d) )
         this_cpu(iommu_dont_flush_iotlb) = 1;
 #endif
 
-    start_xatp = *xatp;
-    while ( xatp->size > 0 )
+    while ( xatp->size > done )
     {
         rc = xenmem_add_to_physmap_one(d, xatp->space, DOMID_INVALID,
                                        xatp->idx, xatp->gpfn);
@@ -567,12 +574,11 @@ static int xenmem_add_to_physmap(struct 
 
         xatp->idx++;
         xatp->gpfn++;
-        xatp->size--;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatp->size > 0 && hypercall_preempt_check() )
+        if ( xatp->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             break;
         }
     }
@@ -581,8 +587,8 @@ static int xenmem_add_to_physmap(struct 
     if ( need_iommu(d) )
     {
         this_cpu(iommu_dont_flush_iotlb) = 0;
-        iommu_iotlb_flush(d, start_xatp.idx, start_xatp.size - xatp->size);
-        iommu_iotlb_flush(d, start_xatp.gpfn, start_xatp.size - xatp->size);
+        iommu_iotlb_flush(d, xatp->idx - done, done);
+        iommu_iotlb_flush(d, xatp->gpfn - done, done);
     }
 #endif
 
@@ -594,10 +600,10 @@ long do_memory_op(unsigned long cmd, XEN
     struct domain *d;
     long rc;
     unsigned int address_bits;
-    unsigned long start_extent;
     struct xen_memory_reservation reservation;
     struct memop_args args;
     domid_t domid;
+    unsigned long start_extent = cmd >> MEMOP_EXTENT_SHIFT;
     int op = cmd & MEMOP_CMD_MASK;
 
     switch ( op )
@@ -605,8 +611,6 @@ long do_memory_op(unsigned long cmd, XEN
     case XENMEM_increase_reservation:
     case XENMEM_decrease_reservation:
     case XENMEM_populate_physmap:
-        start_extent = cmd >> MEMOP_EXTENT_SHIFT;
-
         if ( copy_from_guest(&reservation, arg, 1) )
             return start_extent;
 
@@ -724,6 +728,12 @@ long do_memory_op(unsigned long cmd, XEN
     {
         struct xen_add_to_physmap xatp;
 
+        BUILD_BUG_ON((typeof(xatp.size))-1 > (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for malicious or buggy input. */
+        if ( start_extent != (typeof(xatp.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
@@ -742,18 +752,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap(d, &xatp);
+        rc = xenmem_add_to_physmap(d, &xatp, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( xatp.space == XENMAPSPACE_gmfn_range && rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatp, 1) )
-                rc = hypercall_create_continuation(
-                        __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( xatp.space == XENMAPSPACE_gmfn_range && rc > 0 )
+            rc = hypercall_create_continuation(
+                     __HYPERVISOR_memory_op, "lh",
+                     op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

Re: [PATCH v3 2/5] fix XENMEM_add_to_physmap preemption handling

[Ian Campbell]

On Fri, 2013-12-20 at 10:42 +0000, Jan Beulich wrote:
> Just like for all other hypercalls we shouldn't be modifying the input
> structure - all of the fields are, even if not explicitly documented,
> just inputs.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Tim Deegan <tim@xen.org>
> Acked-by: Keir Fraser <keir@xen.org>

Acked-by: Ian Campbell <ian.campbell@citrix.com>

[PATCH v3 3/5] move XENMEM_add_to_physmap_range handling framework to common code

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 6303 bytes --]

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

This further eliminates the erroneous bailing from
xenmem_add_to_physmap_range() if xenmem_add_to_physmap_one() fails.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: Restore restriction of XENMAPSPACE_gmfn_range only being supported
    through XENMEM_add_to_physmap.

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1057,103 +1057,10 @@ int xenmem_add_to_physmap_one(
     return rc;
 }
 
-static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
-{
-    int rc;
-
-    while ( xatpr->size > 0 )
-    {
-        xen_ulong_t idx;
-        xen_pfn_t gpfn;
-
-        if ( unlikely(copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( unlikely(copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatpr->space,
-                                       xatpr->foreign_domid,
-                                       idx, gpfn);
-
-        if ( unlikely(copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( rc < 0 )
-            goto out;
-
-        guest_handle_add_offset(xatpr->idxs, 1);
-        guest_handle_add_offset(xatpr->gpfns, 1);
-        guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
-
-        /* Check for continuation if it's not the last interation */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
-        {
-            rc = -EAGAIN;
-            goto out;
-        }
-    }
-
-    rc = 0;
-
-out:
-    return rc;
-
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    int rc;
-
     switch ( op )
     {
-    case XENMEM_add_to_physmap_range:
-    {
-        struct xen_add_to_physmap_range xatpr;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatpr, arg, 1) )
-            return -EFAULT;
-
-        /* This mapspace is redundant for this hypercall */
-        if ( xatpr.space == XENMAPSPACE_gmfn_range )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatpr.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
-
-        rcu_unlock_domain(d);
-
-        if ( rc && copy_to_guest(arg, &xatpr, 1) )
-            rc = -EFAULT;
-
-        if ( rc == -EAGAIN )
-            rc = hypercall_create_continuation(
-                __HYPERVISOR_memory_op, "ih", op, arg);
-
-        return rc;
-    }
     /* XXX: memsharing not working yet */
     case XENMEM_get_sharing_shared_pages:
     case XENMEM_get_sharing_freed_pages:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -595,6 +595,57 @@ static int xenmem_add_to_physmap(struct 
     return rc;
 }
 
+static int xenmem_add_to_physmap_range(struct domain *d,
+                                       struct xen_add_to_physmap_range *xatpr)
+{
+    int rc;
+
+    while ( xatpr->size > 0 )
+    {
+        xen_ulong_t idx;
+        xen_pfn_t gpfn;
+
+        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        rc = xenmem_add_to_physmap_one(d, xatpr->space,
+                                       xatpr->foreign_domid,
+                                       idx, gpfn);
+
+        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        guest_handle_add_offset(xatpr->idxs, 1);
+        guest_handle_add_offset(xatpr->gpfns, 1);
+        guest_handle_add_offset(xatpr->errs, 1);
+        xatpr->size--;
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            goto out;
+        }
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -764,6 +815,48 @@ long do_memory_op(unsigned long cmd, XEN
         return rc;
     }
 
+    case XENMEM_add_to_physmap_range:
+    {
+        struct xen_add_to_physmap_range xatpr;
+        struct domain *d;
+
+        if ( copy_from_guest(&xatpr, arg, 1) ||
+             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
+             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
+             !guest_handle_okay(xatpr.errs, xatpr.size) )
+            return -EFAULT;
+
+        /* This mapspace is unsupported for this hypercall. */
+        if ( xatpr.space == XENMAPSPACE_gmfn_range )
+            return -EOPNOTSUPP;
+
+        d = rcu_lock_domain_by_any_id(xatpr.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap_range(d, &xatpr);
+
+        rcu_unlock_domain(d);
+
+        if ( rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatpr, 1) )
+                rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;



[-- Attachment #2: xatpr-common.patch --]
[-- Type: text/plain, Size: 6369 bytes --]

move XENMEM_add_to_physmap_range handling framework to common code

There's really nothing really architecture specific here; the
architecture specific handling is limited to
xenmem_add_to_physmap_one().

This further eliminates the erroneous bailing from
xenmem_add_to_physmap_range() if xenmem_add_to_physmap_one() fails.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>
---
v2: Restore restriction of XENMAPSPACE_gmfn_range only being supported
    through XENMEM_add_to_physmap.

--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -1057,103 +1057,10 @@ int xenmem_add_to_physmap_one(
     return rc;
 }
 
-static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
-{
-    int rc;
-
-    while ( xatpr->size > 0 )
-    {
-        xen_ulong_t idx;
-        xen_pfn_t gpfn;
-
-        if ( unlikely(copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( unlikely(copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        rc = xenmem_add_to_physmap_one(d, xatpr->space,
-                                       xatpr->foreign_domid,
-                                       idx, gpfn);
-
-        if ( unlikely(copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
-        {
-            rc = -EFAULT;
-            goto out;
-        }
-
-        if ( rc < 0 )
-            goto out;
-
-        guest_handle_add_offset(xatpr->idxs, 1);
-        guest_handle_add_offset(xatpr->gpfns, 1);
-        guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
-
-        /* Check for continuation if it's not the last interation */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
-        {
-            rc = -EAGAIN;
-            goto out;
-        }
-    }
-
-    rc = 0;
-
-out:
-    return rc;
-
-}
-
 long arch_memory_op(int op, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
-    int rc;
-
     switch ( op )
     {
-    case XENMEM_add_to_physmap_range:
-    {
-        struct xen_add_to_physmap_range xatpr;
-        struct domain *d;
-
-        if ( copy_from_guest(&xatpr, arg, 1) )
-            return -EFAULT;
-
-        /* This mapspace is redundant for this hypercall */
-        if ( xatpr.space == XENMAPSPACE_gmfn_range )
-            return -EINVAL;
-
-        d = rcu_lock_domain_by_any_id(xatpr.domid);
-        if ( d == NULL )
-            return -ESRCH;
-
-        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
-        if ( rc )
-        {
-            rcu_unlock_domain(d);
-            return rc;
-        }
-
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
-
-        rcu_unlock_domain(d);
-
-        if ( rc && copy_to_guest(arg, &xatpr, 1) )
-            rc = -EFAULT;
-
-        if ( rc == -EAGAIN )
-            rc = hypercall_create_continuation(
-                __HYPERVISOR_memory_op, "ih", op, arg);
-
-        return rc;
-    }
     /* XXX: memsharing not working yet */
     case XENMEM_get_sharing_shared_pages:
     case XENMEM_get_sharing_freed_pages:
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -595,6 +595,57 @@ static int xenmem_add_to_physmap(struct 
     return rc;
 }
 
+static int xenmem_add_to_physmap_range(struct domain *d,
+                                       struct xen_add_to_physmap_range *xatpr)
+{
+    int rc;
+
+    while ( xatpr->size > 0 )
+    {
+        xen_ulong_t idx;
+        xen_pfn_t gpfn;
+
+        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        rc = xenmem_add_to_physmap_one(d, xatpr->space,
+                                       xatpr->foreign_domid,
+                                       idx, gpfn);
+
+        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
+        {
+            rc = -EFAULT;
+            goto out;
+        }
+
+        guest_handle_add_offset(xatpr->idxs, 1);
+        guest_handle_add_offset(xatpr->gpfns, 1);
+        guest_handle_add_offset(xatpr->errs, 1);
+        xatpr->size--;
+
+        /* Check for continuation if it's not the last iteration. */
+        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        {
+            rc = -EAGAIN;
+            goto out;
+        }
+    }
+
+    rc = 0;
+
+out:
+    return rc;
+}
+
 long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
     struct domain *d;
@@ -764,6 +815,48 @@ long do_memory_op(unsigned long cmd, XEN
         return rc;
     }
 
+    case XENMEM_add_to_physmap_range:
+    {
+        struct xen_add_to_physmap_range xatpr;
+        struct domain *d;
+
+        if ( copy_from_guest(&xatpr, arg, 1) ||
+             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
+             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
+             !guest_handle_okay(xatpr.errs, xatpr.size) )
+            return -EFAULT;
+
+        /* This mapspace is unsupported for this hypercall. */
+        if ( xatpr.space == XENMAPSPACE_gmfn_range )
+            return -EOPNOTSUPP;
+
+        d = rcu_lock_domain_by_any_id(xatpr.domid);
+        if ( d == NULL )
+            return -ESRCH;
+
+        rc = xsm_add_to_physmap(XSM_TARGET, current->domain, d);
+        if ( rc )
+        {
+            rcu_unlock_domain(d);
+            return rc;
+        }
+
+        rc = xenmem_add_to_physmap_range(d, &xatpr);
+
+        rcu_unlock_domain(d);
+
+        if ( rc == -EAGAIN )
+        {
+            if ( !__copy_to_guest(arg, &xatpr, 1) )
+                rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "ih", op, arg);
+            else
+                rc = -EFAULT;
+        }
+
+        return rc;
+    }
+
     case XENMEM_remove_from_physmap:
     {
         struct xen_remove_from_physmap xrfp;

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
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Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel

Re: [PATCH v3 3/5] move XENMEM_add_to_physmap_range handling framework to common code

[Ian Campbell]

On Fri, 2013-12-20 at 10:42 +0000, Jan Beulich wrote:
> There's really nothing really architecture specific here; the
> architecture specific handling is limited to
> xenmem_add_to_physmap_one().
> 
> This further eliminates the erroneous bailing from
> xenmem_add_to_physmap_range() if xenmem_add_to_physmap_one() fails.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Tim Deegan <tim@xen.org>
> Acked-by: Keir Fraser <keir@xen.org>

Acked-by: Ian Campbell <ian.campbell@citrix.com>

[PATCH v3 4/5] fix XENMEM_add_to_physmap_range preemption handling

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 3125 bytes --]

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs (the one OUT one really refers to the memory pointed to by
that handle rather than the handle itself).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -596,11 +596,21 @@ static int xenmem_add_to_physmap(struct 
 }
 
 static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
+                                       struct xen_add_to_physmap_range *xatpr,
+                                       unsigned int start)
 {
+    unsigned int done = 0;
     int rc;
 
-    while ( xatpr->size > 0 )
+    if ( xatpr->size < start )
+        return -EILSEQ;
+
+    guest_handle_add_offset(xatpr->idxs, start);
+    guest_handle_add_offset(xatpr->gpfns, start);
+    guest_handle_add_offset(xatpr->errs, start);
+    xatpr->size -= start;
+
+    while ( xatpr->size > done )
     {
         xen_ulong_t idx;
         xen_pfn_t gpfn;
@@ -630,12 +640,11 @@ static int xenmem_add_to_physmap_range(s
         guest_handle_add_offset(xatpr->idxs, 1);
         guest_handle_add_offset(xatpr->gpfns, 1);
         guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        if ( xatpr->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             goto out;
         }
     }
@@ -820,6 +829,13 @@ long do_memory_op(unsigned long cmd, XEN
         struct xen_add_to_physmap_range xatpr;
         struct domain *d;
 
+        BUILD_BUG_ON((typeof(xatpr.size))-1 >
+                     (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for malicious or buggy input. */
+        if ( start_extent != (typeof(xatpr.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatpr, arg, 1) ||
              !guest_handle_okay(xatpr.idxs, xatpr.size) ||
              !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
@@ -841,18 +857,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
+        rc = xenmem_add_to_physmap_range(d, &xatpr, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatpr, 1) )
-                rc = hypercall_create_continuation(
-                    __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( rc > 0 )
+            rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "lh",
+                    op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }




[-- Attachment #2: xatpr-preemption.patch --]
[-- Type: text/plain, Size: 3174 bytes --]

fix XENMEM_add_to_physmap_range preemption handling

Just like for all other hypercalls we shouldn't be modifying the input
structure - all of the fields are, even if not explicitly documented,
just inputs (the one OUT one really refers to the memory pointed to by
that handle rather than the handle itself).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Tim Deegan <tim@xen.org>
Acked-by: Keir Fraser <keir@xen.org>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -596,11 +596,21 @@ static int xenmem_add_to_physmap(struct 
 }
 
 static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr)
+                                       struct xen_add_to_physmap_range *xatpr,
+                                       unsigned int start)
 {
+    unsigned int done = 0;
     int rc;
 
-    while ( xatpr->size > 0 )
+    if ( xatpr->size < start )
+        return -EILSEQ;
+
+    guest_handle_add_offset(xatpr->idxs, start);
+    guest_handle_add_offset(xatpr->gpfns, start);
+    guest_handle_add_offset(xatpr->errs, start);
+    xatpr->size -= start;
+
+    while ( xatpr->size > done )
     {
         xen_ulong_t idx;
         xen_pfn_t gpfn;
@@ -630,12 +640,11 @@ static int xenmem_add_to_physmap_range(s
         guest_handle_add_offset(xatpr->idxs, 1);
         guest_handle_add_offset(xatpr->gpfns, 1);
         guest_handle_add_offset(xatpr->errs, 1);
-        xatpr->size--;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatpr->size > 0 && hypercall_preempt_check() )
+        if ( xatpr->size > ++done && hypercall_preempt_check() )
         {
-            rc = -EAGAIN;
+            rc = start + done;
             goto out;
         }
     }
@@ -820,6 +829,13 @@ long do_memory_op(unsigned long cmd, XEN
         struct xen_add_to_physmap_range xatpr;
         struct domain *d;
 
+        BUILD_BUG_ON((typeof(xatpr.size))-1 >
+                     (UINT_MAX >> MEMOP_EXTENT_SHIFT));
+
+        /* Check for malicious or buggy input. */
+        if ( start_extent != (typeof(xatpr.size))start_extent )
+            return -EDOM;
+
         if ( copy_from_guest(&xatpr, arg, 1) ||
              !guest_handle_okay(xatpr.idxs, xatpr.size) ||
              !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
@@ -841,18 +857,14 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap_range(d, &xatpr);
+        rc = xenmem_add_to_physmap_range(d, &xatpr, start_extent);
 
         rcu_unlock_domain(d);
 
-        if ( rc == -EAGAIN )
-        {
-            if ( !__copy_to_guest(arg, &xatpr, 1) )
-                rc = hypercall_create_continuation(
-                    __HYPERVISOR_memory_op, "ih", op, arg);
-            else
-                rc = -EFAULT;
-        }
+        if ( rc > 0 )
+            rc = hypercall_create_continuation(
+                    __HYPERVISOR_memory_op, "lh",
+                    op | (rc << MEMOP_EXTENT_SHIFT), arg);
 
         return rc;
     }

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

_______________________________________________
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http://lists.xen.org/xen-devel

Re: [PATCH v3 4/5] fix XENMEM_add_to_physmap_range preemption handling

[Ian Campbell]

On Fri, 2013-12-20 at 10:43 +0000, Jan Beulich wrote:
> Just like for all other hypercalls we shouldn't be modifying the input
> structure - all of the fields are, even if not explicitly documented,
> just inputs (the one OUT one really refers to the memory pointed to by
> that handle rather than the handle itself).
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Tim Deegan <tim@xen.org>
> Acked-by: Keir Fraser <keir@xen.org>

Acked-by: Ian Campbell <ian.campbell@citrix.com>

[PATCH v3 5/5] rename XENMEM_add_to_physmap_{range => batch}

[Jan Beulich]

[-- Attachment #1: Type: text/plain, Size: 7402 bytes --]

The use of "range" here wasn't really correct - there are no ranges
involved. As the comment in the public header already correctly said,
all this is about is batching of XENMEM_add_to_physmap calls (with
the addition of having a way to specify a foreign domain for
XENMAPSPACE_gmfn_foreign).

Suggested-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -595,54 +595,54 @@ static int xenmem_add_to_physmap(struct 
     return rc;
 }
 
-static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr,
+static int xenmem_add_to_physmap_batch(struct domain *d,
+                                       struct xen_add_to_physmap_batch *xatpb,
                                        unsigned int start)
 {
     unsigned int done = 0;
     int rc;
 
-    if ( xatpr->size < start )
+    if ( xatpb->size < start )
         return -EILSEQ;
 
-    guest_handle_add_offset(xatpr->idxs, start);
-    guest_handle_add_offset(xatpr->gpfns, start);
-    guest_handle_add_offset(xatpr->errs, start);
-    xatpr->size -= start;
+    guest_handle_add_offset(xatpb->idxs, start);
+    guest_handle_add_offset(xatpb->gpfns, start);
+    guest_handle_add_offset(xatpb->errs, start);
+    xatpb->size -= start;
 
-    while ( xatpr->size > done )
+    while ( xatpb->size > done )
     {
         xen_ulong_t idx;
         xen_pfn_t gpfn;
 
-        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
+        if ( unlikely(__copy_from_guest_offset(&idx, xatpb->idxs, 0, 1)) )
         {
             rc = -EFAULT;
             goto out;
         }
 
-        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
+        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpb->gpfns, 0, 1)) )
         {
             rc = -EFAULT;
             goto out;
         }
 
-        rc = xenmem_add_to_physmap_one(d, xatpr->space,
-                                       xatpr->foreign_domid,
+        rc = xenmem_add_to_physmap_one(d, xatpb->space,
+                                       xatpb->foreign_domid,
                                        idx, gpfn);
 
-        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
+        if ( unlikely(__copy_to_guest_offset(xatpb->errs, 0, &rc, 1)) )
         {
             rc = -EFAULT;
             goto out;
         }
 
-        guest_handle_add_offset(xatpr->idxs, 1);
-        guest_handle_add_offset(xatpr->gpfns, 1);
-        guest_handle_add_offset(xatpr->errs, 1);
+        guest_handle_add_offset(xatpb->idxs, 1);
+        guest_handle_add_offset(xatpb->gpfns, 1);
+        guest_handle_add_offset(xatpb->errs, 1);
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatpr->size > ++done && hypercall_preempt_check() )
+        if ( xatpb->size > ++done && hypercall_preempt_check() )
         {
             rc = start + done;
             goto out;
@@ -797,7 +797,7 @@ long do_memory_op(unsigned long cmd, XEN
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
-        /* Foreign mapping is only possible via add_to_physmap_range. */
+        /* Foreign mapping is only possible via add_to_physmap_batch. */
         if ( xatp.space == XENMAPSPACE_gmfn_foreign )
             return -ENOSYS;
 
@@ -824,29 +824,29 @@ long do_memory_op(unsigned long cmd, XEN
         return rc;
     }
 
-    case XENMEM_add_to_physmap_range:
+    case XENMEM_add_to_physmap_batch:
     {
-        struct xen_add_to_physmap_range xatpr;
+        struct xen_add_to_physmap_batch xatpb;
         struct domain *d;
 
-        BUILD_BUG_ON((typeof(xatpr.size))-1 >
+        BUILD_BUG_ON((typeof(xatpb.size))-1 >
                      (UINT_MAX >> MEMOP_EXTENT_SHIFT));
 
         /* Check for malicious or buggy input. */
-        if ( start_extent != (typeof(xatpr.size))start_extent )
+        if ( start_extent != (typeof(xatpb.size))start_extent )
             return -EDOM;
 
-        if ( copy_from_guest(&xatpr, arg, 1) ||
-             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
-             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
-             !guest_handle_okay(xatpr.errs, xatpr.size) )
+        if ( copy_from_guest(&xatpb, arg, 1) ||
+             !guest_handle_okay(xatpb.idxs, xatpb.size) ||
+             !guest_handle_okay(xatpb.gpfns, xatpb.size) ||
+             !guest_handle_okay(xatpb.errs, xatpb.size) )
             return -EFAULT;
 
         /* This mapspace is unsupported for this hypercall. */
-        if ( xatpr.space == XENMAPSPACE_gmfn_range )
+        if ( xatpb.space == XENMAPSPACE_gmfn_range )
             return -EOPNOTSUPP;
 
-        d = rcu_lock_domain_by_any_id(xatpr.domid);
+        d = rcu_lock_domain_by_any_id(xatpb.domid);
         if ( d == NULL )
             return -ESRCH;
 
@@ -857,7 +857,7 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap_range(d, &xatpr, start_extent);
+        rc = xenmem_add_to_physmap_batch(d, &xatpb, start_extent);
 
         rcu_unlock_domain(d);
 
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -79,7 +79,7 @@
  *
  *   In addition the following arch specific sub-ops:
  *    * XENMEM_add_to_physmap
- *    * XENMEM_add_to_physmap_range
+ *    * XENMEM_add_to_physmap_batch
  *
  *  HYPERVISOR_domctl
  *   All generic sub-operations, with the exception of:
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -207,8 +207,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_machphys_map
 #define XENMAPSPACE_gmfn         2 /* GMFN */
 #define XENMAPSPACE_gmfn_range   3 /* GMFN range, XENMEM_add_to_physmap only. */
 #define XENMAPSPACE_gmfn_foreign 4 /* GMFN from another dom,
-                                    * XENMEM_add_to_physmap_range only.
-                                    */
+                                    * XENMEM_add_to_physmap_batch only. */
 /* ` } */
 
 /*
@@ -238,8 +237,8 @@ typedef struct xen_add_to_physmap xen_ad
 DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_t);
 
 /* A batched version of add_to_physmap. */
-#define XENMEM_add_to_physmap_range 23
-struct xen_add_to_physmap_range {
+#define XENMEM_add_to_physmap_batch 23
+struct xen_add_to_physmap_batch {
     /* IN */
     /* Which domain to change the mapping for. */
     domid_t domid;
@@ -260,8 +259,15 @@ struct xen_add_to_physmap_range {
     /* Per index error code. */
     XEN_GUEST_HANDLE(int) errs;
 };
-typedef struct xen_add_to_physmap_range xen_add_to_physmap_range_t;
-DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_range_t);
+typedef struct xen_add_to_physmap_batch xen_add_to_physmap_batch_t;
+DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_batch_t);
+
+#if __XEN_INTERFACE_VERSION__ < 0x00040400
+#define XENMEM_add_to_physmap_range XENMEM_add_to_physmap_batch
+#define xen_add_to_physmap_range xen_add_to_physmap_batch
+typedef struct xen_add_to_physmap_batch xen_add_to_physmap_range_t;
+DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_batch_t);
+#endif
 
 /*
  * Unmaps the page appearing at a particular GPFN from the specified guest's



[-- Attachment #2: xatpr-naming.patch --]
[-- Type: text/plain, Size: 7447 bytes --]

rename XENMEM_add_to_physmap_{range => batch}

The use of "range" here wasn't really correct - there are no ranges
involved. As the comment in the public header already correctly said,
all this is about is batching of XENMEM_add_to_physmap calls (with
the addition of having a way to specify a foreign domain for
XENMAPSPACE_gmfn_foreign).

Suggested-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -595,54 +595,54 @@ static int xenmem_add_to_physmap(struct 
     return rc;
 }
 
-static int xenmem_add_to_physmap_range(struct domain *d,
-                                       struct xen_add_to_physmap_range *xatpr,
+static int xenmem_add_to_physmap_batch(struct domain *d,
+                                       struct xen_add_to_physmap_batch *xatpb,
                                        unsigned int start)
 {
     unsigned int done = 0;
     int rc;
 
-    if ( xatpr->size < start )
+    if ( xatpb->size < start )
         return -EILSEQ;
 
-    guest_handle_add_offset(xatpr->idxs, start);
-    guest_handle_add_offset(xatpr->gpfns, start);
-    guest_handle_add_offset(xatpr->errs, start);
-    xatpr->size -= start;
+    guest_handle_add_offset(xatpb->idxs, start);
+    guest_handle_add_offset(xatpb->gpfns, start);
+    guest_handle_add_offset(xatpb->errs, start);
+    xatpb->size -= start;
 
-    while ( xatpr->size > done )
+    while ( xatpb->size > done )
     {
         xen_ulong_t idx;
         xen_pfn_t gpfn;
 
-        if ( unlikely(__copy_from_guest_offset(&idx, xatpr->idxs, 0, 1)) )
+        if ( unlikely(__copy_from_guest_offset(&idx, xatpb->idxs, 0, 1)) )
         {
             rc = -EFAULT;
             goto out;
         }
 
-        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpr->gpfns, 0, 1)) )
+        if ( unlikely(__copy_from_guest_offset(&gpfn, xatpb->gpfns, 0, 1)) )
         {
             rc = -EFAULT;
             goto out;
         }
 
-        rc = xenmem_add_to_physmap_one(d, xatpr->space,
-                                       xatpr->foreign_domid,
+        rc = xenmem_add_to_physmap_one(d, xatpb->space,
+                                       xatpb->foreign_domid,
                                        idx, gpfn);
 
-        if ( unlikely(__copy_to_guest_offset(xatpr->errs, 0, &rc, 1)) )
+        if ( unlikely(__copy_to_guest_offset(xatpb->errs, 0, &rc, 1)) )
         {
             rc = -EFAULT;
             goto out;
         }
 
-        guest_handle_add_offset(xatpr->idxs, 1);
-        guest_handle_add_offset(xatpr->gpfns, 1);
-        guest_handle_add_offset(xatpr->errs, 1);
+        guest_handle_add_offset(xatpb->idxs, 1);
+        guest_handle_add_offset(xatpb->gpfns, 1);
+        guest_handle_add_offset(xatpb->errs, 1);
 
         /* Check for continuation if it's not the last iteration. */
-        if ( xatpr->size > ++done && hypercall_preempt_check() )
+        if ( xatpb->size > ++done && hypercall_preempt_check() )
         {
             rc = start + done;
             goto out;
@@ -797,7 +797,7 @@ long do_memory_op(unsigned long cmd, XEN
         if ( copy_from_guest(&xatp, arg, 1) )
             return -EFAULT;
 
-        /* Foreign mapping is only possible via add_to_physmap_range. */
+        /* Foreign mapping is only possible via add_to_physmap_batch. */
         if ( xatp.space == XENMAPSPACE_gmfn_foreign )
             return -ENOSYS;
 
@@ -824,29 +824,29 @@ long do_memory_op(unsigned long cmd, XEN
         return rc;
     }
 
-    case XENMEM_add_to_physmap_range:
+    case XENMEM_add_to_physmap_batch:
     {
-        struct xen_add_to_physmap_range xatpr;
+        struct xen_add_to_physmap_batch xatpb;
         struct domain *d;
 
-        BUILD_BUG_ON((typeof(xatpr.size))-1 >
+        BUILD_BUG_ON((typeof(xatpb.size))-1 >
                      (UINT_MAX >> MEMOP_EXTENT_SHIFT));
 
         /* Check for malicious or buggy input. */
-        if ( start_extent != (typeof(xatpr.size))start_extent )
+        if ( start_extent != (typeof(xatpb.size))start_extent )
             return -EDOM;
 
-        if ( copy_from_guest(&xatpr, arg, 1) ||
-             !guest_handle_okay(xatpr.idxs, xatpr.size) ||
-             !guest_handle_okay(xatpr.gpfns, xatpr.size) ||
-             !guest_handle_okay(xatpr.errs, xatpr.size) )
+        if ( copy_from_guest(&xatpb, arg, 1) ||
+             !guest_handle_okay(xatpb.idxs, xatpb.size) ||
+             !guest_handle_okay(xatpb.gpfns, xatpb.size) ||
+             !guest_handle_okay(xatpb.errs, xatpb.size) )
             return -EFAULT;
 
         /* This mapspace is unsupported for this hypercall. */
-        if ( xatpr.space == XENMAPSPACE_gmfn_range )
+        if ( xatpb.space == XENMAPSPACE_gmfn_range )
             return -EOPNOTSUPP;
 
-        d = rcu_lock_domain_by_any_id(xatpr.domid);
+        d = rcu_lock_domain_by_any_id(xatpb.domid);
         if ( d == NULL )
             return -ESRCH;
 
@@ -857,7 +857,7 @@ long do_memory_op(unsigned long cmd, XEN
             return rc;
         }
 
-        rc = xenmem_add_to_physmap_range(d, &xatpr, start_extent);
+        rc = xenmem_add_to_physmap_batch(d, &xatpb, start_extent);
 
         rcu_unlock_domain(d);
 
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -79,7 +79,7 @@
  *
  *   In addition the following arch specific sub-ops:
  *    * XENMEM_add_to_physmap
- *    * XENMEM_add_to_physmap_range
+ *    * XENMEM_add_to_physmap_batch
  *
  *  HYPERVISOR_domctl
  *   All generic sub-operations, with the exception of:
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -207,8 +207,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_machphys_map
 #define XENMAPSPACE_gmfn         2 /* GMFN */
 #define XENMAPSPACE_gmfn_range   3 /* GMFN range, XENMEM_add_to_physmap only. */
 #define XENMAPSPACE_gmfn_foreign 4 /* GMFN from another dom,
-                                    * XENMEM_add_to_physmap_range only.
-                                    */
+                                    * XENMEM_add_to_physmap_batch only. */
 /* ` } */
 
 /*
@@ -238,8 +237,8 @@ typedef struct xen_add_to_physmap xen_ad
 DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_t);
 
 /* A batched version of add_to_physmap. */
-#define XENMEM_add_to_physmap_range 23
-struct xen_add_to_physmap_range {
+#define XENMEM_add_to_physmap_batch 23
+struct xen_add_to_physmap_batch {
     /* IN */
     /* Which domain to change the mapping for. */
     domid_t domid;
@@ -260,8 +259,15 @@ struct xen_add_to_physmap_range {
     /* Per index error code. */
     XEN_GUEST_HANDLE(int) errs;
 };
-typedef struct xen_add_to_physmap_range xen_add_to_physmap_range_t;
-DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_range_t);
+typedef struct xen_add_to_physmap_batch xen_add_to_physmap_batch_t;
+DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_batch_t);
+
+#if __XEN_INTERFACE_VERSION__ < 0x00040400
+#define XENMEM_add_to_physmap_range XENMEM_add_to_physmap_batch
+#define xen_add_to_physmap_range xen_add_to_physmap_batch
+typedef struct xen_add_to_physmap_batch xen_add_to_physmap_range_t;
+DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_batch_t);
+#endif
 
 /*
  * Unmaps the page appearing at a particular GPFN from the specified guest's

[-- Attachment #3: Type: text/plain, Size: 126 bytes --]

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Re: [PATCH v3 5/5] rename XENMEM_add_to_physmap_{range => batch}

[Ian Campbell]

On Fri, 2013-12-20 at 10:44 +0000, Jan Beulich wrote:
> +#if __XEN_INTERFACE_VERSION__ < 0x00040400
> +#define XENMEM_add_to_physmap_range XENMEM_add_to_physmap_batch
> +#define xen_add_to_physmap_range xen_add_to_physmap_batch
> +typedef struct xen_add_to_physmap_batch xen_add_to_physmap_range_t;
> +DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_batch_t);

This last one should be a x_a_t_p_range_t I think?

> +#endif
>  
>  /*
>   * Unmaps the page appearing at a particular GPFN from the specified guest's
> 
> 

Re: [PATCH v3 5/5] rename XENMEM_add_to_physmap_{range => batch}

[Jan Beulich]

>>> On 20.12.13 at 11:55, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> On Fri, 2013-12-20 at 10:44 +0000, Jan Beulich wrote:
>> +#if __XEN_INTERFACE_VERSION__ < 0x00040400
>> +#define XENMEM_add_to_physmap_range XENMEM_add_to_physmap_batch
>> +#define xen_add_to_physmap_range xen_add_to_physmap_batch
>> +typedef struct xen_add_to_physmap_batch xen_add_to_physmap_range_t;
>> +DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_batch_t);
> 
> This last one should be a x_a_t_p_range_t I think?

Oh, yes, of course.

Jan

Re: [PATCH v3 5/5] rename XENMEM_add_to_physmap_{range => batch}

[Ian Campbell]

On Fri, 2013-12-20 at 12:05 +0000, Jan Beulich wrote:
> >>> On 20.12.13 at 11:55, Ian Campbell <Ian.Campbell@citrix.com> wrote:
> > On Fri, 2013-12-20 at 10:44 +0000, Jan Beulich wrote:
> >> +#if __XEN_INTERFACE_VERSION__ < 0x00040400
> >> +#define XENMEM_add_to_physmap_range XENMEM_add_to_physmap_batch
> >> +#define xen_add_to_physmap_range xen_add_to_physmap_batch
> >> +typedef struct xen_add_to_physmap_batch xen_add_to_physmap_range_t;
> >> +DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_batch_t);
> > 
> > This last one should be a x_a_t_p_range_t I think?
> 
> Oh, yes, of course.

I had also meant to say:

With that change:
Acked-by: Ian Campbell <ian.campbell@citrix.com>

Ian.