[PATCH 0 of 2] RFC More get-page-from-gfn

[PATCH 0 of 2] RFC More get-page-from-gfn

[Andres Lagar-Cavilla]

RFC, expanding the monster patch with more call sites and bugfixes.

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavaill.org>

 xen/arch/x86/hvm/svm/svm.c |  20 +++++++-----------
 xen/arch/x86/mm.c          |  48 ++++++++++++++++++---------------------------
 xen/common/memory.c        |   9 +++++++-
 xen/common/tmem_xen.c      |  26 +++++++++---------------
 xen/include/asm-x86/p2m.h  |  11 ----------
 xen/xsm/flask/hooks.c      |  19 ++++++++++++++---
 6 files changed, 60 insertions(+), 73 deletions(-)

[PATCH 1 of 2] Use get page from gfn also in svm code

[Andres Lagar-Cavilla]

 xen/arch/x86/hvm/svm/svm.c |  20 ++++++++------------
 1 files changed, 8 insertions(+), 12 deletions(-)


And clean up some unnecessary uses of get_gfn locked.

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>

diff -r 310e84676db3 -r 42634eca923f xen/arch/x86/hvm/svm/svm.c
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -232,8 +232,7 @@ static int svm_vmcb_save(struct vcpu *v,
 
 static int svm_vmcb_restore(struct vcpu *v, struct hvm_hw_cpu *c)
 {
-    unsigned long mfn = 0;
-    p2m_type_t p2mt;
+    struct page_info *page = NULL;
     struct vmcb_struct *vmcb = v->arch.hvm_svm.vmcb;
     struct p2m_domain *p2m = p2m_get_hostp2m(v->domain);
 
@@ -250,10 +249,10 @@ static int svm_vmcb_restore(struct vcpu 
     {
         if ( c->cr0 & X86_CR0_PG )
         {
-            mfn = mfn_x(get_gfn(v->domain, c->cr3 >> PAGE_SHIFT, &p2mt));
-            if ( !p2m_is_ram(p2mt) || !get_page(mfn_to_page(mfn), v->domain) )
+            page = get_page_from_gfn(v->domain, c->cr3 >> PAGE_SHIFT,
+                                     NULL, P2M_ALLOC);
+            if ( !page )
             {
-                put_gfn(v->domain, c->cr3 >> PAGE_SHIFT);
                 gdprintk(XENLOG_ERR, "Invalid CR3 value=0x%"PRIx64"\n",
                          c->cr3);
                 return -EINVAL;
@@ -263,9 +262,8 @@ static int svm_vmcb_restore(struct vcpu 
         if ( v->arch.hvm_vcpu.guest_cr[0] & X86_CR0_PG )
             put_page(pagetable_get_page(v->arch.guest_table));
 
-        v->arch.guest_table = pagetable_from_pfn(mfn);
-        if ( c->cr0 & X86_CR0_PG )
-            put_gfn(v->domain, c->cr3 >> PAGE_SHIFT);
+        v->arch.guest_table = 
+            page ? pagetable_from_page(page) : pagetable_null();
     }
 
     v->arch.hvm_vcpu.guest_cr[0] = c->cr0 | X86_CR0_ET;
@@ -1321,8 +1319,7 @@ static void svm_do_nested_pgfault(struct
         p2m = p2m_get_p2m(v);
         _d.gpa = gpa;
         _d.qualification = 0;
-        mfn = get_gfn_type_access(p2m, gfn, &_d.p2mt, &p2ma, 0, NULL);
-        __put_gfn(p2m, gfn);
+        mfn = __get_gfn_type_access(p2m, gfn, &_d.p2mt, &p2ma, 0, NULL, 0);
         _d.mfn = mfn_x(mfn);
         
         __trace_var(TRC_HVM_NPF, 0, sizeof(_d), &_d);
@@ -1343,8 +1340,7 @@ static void svm_do_nested_pgfault(struct
     if ( p2m == NULL )
         p2m = p2m_get_p2m(v);
     /* Everything else is an error. */
-    mfn = get_gfn_type_access(p2m, gfn, &p2mt, &p2ma, 0, NULL);
-    __put_gfn(p2m, gfn);
+    mfn = __get_gfn_type_access(p2m, gfn, &p2mt, &p2ma, 0, NULL, 0);
     gdprintk(XENLOG_ERR,
          "SVM violation gpa %#"PRIpaddr", mfn %#lx, type %i\n",
          gpa, mfn_x(mfn), p2mt);

[PATCH 2 of 2] Expand use of get_page_from_gfn

[Andres Lagar-Cavilla]

 xen/arch/x86/mm.c         |  48 ++++++++++++++++++----------------------------
 xen/common/memory.c       |   9 +++++++-
 xen/common/tmem_xen.c     |  26 +++++++++---------------
 xen/include/asm-x86/p2m.h |  11 ----------
 xen/xsm/flask/hooks.c     |  19 ++++++++++++++---
 5 files changed, 52 insertions(+), 61 deletions(-)


Cover more users in common/memory.c, arch/x86/mm.c, xsm and tmem.

Fix bugs on xsm for get_gfn_untyped and get_page_from_gfn.

Eliminate altogether get_gfn_untyped.

Add appropriate ifdefe'ery in common code so that ARM doesn't whine.

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>

diff -r 42634eca923f -r a840e45febc2 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -3731,18 +3731,17 @@ static int create_grant_pte_mapping(
     adjust_guest_l1e(nl1e, d);
 
     gmfn = pte_addr >> PAGE_SHIFT;
-    mfn = get_gfn_untyped(d, gmfn);
-
-    if ( unlikely(!get_page_from_pagenr(mfn, current->domain)) )
+    page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
+
+    if ( unlikely(!page) )
     {
-        put_gfn(d, gmfn);
         MEM_LOG("Could not get page for normal update");
         return GNTST_general_error;
     }
     
+    mfn = page_to_mfn(page);
     va = map_domain_page(mfn);
     va = (void *)((unsigned long)va + ((unsigned long)pte_addr & ~PAGE_MASK));
-    page = mfn_to_page(mfn);
 
     if ( !page_lock(page) )
     {
@@ -3773,7 +3772,6 @@ static int create_grant_pte_mapping(
  failed:
     unmap_domain_page(va);
     put_page(page);
-    put_gfn(d, gmfn);
 
     return rc;
 }
@@ -3788,18 +3786,17 @@ static int destroy_grant_pte_mapping(
     l1_pgentry_t ol1e;
 
     gmfn = addr >> PAGE_SHIFT;
-    mfn = get_gfn_untyped(d, gmfn);
-
-    if ( unlikely(!get_page_from_pagenr(mfn, current->domain)) )
+    page = get_page_from_gfn(d, gmfn, NULL, P2M_ALLOC);
+
+    if ( unlikely(!page) )
     {
-        put_gfn(d, gmfn);
         MEM_LOG("Could not get page for normal update");
         return GNTST_general_error;
     }
     
+    mfn = page_to_mfn(page);
     va = map_domain_page(mfn);
     va = (void *)((unsigned long)va + ((unsigned long)addr & ~PAGE_MASK));
-    page = mfn_to_page(mfn);
 
     if ( !page_lock(page) )
     {
@@ -3844,7 +3841,6 @@ static int destroy_grant_pte_mapping(
  failed:
     unmap_domain_page(va);
     put_page(page);
-    put_gfn(d, gmfn);
     return rc;
 }
 
@@ -4367,11 +4363,12 @@ long set_gdt(struct vcpu *v,
     /* Check the pages in the new GDT. */
     for ( i = 0; i < nr_pages; i++ )
     {
+        struct page_info *page;
         pfns[i] = frames[i];
-        mfn = frames[i] = get_gfn_untyped(d, frames[i]);
-        if ( !mfn_valid(mfn) ||
-             !get_page_and_type(mfn_to_page(mfn), d, PGT_seg_desc_page) )
+        page = get_page_from_gfn(d, frames[i], NULL, P2M_ALLOC);
+        if ( !page || !get_page_type(page, PGT_seg_desc_page) )
             goto fail;
+        mfn = frames[i] = page_to_mfn(page);
     }
 
     /* Tear down the old GDT. */
@@ -4384,7 +4381,6 @@ long set_gdt(struct vcpu *v,
         v->arch.pv_vcpu.gdt_frames[i] = frames[i];
         l1e_write(&v->arch.perdomain_ptes[i],
                   l1e_from_pfn(frames[i], __PAGE_HYPERVISOR));
-        put_gfn(d, pfns[i]);
     }
 
     xfree(pfns);
@@ -4394,7 +4390,6 @@ long set_gdt(struct vcpu *v,
     while ( i-- > 0 )
     {
         put_page_and_type(mfn_to_page(frames[i]));
-        put_gfn(d, pfns[i]);
     }
     xfree(pfns);
     return -EINVAL;
@@ -4440,21 +4435,16 @@ long do_update_descriptor(u64 pa, u64 de
 
     *(u64 *)&d = desc;
 
-    mfn = get_gfn_untyped(dom, gmfn);
+    page = get_page_from_gfn(dom, gmfn, NULL, P2M_ALLOC);
     if ( (((unsigned int)pa % sizeof(struct desc_struct)) != 0) ||
-         !mfn_valid(mfn) ||
+         !page ||
          !check_descriptor(dom, &d) )
     {
-        put_gfn(dom, gmfn);
+        if ( page )
+            put_page(page);
         return -EINVAL;
     }
-
-    page = mfn_to_page(mfn);
-    if ( unlikely(!get_page(page, dom)) )
-    {
-        put_gfn(dom, gmfn);
-        return -EINVAL;
-    }
+    mfn = page_to_mfn(page);
 
     /* Check if the given frame is in use in an unsafe context. */
     switch ( page->u.inuse.type_info & PGT_type_mask )
@@ -4482,7 +4472,6 @@ long do_update_descriptor(u64 pa, u64 de
 
  out:
     put_page(page);
-    put_gfn(dom, gmfn);
 
     return ret;
 }
@@ -4529,6 +4518,7 @@ static int xenmem_add_to_physmap_once(
     unsigned long gfn = 0; /* gcc ... */
     unsigned long prev_mfn, mfn = 0, gpfn, idx;
     int rc;
+    p2m_type_t p2mt;
 
     switch ( xatp->space )
     {
@@ -4617,7 +4607,7 @@ static int xenmem_add_to_physmap_once(
         put_page(page);
 
     /* Remove previously mapped page if it was present. */
-    prev_mfn = get_gfn_untyped(d, xatp->gpfn);
+    prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
     {
         if ( is_xen_heap_mfn(prev_mfn) )
diff -r 42634eca923f -r a840e45febc2 xen/common/memory.c
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -694,7 +694,14 @@ long do_memory_op(unsigned long cmd, XEN
 
         domain_lock(d);
 
-        mfn = get_gfn_untyped(d, xrfp.gpfn);
+#ifdef CONFIG_X86
+        {
+            p2m_type_t p2mt;
+            mfn = mfn_x(get_gfn(d, xrfp.gpfn, &p2mt));
+        }
+#else
+        mfn = gmfn_to_mfn(d, xrfp.gpfn);
+#endif
 
         if ( mfn_valid(mfn) )
             guest_physmap_remove_page(d, xrfp.gpfn, mfn, 0);
diff -r 42634eca923f -r a840e45febc2 xen/common/tmem_xen.c
--- a/xen/common/tmem_xen.c
+++ b/xen/common/tmem_xen.c
@@ -107,30 +107,25 @@ static inline void cli_put_page(tmem_cli
 static inline void *cli_get_page(tmem_cli_mfn_t cmfn, unsigned long *pcli_mfn,
                                  pfp_t **pcli_pfp, bool_t cli_write)
 {
-    unsigned long cli_mfn;
     p2m_type_t t;
     struct page_info *page;
-    int ret;
 
-    cli_mfn = mfn_x(get_gfn(current->domain, cmfn, &t));
-    if ( t != p2m_ram_rw || !mfn_valid(cli_mfn) )
+    page = get_page_from_gfn(current->domain, cmfn, &t, P2M_ALLOC);
+    if ( !page || t != p2m_ram_rw )
     {
-            put_gfn(current->domain, (unsigned long) cmfn);
-            return NULL;
+        if ( page )
+            put_page(page);
     }
-    page = mfn_to_page(cli_mfn);
-    if ( cli_write )
-        ret = get_page_and_type(page, current->domain, PGT_writable_page);
-    else
-        ret = get_page(page, current->domain);
-    if ( !ret )
+
+    if ( cli_write && !get_page_type(page, PGT_writable_page) )
     {
-        put_gfn(current->domain, (unsigned long) cmfn);
+        put_page(page);
         return NULL;
     }
-    *pcli_mfn = cli_mfn;
+
+    *pcli_mfn = page_to_mfn(page);
     *pcli_pfp = (pfp_t *)page;
-    return map_domain_page(cli_mfn);
+    return map_domain_page(*pcli_mfn);
 }
 
 static inline void cli_put_page(tmem_cli_mfn_t cmfn, void *cli_va, pfp_t *cli_pfp,
@@ -144,7 +139,6 @@ static inline void cli_put_page(tmem_cli
     else
         put_page((struct page_info *)cli_pfp);
     unmap_domain_page(cli_va);
-    put_gfn(current->domain, (unsigned long) cmfn);
 }
 #endif
 
diff -r 42634eca923f -r a840e45febc2 xen/include/asm-x86/p2m.h
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -342,17 +342,6 @@ static inline mfn_t get_gfn_type(struct 
 #define get_gfn_unshare(d, g, t) get_gfn_type((d), (g), (t), \
                                               P2M_ALLOC | P2M_UNSHARE)
 
-/* Compatibility function exporting the old untyped interface */
-static inline unsigned long get_gfn_untyped(struct domain *d, unsigned long gpfn)
-{
-    mfn_t mfn;
-    p2m_type_t t;
-    mfn = get_gfn(d, gpfn, &t);
-    if ( p2m_is_valid(t) )
-        return mfn_x(mfn);
-    return INVALID_MFN;
-}
-
 /* Will release the p2m_lock for this gfn entry. */
 void __put_gfn(struct p2m_domain *p2m, unsigned long gfn);
 
diff -r 42634eca923f -r a840e45febc2 xen/xsm/flask/hooks.c
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -1318,7 +1318,7 @@ static int flask_mmu_normal_update(struc
     struct domain_security_struct *dsec;
     u32 fsid;
     struct avc_audit_data ad;
-    struct page_info *page;
+    struct page_info *page = NULL;
 
     if (d != t)
         rc = domain_has_perm(d, t, SECCLASS_MMU, MMU__REMOTE_REMAP);
@@ -1334,9 +1334,12 @@ static int flask_mmu_normal_update(struc
         map_perms |= MMU__MAP_WRITE;
 
     AVC_AUDIT_DATA_INIT(&ad, MEMORY);
-    page = get_page_from_gfn(f, l1e_get_pfn(l1e_from_intpte(fpte)), P2M_ALLOC);
+#if CONFIG_X86
+    page = get_page_from_gfn(f, l1e_get_pfn(l1e_from_intpte(fpte)), NULL, P2M_ALLOC);
     mfn = page ? page_to_mfn(page) : INVALID_MFN;
-
+#else
+    mfn = gmfn_to_mfn(f, l1e_get_pfn(l1e_from_intpte(fpte)));
+#endif
     ad.sdom = d;
     ad.tdom = f;
     ad.memory.pte = fpte;
@@ -1373,6 +1376,7 @@ static int flask_update_va_mapping(struc
     int rc = 0;
     u32 psid;
     u32 map_perms = MMU__MAP_READ;
+    struct page_info *page = NULL;
     unsigned long mfn;
     struct domain_security_struct *dsec;
 
@@ -1384,8 +1388,15 @@ static int flask_update_va_mapping(struc
 
     dsec = d->ssid;
 
-    mfn = get_gfn_untyped(f, l1e_get_pfn(pte));
+#if CONFIG_X86
+    page = get_page_from_gfn(f, l1e_get_pfn(pte), NULL, P2M_ALLOC);
+    mfn = (page) ? page_to_mfn(page) : INVALID_MFN;
+#else
+    mfn = gmfn_to_mfn(f, l1e_get_pfn(pte));
+#endif
     rc = get_mfn_sid(mfn, &psid);
+    if ( page )
+        put_page(page);
     if ( rc )
         return rc;