[PATCH-for-4.9 v1 5/8] dm_op: convert HVMOP_modified_memory

[Paul Durrant <paul.durrant@citrix.com>]

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Daniel De Graaf <dgdegra@tycho.nsa.gov>
---
 tools/libxc/xc_misc.c               | 26 +++++-----------
 xen/arch/x86/hvm/dm.c               | 54 +++++++++++++++++++++++++++++++++
 xen/arch/x86/hvm/hvm.c              | 60 -------------------------------------
 xen/include/public/hvm/dm_op.h      | 14 +++++++++
 xen/include/public/hvm/hvm_op.h     |  4 +--
 xen/xsm/flask/policy/access_vectors |  2 +-
 6 files changed, 79 insertions(+), 81 deletions(-)

diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
index 842b699..a97864e 100644
--- a/tools/libxc/xc_misc.c
+++ b/tools/libxc/xc_misc.c
@@ -568,27 +568,17 @@ int xc_hvm_track_dirty_vram(
 int xc_hvm_modified_memory(
     xc_interface *xch, domid_t dom, uint64_t first_pfn, uint64_t nr)
 {
-    DECLARE_HYPERCALL_BUFFER(struct xen_hvm_modified_memory, arg);
-    int rc;
-
-    arg = xc_hypercall_buffer_alloc(xch, arg, sizeof(*arg));
-    if ( arg == NULL )
-    {
-        PERROR("Could not allocate memory for xc_hvm_modified_memory hypercall");
-        return -1;
-    }
+    struct xen_dm_op op;
+    struct xen_dm_op_modified_memory *data;
 
-    arg->domid     = dom;
-    arg->first_pfn = first_pfn;
-    arg->nr        = nr;
+    op.op = DMOP_modified_memory;
+    data = &op.u.modified_memory;
 
-    rc = xencall2(xch->xcall, __HYPERVISOR_hvm_op,
-                  HVMOP_modified_memory,
-                  HYPERCALL_BUFFER_AS_ARG(arg));
-
-    xc_hypercall_buffer_free(xch, arg);
+    data->first_pfn = first_pfn;
+    /* NOTE: The following assignment truncates nr to 32-bits */
+    data->nr = nr;
 
-    return rc;
+    return do_dm_op(xch, dom, 1, &op, sizeof(op));
 }
 
 int xc_hvm_set_mem_type(
diff --git a/xen/arch/x86/hvm/dm.c b/xen/arch/x86/hvm/dm.c
index b8edf2c..0dcd454 100644
--- a/xen/arch/x86/hvm/dm.c
+++ b/xen/arch/x86/hvm/dm.c
@@ -17,6 +17,7 @@
 #include <xen/hypercall.h>
 #include <xen/guest_access.h>
 #include <xen/sched.h>
+#include <xen/event.h>
 #include <asm/hvm/ioreq.h>
 #include <asm/hap.h>
 #include <asm/shadow.h>
@@ -159,6 +160,51 @@ static int dm_op_set_pci_link_route(struct domain *d, uint8_t link,
     return 0;
 }
 
+static int dm_op_modified_memory(struct domain *d, xen_pfn_t *first_pfn,
+                                 unsigned int *nr)
+{
+    xen_pfn_t last_pfn = *first_pfn + *nr - 1;
+    unsigned int iter;
+    int rc;
+
+    if ( (*first_pfn > last_pfn) ||
+         (last_pfn > domain_get_maximum_gpfn(d)) )
+        return -EINVAL;
+
+    if ( !paging_mode_log_dirty(d) )
+        return 0;
+
+    iter = 0;
+    rc = 0;
+    while ( iter < *nr )
+    {
+        unsigned long pfn = *first_pfn + iter;
+        struct page_info *page;
+
+        page = get_page_from_gfn(d, pfn, NULL, P2M_UNSHARE);
+        if ( page )
+        {
+            paging_mark_dirty(d, page_to_mfn(page));
+            /* These are most probably not page tables any more */
+            /* don't take a long time and don't die either */
+            sh_remove_shadows(d, _mfn(page_to_mfn(page)), 1, 0);
+            put_page(page);
+        }
+
+        /* Check for continuation if it's not the last interation */
+        if ( (++iter < *nr) && hypercall_preempt_check() )
+        {
+            rc = -ERESTART;
+            break;
+        }
+    }
+
+    *first_pfn += iter;
+    *nr -= iter;
+
+    return rc;
+}
+
 long do_dm_op(domid_t domid,
               unsigned int nr_bufs,
               XEN_GUEST_HANDLE_PARAM(xen_dm_op_buf_t) bufs)
@@ -277,6 +323,14 @@ long do_dm_op(domid_t domid,
         rc = dm_op_set_pci_link_route(d, data->link, data->isa_irq);
         break;
     }
+    case DMOP_modified_memory:
+    {
+        struct xen_dm_op_modified_memory *data =
+            &op.u.modified_memory;
+
+        rc = dm_op_modified_memory(d, &data->first_pfn, &data->nr);
+        break;
+    }
     default:
         rc = -EOPNOTSUPP;
         break;
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 14d3b87..3b2e9d5 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -5368,7 +5368,6 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
     default:
         mask = ~0UL;
         break;
-    case HVMOP_modified_memory:
     case HVMOP_set_mem_type:
         mask = HVMOP_op_mask;
         break;
@@ -5401,65 +5400,6 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
         rc = guest_handle_is_null(arg) ? hvmop_flush_tlb_all() : -EINVAL;
         break;
 
-    case HVMOP_modified_memory:
-    {
-        struct xen_hvm_modified_memory a;
-        struct domain *d;
-
-        if ( copy_from_guest(&a, arg, 1) )
-            return -EFAULT;
-
-        rc = rcu_lock_remote_domain_by_id(a.domid, &d);
-        if ( rc != 0 )
-            return rc;
-
-        rc = -EINVAL;
-        if ( !is_hvm_domain(d) )
-            goto modmem_fail;
-
-        rc = xsm_hvm_control(XSM_DM_PRIV, d, op);
-        if ( rc )
-            goto modmem_fail;
-
-        rc = -EINVAL;
-        if ( a.nr < start_iter ||
-             ((a.first_pfn + a.nr - 1) < a.first_pfn) ||
-             ((a.first_pfn + a.nr - 1) > domain_get_maximum_gpfn(d)) )
-            goto modmem_fail;
-
-        rc = 0;
-        if ( !paging_mode_log_dirty(d) )
-            goto modmem_fail;
-
-        while ( a.nr > start_iter )
-        {
-            unsigned long pfn = a.first_pfn + start_iter;
-            struct page_info *page;
-
-            page = get_page_from_gfn(d, pfn, NULL, P2M_UNSHARE);
-            if ( page )
-            {
-                paging_mark_dirty(d, page_to_mfn(page));
-                /* These are most probably not page tables any more */
-                /* don't take a long time and don't die either */
-                sh_remove_shadows(d, _mfn(page_to_mfn(page)), 1, 0);
-                put_page(page);
-            }
-
-            /* Check for continuation if it's not the last interation */
-            if ( a.nr > ++start_iter && !(start_iter & HVMOP_op_mask) &&
-                 hypercall_preempt_check() )
-            {
-                rc = -ERESTART;
-                break;
-            }
-        }
-
-    modmem_fail:
-        rcu_unlock_domain(d);
-        break;
-    }
-
     case HVMOP_get_mem_type:
         rc = hvmop_get_mem_type(
             guest_handle_cast(arg, xen_hvm_get_mem_type_t));
diff --git a/xen/include/public/hvm/dm_op.h b/xen/include/public/hvm/dm_op.h
index b47014b..d2065f2 100644
--- a/xen/include/public/hvm/dm_op.h
+++ b/xen/include/public/hvm/dm_op.h
@@ -232,6 +232,19 @@ struct xen_dm_op_set_pci_link_route {
     uint8_t  isa_irq;
 };
 
+/*
+ * DMOP_modified_memory: Notify that some pages were modified by an
+ *                       emulator.
+ */
+#define DMOP_modified_memory 11
+
+struct xen_dm_op_modified_memory {
+    /* IN - number of contiguous pages modified */
+    uint32_t nr;
+    /* IN - first pfn modified */
+    uint64_t first_pfn;
+};
+
 
 struct xen_dm_op {
     uint32_t op;
@@ -246,6 +259,7 @@ struct xen_dm_op {
         struct xen_dm_op_set_pci_intx_level set_pci_intx_level;
         struct xen_dm_op_set_isa_irq_level set_isa_irq_level;
         struct xen_dm_op_set_pci_link_route set_pci_link_route;
+        struct xen_dm_op_modified_memory modified_memory;
     } u;
 };
 
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index 1b9e3e0..45879cf 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -118,8 +118,6 @@ struct xen_hvm_track_dirty_vram {
 typedef struct xen_hvm_track_dirty_vram xen_hvm_track_dirty_vram_t;
 DEFINE_XEN_GUEST_HANDLE(xen_hvm_track_dirty_vram_t);
 
-#endif /* __XEN_INTERFACE_VERSION__ < 0x00040900 */
-
 /* Notify that some pages got modified by the Device Model. */
 #define HVMOP_modified_memory    7
 struct xen_hvm_modified_memory {
@@ -133,6 +131,8 @@ struct xen_hvm_modified_memory {
 typedef struct xen_hvm_modified_memory xen_hvm_modified_memory_t;
 DEFINE_XEN_GUEST_HANDLE(xen_hvm_modified_memory_t);
 
+#endif /* __XEN_INTERFACE_VERSION__ < 0x00040900 */
+
 #define HVMOP_set_mem_type    8
 /* Notify that a region of memory is to be treated in a specific way. */
 struct xen_hvm_set_mem_type {
diff --git a/xen/xsm/flask/policy/access_vectors b/xen/xsm/flask/policy/access_vectors
index 708cfe6..2041ca5 100644
--- a/xen/xsm/flask/policy/access_vectors
+++ b/xen/xsm/flask/policy/access_vectors
@@ -260,7 +260,7 @@ class hvm
     bind_irq
 # XEN_DOMCTL_pin_mem_cacheattr
     cacheattr
-# HVMOP_modified_memory, HVMOP_get_mem_type, HVMOP_set_mem_type,
+# HVMOP_get_mem_type, HVMOP_set_mem_type,
 # HVMOP_set_mem_access, HVMOP_get_mem_access, HVMOP_pagetable_dying,
 # HVMOP_inject_trap
     hvmctl
-- 
2.1.4


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