Handle dynamic IOMMU map/unmap for guests

Perform IOMMU map/unmap when (a) frame type changes, (b) memory
reservation changes, and (c) a grant reference is newly mapped or
completely unmapped from a domain.

Signed-off-by: Espen Skoglund <espen.skoglund@netronome.com>

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 879ce9cb17ad4570e5969f68b5dacd3f0d40145c..1ee784230c3c3711f2c869aeab051cd7278ad5e1 100644 (file)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -1939,6 +1939,20 @@ int get_page_type(struct page_info *page, unsigned long type)
     }
     while ( unlikely((y = cmpxchg(&page->u.inuse.type_info, x, nx)) != x) );
 
+    if ( unlikely((x & PGT_type_mask) != type) )
+    {
+        /* Special pages should not be accessible from devices. */
+        struct domain *d = page_get_owner(page);
+        if ( d && unlikely(need_iommu(d)) )
+        {
+            if ( (x & PGT_type_mask) == PGT_writable_page )
+                iommu_unmap_page(d, mfn_to_gmfn(d, page_to_mfn(page)));
+            else if ( type == PGT_writable_page )
+                iommu_map_page(d, mfn_to_gmfn(d, page_to_mfn(page)),
+                               page_to_mfn(page));
+        }
+    }
+
     if ( unlikely(!(nx & PGT_validated)) )
     {
         /* Try to validate page type; drop the new reference on failure. */

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 853ba415d4b6eb705526537dae014a4b7843c78d..c1302f3f1fd7a677d3d3607a27df40c5bac82f29 100644 (file)
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -325,7 +325,7 @@ p2m_set_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
     if ( mfn_valid(mfn) && (gfn > d->arch.p2m->max_mapped_pfn) )
         d->arch.p2m->max_mapped_pfn = gfn;
 
-    if ( iommu_enabled && is_hvm_domain(d) )
+    if ( iommu_enabled && (is_hvm_domain(d) || need_iommu(d)) )
     {
         if ( p2mt == p2m_ram_rw )
             for ( i = 0; i < (1UL << page_order); i++ )
@@ -868,7 +868,12 @@ p2m_remove_page(struct domain *d, unsigned long gfn, unsigned long mfn,
     unsigned long i;
 
     if ( !paging_mode_translate(d) )
+    {
+        if ( need_iommu(d) )
+            for ( i = 0; i < (1 << page_order); i++ )
+                iommu_unmap_page(d, mfn + i);
         return;
+    }
 
     P2M_DEBUG("removing gfn=%#lx mfn=%#lx\n", gfn, mfn);
 
@@ -899,7 +904,19 @@ guest_physmap_add_entry(struct domain *d, unsigned long gfn,
     int rc = 0;
 
     if ( !paging_mode_translate(d) )
-        return -EINVAL;
+    {
+        if ( need_iommu(d) && t == p2m_ram_rw )
+        {
+            for ( i = 0; i < (1 << page_order); i++ )
+                if ( (rc = iommu_map_page(d, mfn + i, mfn + i)) != 0 )
+                {
+                    while ( i-- > 0 )
+                        iommu_unmap_page(d, mfn + i);
+                    return rc;
+                }
+        }
+        return 0;
+    }
 
 #if CONFIG_PAGING_LEVELS == 3
     /*

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 879132ce1b8841b2f6bf6f6cb1451132a2177fd9..de3af2b8ed352d181b35a190cb4fc74a696113bb 100644 (file)
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -196,8 +196,9 @@ __gnttab_map_grant_ref(
     struct domain *ld, *rd;
     struct vcpu   *led;
     int            handle;
-    unsigned long  frame = 0;
+    unsigned long  frame = 0, nr_gets = 0;
     int            rc = GNTST_okay;
+    u32            old_pin;
     unsigned int   cache_flags;
     struct active_grant_entry *act;
     struct grant_mapping *mt;
@@ -318,6 +319,7 @@ __gnttab_map_grant_ref(
         }
     }
 
+    old_pin = act->pin;
     if ( op->flags & GNTMAP_device_map )
         act->pin += (op->flags & GNTMAP_readonly) ?
             GNTPIN_devr_inc : GNTPIN_devw_inc;
@@ -361,20 +363,17 @@ __gnttab_map_grant_ref(
             rc = GNTST_general_error;
             goto undo_out;
         }
-        
+
+        nr_gets++;
         if ( op->flags & GNTMAP_host_map )
         {
             rc = create_grant_host_mapping(op->host_addr, frame, op->flags, 0);
             if ( rc != GNTST_okay )
-            {
-                if ( gnttab_host_mapping_get_page_type(op, ld, rd) )
-                    put_page_type(mfn_to_page(frame));
-                put_page(mfn_to_page(frame));
                 goto undo_out;
-            }
 
             if ( op->flags & GNTMAP_device_map )
             {
+                nr_gets++;
                 (void)get_page(mfn_to_page(frame), rd);
                 if ( !(op->flags & GNTMAP_readonly) )
                     get_page_type(mfn_to_page(frame), PGT_writable_page);
@@ -382,6 +381,17 @@ __gnttab_map_grant_ref(
         }
     }
 
+    if ( need_iommu(ld) &&
+         !(old_pin & (GNTPIN_hstw_mask|GNTPIN_devw_mask)) &&
+         (act->pin & (GNTPIN_hstw_mask|GNTPIN_devw_mask)) )
+    {
+        if ( iommu_map_page(ld, mfn_to_gmfn(ld, frame), frame) )
+        {
+            rc = GNTST_general_error;
+            goto undo_out;
+        }
+    }
+
     TRACE_1D(TRC_MEM_PAGE_GRANT_MAP, op->dom);
 
     mt = &maptrack_entry(ld->grant_table, handle);
@@ -397,6 +407,19 @@ __gnttab_map_grant_ref(
     return;
 
  undo_out:
+    if ( nr_gets > 1 )
+    {
+        if ( !(op->flags & GNTMAP_readonly) )
+            put_page_type(mfn_to_page(frame));
+        put_page(mfn_to_page(frame));
+    }
+    if ( nr_gets > 0 )
+    {
+        if ( gnttab_host_mapping_get_page_type(op, ld, rd) )
+            put_page_type(mfn_to_page(frame));
+        put_page(mfn_to_page(frame));
+    }
+
     spin_lock(&rd->grant_table->lock);
 
     act = &active_entry(rd->grant_table, op->ref);
@@ -451,6 +474,7 @@ __gnttab_unmap_common(
     struct active_grant_entry *act;
     grant_entry_t   *sha;
     s16              rc = 0;
+    u32              old_pin;
 
     ld = current->domain;
 
@@ -497,6 +521,7 @@ __gnttab_unmap_common(
 
     act = &active_entry(rd->grant_table, op->map->ref);
     sha = &shared_entry(rd->grant_table, op->map->ref);
+    old_pin = act->pin;
 
     if ( op->frame == 0 )
     {
@@ -534,6 +559,17 @@ __gnttab_unmap_common(
             act->pin -= GNTPIN_hstw_inc;
     }
 
+    if ( need_iommu(ld) &&
+         (old_pin & (GNTPIN_hstw_mask|GNTPIN_devw_mask)) &&
+         !(act->pin & (GNTPIN_hstw_mask|GNTPIN_devw_mask)) )
+    {
+        if ( iommu_unmap_page(ld, mfn_to_gmfn(ld, op->frame)) )
+        {
+            rc = GNTST_general_error;
+            goto unmap_out;
+        }
+    }
+
     /* If just unmapped a writable mapping, mark as dirtied */
     if ( !(op->flags & GNTMAP_readonly) )
          gnttab_mark_dirty(rd, op->frame);

diff --git a/xen/common/memory.c b/xen/common/memory.c
index cc9d1851a7bf4cc38b5e5873c6937ed64546036a..58f138939fedf9ebd432536e8878800810b0fdd0 100644 (file)
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -124,12 +124,9 @@ static void populate_physmap(struct memop_args *a)
         }
 
         mfn = page_to_mfn(page);
+        guest_physmap_add_page(d, gpfn, mfn, a->extent_order);
 
-        if ( unlikely(paging_mode_translate(d)) )
-        {
-            guest_physmap_add_page(d, gpfn, mfn, a->extent_order);
-        }
-        else
+        if ( !paging_mode_translate(d) )
         {
             for ( j = 0; j < (1 << a->extent_order); j++ )
                 set_gpfn_from_mfn(mfn + j, gpfn + j);
@@ -436,11 +433,9 @@ static long memory_exchange(XEN_GUEST_HANDLE(xen_memory_exchange_t) arg)
                 &gpfn, exch.out.extent_start, (i<<out_chunk_order)+j, 1);
 
             mfn = page_to_mfn(page);
-            if ( unlikely(paging_mode_translate(d)) )
-            {
-                guest_physmap_add_page(d, gpfn, mfn, exch.out.extent_order);
-            }
-            else
+            guest_physmap_add_page(d, gpfn, mfn, exch.out.extent_order);
+
+            if ( !paging_mode_translate(d) )
             {
                 for ( k = 0; k < (1UL << exch.out.extent_order); k++ )
                     set_gpfn_from_mfn(mfn + k, gpfn + k);