[Xen-devel] [PATCH 19/20] x86/shadow: Alter sh_remove_write_access to take a domain

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

This allows the removal an improper use of d->vcpu[0] from toolstack context

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Tim Deegan <tim@xxxxxxx>
---
 xen/arch/x86/mm/shadow/common.c  |    7 +++----
 xen/arch/x86/mm/shadow/multi.c   |   16 ++++++----------
 xen/arch/x86/mm/shadow/private.h |    2 +-
 3 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index d24859e..4e6397a 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -671,7 +671,7 @@ static int oos_remove_write_access(struct vcpu *v, mfn_t 
gmfn,
 
     ftlb |= oos_fixup_flush_gmfn(v, gmfn, fixup);
 
-    switch ( sh_remove_write_access(v, gmfn, 0, 0) )
+    switch ( sh_remove_write_access(d, gmfn, 0, 0) )
     {
     default:
     case 0:
@@ -2180,7 +2180,7 @@ static inline void trace_shadow_wrmap_bf(mfn_t gmfn)
  * level==0 means we have some other reason for revoking write access.
  * If level==0 we are allowed to fail, returning -1. */
 
-int sh_remove_write_access(struct vcpu *v, mfn_t gmfn,
+int sh_remove_write_access(struct domain *d, mfn_t gmfn,
                            unsigned int level,
                            unsigned long fault_addr)
 {
@@ -2212,7 +2212,6 @@ int sh_remove_write_access(struct vcpu *v, mfn_t gmfn,
         | SHF_L1_64
         | SHF_FL1_64
         ;
-    struct domain *d = v->domain;
     struct page_info *pg = mfn_to_page(gmfn);
 #if SHADOW_OPTIMIZATIONS & SHOPT_WRITABLE_HEURISTIC
     struct vcpu *curr = current;
@@ -3689,7 +3688,7 @@ int shadow_track_dirty_vram(struct domain *d,
                 for ( i = begin_pfn; i < end_pfn; i++ ) {
                     mfn_t mfn = get_gfn_query_unlocked(d, i, &t);
                     if (mfn_x(mfn) != INVALID_MFN)
-                        flush_tlb |= sh_remove_write_access(d->vcpu[0], mfn, 
1, 0);
+                        flush_tlb |= sh_remove_write_access(d, mfn, 1, 0);
                 }
                 dirty_vram->last_dirty = -1;
             }
diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index 288c7d5..16cd60d 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -278,11 +278,7 @@ shadow_check_gl1e(struct vcpu *v, walk_t *gw)
 static inline uint32_t
 gw_remove_write_accesses(struct vcpu *v, unsigned long va, walk_t *gw)
 {
-#if GUEST_PAGING_LEVELS >= 3 /* PAE or 64... */
-#if (SHADOW_OPTIMIZATIONS & SHOPT_OUT_OF_SYNC)
     struct domain *d = v->domain;
-#endif
-#endif
     uint32_t rc = 0;
 
 #if GUEST_PAGING_LEVELS >= 3 /* PAE or 64... */
@@ -295,7 +291,7 @@ gw_remove_write_accesses(struct vcpu *v, unsigned long va, 
walk_t *gw)
     }
     else
 #endif /* OOS */
-     if ( sh_remove_write_access(v, gw->l3mfn, 3, va) )
+     if ( sh_remove_write_access(d, gw->l3mfn, 3, va) )
          rc = GW_RMWR_FLUSHTLB;
 #endif /* GUEST_PAGING_LEVELS >= 4 */
 
@@ -307,7 +303,7 @@ gw_remove_write_accesses(struct vcpu *v, unsigned long va, 
walk_t *gw)
     }
     else
 #endif /* OOS */
-    if ( sh_remove_write_access(v, gw->l2mfn, 2, va) )
+    if ( sh_remove_write_access(d, gw->l2mfn, 2, va) )
         rc |= GW_RMWR_FLUSHTLB;
 #endif /* GUEST_PAGING_LEVELS >= 3 */
 
@@ -316,7 +312,7 @@ gw_remove_write_accesses(struct vcpu *v, unsigned long va, 
walk_t *gw)
 #if (SHADOW_OPTIMIZATIONS & SHOPT_OUT_OF_SYNC)
          && !mfn_is_out_of_sync(gw->l1mfn)
 #endif /* OOS */
-         && sh_remove_write_access(v, gw->l1mfn, 1, va) )
+         && sh_remove_write_access(d, gw->l1mfn, 1, va) )
         rc |= GW_RMWR_FLUSHTLB;
 
     return rc;
@@ -4028,7 +4024,7 @@ sh_update_cr3(struct vcpu *v, int do_locking)
      * replace the old shadow pagetable(s), so that we can safely use the
      * (old) shadow linear maps in the writeable mapping heuristics. */
 #if GUEST_PAGING_LEVELS == 2
-    if ( sh_remove_write_access(v, gmfn, 2, 0) != 0 )
+    if ( sh_remove_write_access(d, gmfn, 2, 0) != 0 )
         flush_tlb_mask(d->domain_dirty_cpumask);
     sh_set_toplevel_shadow(v, 0, gmfn, SH_type_l2_shadow);
 #elif GUEST_PAGING_LEVELS == 3
@@ -4048,7 +4044,7 @@ sh_update_cr3(struct vcpu *v, int do_locking)
                 gl2gfn = guest_l3e_get_gfn(gl3e[i]);
                 gl2mfn = get_gfn_query_unlocked(d, gfn_x(gl2gfn), &p2mt);
                 if ( p2m_is_ram(p2mt) )
-                    flush |= sh_remove_write_access(v, gl2mfn, 2, 0);
+                    flush |= sh_remove_write_access(d, gl2mfn, 2, 0);
             }
         }
         if ( flush )
@@ -4072,7 +4068,7 @@ sh_update_cr3(struct vcpu *v, int do_locking)
         }
     }
 #elif GUEST_PAGING_LEVELS == 4
-    if ( sh_remove_write_access(v, gmfn, 4, 0) != 0 )
+    if ( sh_remove_write_access(d, gmfn, 4, 0) != 0 )
         flush_tlb_mask(d->domain_dirty_cpumask);
     sh_set_toplevel_shadow(v, 0, gmfn, SH_type_l4_shadow);
 #else
diff --git a/xen/arch/x86/mm/shadow/private.h b/xen/arch/x86/mm/shadow/private.h
index 96b53b9..1bf1deb 100644
--- a/xen/arch/x86/mm/shadow/private.h
+++ b/xen/arch/x86/mm/shadow/private.h
@@ -374,7 +374,7 @@ void sh_validate_guest_pt_write(struct vcpu *v, mfn_t gmfn,
  * Returns non-zero if we need to flush TLBs.
  * level and fault_addr desribe how we found this to be a pagetable;
  * level==0 means we have some other reason for revoking write access. */
-extern int sh_remove_write_access(struct vcpu *v, mfn_t readonly_mfn,
+extern int sh_remove_write_access(struct domain *d, mfn_t readonly_mfn,
                                   unsigned int level,
                                   unsigned long fault_addr);
 
-- 
1.7.10.4


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