KVM: MMU: abstract invalid guest pte mapping
Xiao Guangrong [Tue, 23 Nov 2010 03:08:42 +0000 (11:08 +0800)]
Introduce a common function to map invalid gpte

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/mmu.c
arch/x86/kvm/paging_tmpl.h

index 3db0cd4..53ff31f 100644 (file)
@@ -3075,9 +3075,6 @@ static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu,
                return;
         }
 
-       if (is_rsvd_bits_set(&vcpu->arch.mmu, *(u64 *)new, PT_PAGE_TABLE_LEVEL))
-               return;
-
        ++vcpu->kvm->stat.mmu_pte_updated;
        if (!sp->role.cr4_pae)
                paging32_update_pte(vcpu, sp, spte, new);
index 60f00db..a43f4cc 100644 (file)
@@ -299,25 +299,42 @@ static int FNAME(walk_addr_nested)(struct guest_walker *walker,
                                        addr, access);
 }
 
+static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu,
+                                   struct kvm_mmu_page *sp, u64 *spte,
+                                   pt_element_t gpte)
+{
+       u64 nonpresent = shadow_trap_nonpresent_pte;
+
+       if (is_rsvd_bits_set(&vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL))
+               goto no_present;
+
+       if (!is_present_gpte(gpte)) {
+               if (!sp->unsync)
+                       nonpresent = shadow_notrap_nonpresent_pte;
+               goto no_present;
+       }
+
+       if (!(gpte & PT_ACCESSED_MASK))
+               goto no_present;
+
+       return false;
+
+no_present:
+       drop_spte(vcpu->kvm, spte, nonpresent);
+       return true;
+}
+
 static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
                              u64 *spte, const void *pte)
 {
        pt_element_t gpte;
        unsigned pte_access;
        pfn_t pfn;
-       u64 new_spte;
 
        gpte = *(const pt_element_t *)pte;
-       if (~gpte & (PT_PRESENT_MASK | PT_ACCESSED_MASK)) {
-               if (!is_present_gpte(gpte)) {
-                       if (sp->unsync)
-                               new_spte = shadow_trap_nonpresent_pte;
-                       else
-                               new_spte = shadow_notrap_nonpresent_pte;
-                       __set_spte(spte, new_spte);
-               }
+       if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte))
                return;
-       }
+
        pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
        pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
        if (gpte_to_gfn(gpte) != vcpu->arch.update_pte.gfn)
@@ -364,7 +381,6 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
                                u64 *sptep)
 {
        struct kvm_mmu_page *sp;
-       struct kvm_mmu *mmu = &vcpu->arch.mmu;
        pt_element_t *gptep = gw->prefetch_ptes;
        u64 *spte;
        int i;
@@ -395,16 +411,7 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
 
                gpte = gptep[i];
 
-               if (is_rsvd_bits_set(mmu, gpte, PT_PAGE_TABLE_LEVEL))
-                       continue;
-
-               if (!is_present_gpte(gpte)) {
-                       if (!sp->unsync)
-                               __set_spte(spte, shadow_notrap_nonpresent_pte);
-                       continue;
-               }
-
-               if (!(gpte & PT_ACCESSED_MASK))
+               if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte))
                        continue;
 
                pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
@@ -761,7 +768,6 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
                pt_element_t gpte;
                gpa_t pte_gpa;
                gfn_t gfn;
-               bool rsvd_bits_set;
 
                if (!is_shadow_present_pte(sp->spt[i]))
                        continue;
@@ -773,18 +779,15 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
                        return -EINVAL;
 
                gfn = gpte_to_gfn(gpte);
-               rsvd_bits_set = is_rsvd_bits_set(&vcpu->arch.mmu, gpte,
-                                                PT_PAGE_TABLE_LEVEL);
-               if (rsvd_bits_set || gfn != sp->gfns[i] ||
-                     !is_present_gpte(gpte) || !(gpte & PT_ACCESSED_MASK)) {
-                       u64 nonpresent;
-
-                       if (rsvd_bits_set || is_present_gpte(gpte) ||
-                             sp->unsync)
-                               nonpresent = shadow_trap_nonpresent_pte;
-                       else
-                               nonpresent = shadow_notrap_nonpresent_pte;
-                       drop_spte(vcpu->kvm, &sp->spt[i], nonpresent);
+
+               if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) {
+                       kvm_flush_remote_tlbs(vcpu->kvm);
+                       continue;
+               }
+
+               if (gfn != sp->gfns[i]) {
+                       drop_spte(vcpu->kvm, &sp->spt[i],
+                                     shadow_trap_nonpresent_pte);
                        kvm_flush_remote_tlbs(vcpu->kvm);
                        continue;
                }