Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linux
[cascardo/linux.git] / arch / x86 / kvm / paging_tmpl.h
index 714e2c0..891eb6d 100644 (file)
@@ -305,51 +305,43 @@ 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)
+static bool
+FNAME(prefetch_gpte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp,
+                    u64 *spte, pt_element_t gpte, bool no_dirty_log)
 {
-       if (is_rsvd_bits_set(&vcpu->arch.mmu, gpte, PT_PAGE_TABLE_LEVEL))
-               goto no_present;
-
-       if (!is_present_gpte(gpte))
-               goto no_present;
-
-       if (!(gpte & PT_ACCESSED_MASK))
-               goto no_present;
-
-       return false;
-
-no_present:
-       drop_spte(vcpu->kvm, spte);
-       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;
+       gfn_t gfn;
        pfn_t pfn;
 
-       gpte = *(const pt_element_t *)pte;
-       if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte))
-               return;
+       if (prefetch_invalid_gpte(vcpu, sp, spte, gpte))
+               return false;
 
        pgprintk("%s: gpte %llx spte %p\n", __func__, (u64)gpte, spte);
+
+       gfn = gpte_to_gfn(gpte);
        pte_access = sp->role.access & gpte_access(vcpu, gpte);
        protect_clean_gpte(&pte_access, gpte);
-       pfn = gfn_to_pfn_atomic(vcpu->kvm, gpte_to_gfn(gpte));
-       if (mmu_invalid_pfn(pfn))
-               return;
+       pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,
+                       no_dirty_log && (pte_access & ACC_WRITE_MASK));
+       if (is_error_pfn(pfn))
+               return false;
 
        /*
-        * we call mmu_set_spte() with host_writable = true because that
-        * vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1).
+        * we call mmu_set_spte() with host_writable = true because
+        * pte_prefetch_gfn_to_pfn always gets a writable pfn.
         */
        mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,
-                    NULL, PT_PAGE_TABLE_LEVEL,
-                    gpte_to_gfn(gpte), pfn, true, true);
+                    NULL, PT_PAGE_TABLE_LEVEL, gfn, pfn, true, true);
+
+       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 = *(const pt_element_t *)pte;
+
+       FNAME(prefetch_gpte)(vcpu, sp, spte, gpte, false);
 }
 
 static bool FNAME(gpte_changed)(struct kvm_vcpu *vcpu,
@@ -395,53 +387,34 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
        spte = sp->spt + i;
 
        for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) {
-               pt_element_t gpte;
-               unsigned pte_access;
-               gfn_t gfn;
-               pfn_t pfn;
-
                if (spte == sptep)
                        continue;
 
                if (is_shadow_present_pte(*spte))
                        continue;
 
-               gpte = gptep[i];
-
-               if (FNAME(prefetch_invalid_gpte)(vcpu, sp, spte, gpte))
-                       continue;
-
-               pte_access = sp->role.access & gpte_access(vcpu, gpte);
-               protect_clean_gpte(&pte_access, gpte);
-               gfn = gpte_to_gfn(gpte);
-               pfn = pte_prefetch_gfn_to_pfn(vcpu, gfn,
-                                     pte_access & ACC_WRITE_MASK);
-               if (mmu_invalid_pfn(pfn))
+               if (!FNAME(prefetch_gpte)(vcpu, sp, spte, gptep[i], true))
                        break;
-
-               mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0,
-                            NULL, PT_PAGE_TABLE_LEVEL, gfn,
-                            pfn, true, true);
        }
 }
 
 /*
  * Fetch a shadow pte for a specific level in the paging hierarchy.
+ * If the guest tries to write a write-protected page, we need to
+ * emulate this operation, return 1 to indicate this case.
  */
-static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
+static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                         struct guest_walker *gw,
                         int user_fault, int write_fault, int hlevel,
-                        int *emulate, pfn_t pfn, bool map_writable,
-                        bool prefault)
+                        pfn_t pfn, bool map_writable, bool prefault)
 {
-       unsigned access = gw->pt_access;
        struct kvm_mmu_page *sp = NULL;
-       int top_level;
-       unsigned direct_access;
        struct kvm_shadow_walk_iterator it;
+       unsigned direct_access, access = gw->pt_access;
+       int top_level, emulate = 0;
 
        if (!is_present_gpte(gw->ptes[gw->level - 1]))
-               return NULL;
+               return 0;
 
        direct_access = gw->pte_access;
 
@@ -505,17 +478,17 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 
        clear_sp_write_flooding_count(it.sptep);
        mmu_set_spte(vcpu, it.sptep, access, gw->pte_access,
-                    user_fault, write_fault, emulate, it.level,
+                    user_fault, write_fault, &emulate, it.level,
                     gw->gfn, pfn, prefault, map_writable);
        FNAME(pte_prefetch)(vcpu, gw, it.sptep);
 
-       return it.sptep;
+       return emulate;
 
 out_gpte_changed:
        if (sp)
                kvm_mmu_put_page(sp, it.sptep);
        kvm_release_pfn_clean(pfn);
-       return NULL;
+       return 0;
 }
 
 /*
@@ -538,8 +511,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
        int write_fault = error_code & PFERR_WRITE_MASK;
        int user_fault = error_code & PFERR_USER_MASK;
        struct guest_walker walker;
-       u64 *sptep;
-       int emulate = 0;
        int r;
        pfn_t pfn;
        int level = PT_PAGE_TABLE_LEVEL;
@@ -594,24 +565,20 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
                return r;
 
        spin_lock(&vcpu->kvm->mmu_lock);
-       if (mmu_notifier_retry(vcpu, mmu_seq))
+       if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
                goto out_unlock;
 
        kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);
        kvm_mmu_free_some_pages(vcpu);
        if (!force_pt_level)
                transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);
-       sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
-                            level, &emulate, pfn, map_writable, prefault);
-       (void)sptep;
-       pgprintk("%s: shadow pte %p %llx emulate %d\n", __func__,
-                sptep, *sptep, emulate);
-
+       r = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
+                        level, pfn, map_writable, prefault);
        ++vcpu->stat.pf_fixed;
        kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
        spin_unlock(&vcpu->kvm->mmu_lock);
 
-       return emulate;
+       return r;
 
 out_unlock:
        spin_unlock(&vcpu->kvm->mmu_lock);
@@ -757,7 +724,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp)
                                          sizeof(pt_element_t)))
                        return -EINVAL;
 
-               if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) {
+               if (prefetch_invalid_gpte(vcpu, sp, &sp->spt[i], gpte)) {
                        vcpu->kvm->tlbs_dirty++;
                        continue;
                }