KVM: MMU: Convert the paging mode shadow walk to use the generic walker

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 86 insertions, 72 deletions

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index ebb26a09d311..b7064e1e1e17 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -25,6 +25,7 @@
 #if PTTYPE == 64
         #define pt_element_t u64
         #define guest_walker guest_walker64
+        #define shadow_walker shadow_walker64
         #define FNAME(name) paging##64_##name
         #define PT_BASE_ADDR_MASK PT64_BASE_ADDR_MASK
         #define PT_DIR_BASE_ADDR_MASK PT64_DIR_BASE_ADDR_MASK
@@ -41,6 +42,7 @@
 #elif PTTYPE == 32
         #define pt_element_t u32
         #define guest_walker guest_walker32
+        #define shadow_walker shadow_walker32
         #define FNAME(name) paging##32_##name
         #define PT_BASE_ADDR_MASK PT32_BASE_ADDR_MASK
         #define PT_DIR_BASE_ADDR_MASK PT32_DIR_BASE_ADDR_MASK
@@ -71,6 +73,17 @@ struct guest_walker {
         u32 error_code;
 };
 
+struct shadow_walker {
+        struct kvm_shadow_walk walker;
+        struct guest_walker *guest_walker;
+        int user_fault;
+        int write_fault;
+        int largepage;
+        int *ptwrite;
+        pfn_t pfn;
+        u64 *sptep;
+};
+
 static gfn_t gpte_to_gfn(pt_element_t gpte)
 {
         return (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
@@ -272,86 +285,86 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
 /*
  * Fetch a shadow pte for a specific level in the paging hierarchy.
  */
-static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
-                         struct guest_walker *walker,
-                         int user_fault, int write_fault, int largepage,
-                         int *ptwrite, pfn_t pfn)
+static int FNAME(shadow_walk_entry)(struct kvm_shadow_walk *_sw,
+                                    struct kvm_vcpu *vcpu, gva_t addr,
+                                    u64 *sptep, int level)
 {
-        hpa_t shadow_addr;
-        int level;
-        u64 *shadow_ent;
-        unsigned access = walker->pt_access;
-
-        if (!is_present_pte(walker->ptes[walker->level - 1]))
-                return NULL;
-
-        shadow_addr = vcpu->arch.mmu.root_hpa;
-        level = vcpu->arch.mmu.shadow_root_level;
-        if (level == PT32E_ROOT_LEVEL) {
-                shadow_addr = vcpu->arch.mmu.pae_root[(addr >> 30) & 3];
-                shadow_addr &= PT64_BASE_ADDR_MASK;
-                --level;
+        struct shadow_walker *sw =
+                container_of(_sw, struct shadow_walker, walker);
+        struct guest_walker *gw = sw->guest_walker;
+        unsigned access = gw->pt_access;
+        struct kvm_mmu_page *shadow_page;
+        u64 spte;
+        int metaphysical;
+        gfn_t table_gfn;
+        int r;
+        pt_element_t curr_pte;
+
+        if (level == PT_PAGE_TABLE_LEVEL
+            || (sw->largepage && level == PT_DIRECTORY_LEVEL)) {
+                mmu_set_spte(vcpu, sptep, access, gw->pte_access & access,
+                             sw->user_fault, sw->write_fault,
+                             gw->ptes[gw->level-1] & PT_DIRTY_MASK,
+                             sw->ptwrite, sw->largepage, gw->gfn, sw->pfn,
+                             false);
+                sw->sptep = sptep;
+                return 1;
         }
 
-        for (; ; level--) {
-                u32 index = SHADOW_PT_INDEX(addr, level);
-                struct kvm_mmu_page *shadow_page;
-                u64 shadow_pte;
-                int metaphysical;
-                gfn_t table_gfn;
-
-                shadow_ent = ((u64 *)__va(shadow_addr)) + index;
-                if (level == PT_PAGE_TABLE_LEVEL)
-                        break;
-
-                if (largepage && level == PT_DIRECTORY_LEVEL)
-                        break;
-
-                if (is_shadow_present_pte(*shadow_ent)
-                    && !is_large_pte(*shadow_ent)) {
-                        shadow_addr = *shadow_ent & PT64_BASE_ADDR_MASK;
-                        continue;
-                }
+        if (is_shadow_present_pte(*sptep) && !is_large_pte(*sptep))
+                return 0;
 
-                if (is_large_pte(*shadow_ent))
-                        rmap_remove(vcpu->kvm, shadow_ent);
-
-                if (level - 1 == PT_PAGE_TABLE_LEVEL
-                    && walker->level == PT_DIRECTORY_LEVEL) {
-                        metaphysical = 1;
-                        if (!is_dirty_pte(walker->ptes[level - 1]))
-                                access &= ~ACC_WRITE_MASK;
-                        table_gfn = gpte_to_gfn(walker->ptes[level - 1]);
-                } else {
-                        metaphysical = 0;
-                        table_gfn = walker->table_gfn[level - 2];
-                }
-                shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
-                                               metaphysical, access,
-                                               shadow_ent);
-                if (!metaphysical) {
-                        int r;
-                        pt_element_t curr_pte;
-                        r = kvm_read_guest_atomic(vcpu->kvm,
-                                                  walker->pte_gpa[level - 2],
-                                                  &curr_pte, sizeof(curr_pte));
-                        if (r || curr_pte != walker->ptes[level - 2]) {
-                                kvm_release_pfn_clean(pfn);
-                                return NULL;
-                        }
+        if (is_large_pte(*sptep))
+                rmap_remove(vcpu->kvm, sptep);
+
+        if (level == PT_DIRECTORY_LEVEL && gw->level == PT_DIRECTORY_LEVEL) {
+                metaphysical = 1;
+                if (!is_dirty_pte(gw->ptes[level - 1]))
+                        access &= ~ACC_WRITE_MASK;
+                table_gfn = gpte_to_gfn(gw->ptes[level - 1]);
+        } else {
+                metaphysical = 0;
+                table_gfn = gw->table_gfn[level - 2];
+        }
+        shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
+                                       metaphysical, access, sptep);
+        if (!metaphysical) {
+                r = kvm_read_guest_atomic(vcpu->kvm, gw->pte_gpa[level - 2],
+                                          &curr_pte, sizeof(curr_pte));
+                if (r || curr_pte != gw->ptes[level - 2]) {
+                        kvm_release_pfn_clean(sw->pfn);
+                        sw->sptep = NULL;
+                        return 1;
                 }
-                shadow_addr = __pa(shadow_page->spt);
-                shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK
-                        | PT_WRITABLE_MASK | PT_USER_MASK;
-                set_shadow_pte(shadow_ent, shadow_pte);
         }
 
-        mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access,
-                     user_fault, write_fault,
-                     walker->ptes[walker->level-1] & PT_DIRTY_MASK,
-                     ptwrite, largepage, walker->gfn, pfn, false);
+        spte = __pa(shadow_page->spt) | PT_PRESENT_MASK | PT_ACCESSED_MASK
+                | PT_WRITABLE_MASK | PT_USER_MASK;
+        *sptep = spte;
+        return 0;
+}
+
+static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
+                         struct guest_walker *guest_walker,
+                         int user_fault, int write_fault, int largepage,
+                         int *ptwrite, pfn_t pfn)
+{
+        struct shadow_walker walker = {
+                .walker = { .entry = FNAME(shadow_walk_entry), },
+                .guest_walker = guest_walker,
+                .user_fault = user_fault,
+                .write_fault = write_fault,
+                .largepage = largepage,
+                .ptwrite = ptwrite,
+                .pfn = pfn,
+        };
+
+        if (!is_present_pte(guest_walker->ptes[guest_walker->level - 1]))
+                return NULL;
+
+        walk_shadow(&walker.walker, vcpu, addr);
 
-        return shadow_ent;
+        return walker.sptep;
 }
 
 /*
@@ -499,6 +512,7 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
 
 #undef pt_element_t
 #undef guest_walker
+#undef shadow_walker
 #undef FNAME
 #undef PT_BASE_ADDR_MASK
 #undef PT_INDEX