KVM: MMU: rename is_largepage_backed to mapping_level

With the new name and the corresponding backend changes this function
can now support multiple hugepage sizes.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 67 insertions, 33 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index b93ad2c79c15..c707936b2414 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -393,37 +393,52 @@ static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
  * Return the pointer to the largepage write count for a given
  * gfn, handling slots that are not large page aligned.
  */
-static int *slot_largepage_idx(gfn_t gfn, struct kvm_memory_slot *slot)
+static int *slot_largepage_idx(gfn_t gfn,
+                               struct kvm_memory_slot *slot,
+                               int level)
 {
         unsigned long idx;
 
-        idx = (gfn / KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL)) -
-              (slot->base_gfn / KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL));
-        return &slot->lpage_info[0][idx].write_count;
+        idx = (gfn / KVM_PAGES_PER_HPAGE(level)) -
+              (slot->base_gfn / KVM_PAGES_PER_HPAGE(level));
+        return &slot->lpage_info[level - 2][idx].write_count;
 }
 
 static void account_shadowed(struct kvm *kvm, gfn_t gfn)
 {
+        struct kvm_memory_slot *slot;
         int *write_count;
+        int i;
 
         gfn = unalias_gfn(kvm, gfn);
-        write_count = slot_largepage_idx(gfn,
-                                         gfn_to_memslot_unaliased(kvm, gfn));
-        *write_count += 1;
+
+        slot = gfn_to_memslot_unaliased(kvm, gfn);
+        for (i = PT_DIRECTORY_LEVEL;
+             i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+                write_count   = slot_largepage_idx(gfn, slot, i);
+                *write_count += 1;
+        }
 }
 
 static void unaccount_shadowed(struct kvm *kvm, gfn_t gfn)
 {
+        struct kvm_memory_slot *slot;
         int *write_count;
+        int i;
 
         gfn = unalias_gfn(kvm, gfn);
-        write_count = slot_largepage_idx(gfn,
-                                         gfn_to_memslot_unaliased(kvm, gfn));
-        *write_count -= 1;
-        WARN_ON(*write_count < 0);
+        for (i = PT_DIRECTORY_LEVEL;
+             i < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++i) {
+                slot          = gfn_to_memslot_unaliased(kvm, gfn);
+                write_count   = slot_largepage_idx(gfn, slot, i);
+                *write_count -= 1;
+                WARN_ON(*write_count < 0);
+        }
 }
 
-static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn)
+static int has_wrprotected_page(struct kvm *kvm,
+                                gfn_t gfn,
+                                int level)
 {
         struct kvm_memory_slot *slot;
         int *largepage_idx;
@@ -431,47 +446,67 @@ static int has_wrprotected_page(struct kvm *kvm, gfn_t gfn)
         gfn = unalias_gfn(kvm, gfn);
         slot = gfn_to_memslot_unaliased(kvm, gfn);
         if (slot) {
-                largepage_idx = slot_largepage_idx(gfn, slot);
+                largepage_idx = slot_largepage_idx(gfn, slot, level);
                 return *largepage_idx;
         }
 
         return 1;
 }
 
-static int host_largepage_backed(struct kvm *kvm, gfn_t gfn)
+static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
 {
+        unsigned long page_size = PAGE_SIZE;
         struct vm_area_struct *vma;
         unsigned long addr;
-        int ret = 0;
+        int i, ret = 0;
 
         addr = gfn_to_hva(kvm, gfn);
         if (kvm_is_error_hva(addr))
-                return ret;
+                return page_size;
 
         down_read(&current->mm->mmap_sem);
         vma = find_vma(current->mm, addr);
-        if (vma && is_vm_hugetlb_page(vma))
-                ret = 1;
+        if (!vma)
+                goto out;
+
+        page_size = vma_kernel_pagesize(vma);
+
+out:
         up_read(&current->mm->mmap_sem);
 
+        for (i = PT_PAGE_TABLE_LEVEL;
+             i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) {
+                if (page_size >= KVM_HPAGE_SIZE(i))
+                        ret = i;
+                else
+                        break;
+        }
+
         return ret;
 }
 
-static int is_largepage_backed(struct kvm_vcpu *vcpu, gfn_t large_gfn)
+static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
 {
         struct kvm_memory_slot *slot;
-
-        if (has_wrprotected_page(vcpu->kvm, large_gfn))
-                return 0;
-
-        if (!host_largepage_backed(vcpu->kvm, large_gfn))
-                return 0;
+        int host_level;
+        int level = PT_PAGE_TABLE_LEVEL;
 
         slot = gfn_to_memslot(vcpu->kvm, large_gfn);
         if (slot && slot->dirty_bitmap)
-                return 0;
+                return PT_PAGE_TABLE_LEVEL;
 
-        return 1;
+        host_level = host_mapping_level(vcpu->kvm, large_gfn);
+
+        if (host_level == PT_PAGE_TABLE_LEVEL)
+                return host_level;
+
+        for (level = PT_DIRECTORY_LEVEL; level <= host_level; ++level) {
+
+                if (has_wrprotected_page(vcpu->kvm, large_gfn, level))
+                        break;
+        }
+
+        return level - 1;
 }
 
 /*
@@ -1733,7 +1768,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
         if ((pte_access & ACC_WRITE_MASK)
             || (write_fault && !is_write_protection(vcpu) && !user_fault)) {
 
-                if (largepage && has_wrprotected_page(vcpu->kvm, gfn)) {
+                if (largepage && has_wrprotected_page(vcpu->kvm, gfn, 1)) {
                         ret = 1;
                         spte = shadow_trap_nonpresent_pte;
                         goto set_pte;
@@ -1884,8 +1919,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
         pfn_t pfn;
         unsigned long mmu_seq;
 
-        if (is_largepage_backed(vcpu, gfn &
-                        ~(KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL) - 1))) {
+        if (mapping_level(vcpu, gfn) == PT_DIRECTORY_LEVEL) {
                 gfn &= ~(KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL) - 1);
                 largepage = 1;
         }
@@ -2091,8 +2125,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
         if (r)
                 return r;
 
-        if (is_largepage_backed(vcpu, gfn &
-                        ~(KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL) - 1))) {
+        if (mapping_level(vcpu, gfn) == PT_DIRECTORY_LEVEL) {
                 gfn &= ~(KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL) - 1);
                 largepage = 1;
         }
@@ -2494,7 +2527,8 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                 return;
         gfn = (gpte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
 
-        if (is_large_pte(gpte) && is_largepage_backed(vcpu, gfn)) {
+        if (is_large_pte(gpte) &&
+            (mapping_level(vcpu, gfn) == PT_DIRECTORY_LEVEL)) {
                 gfn &= ~(KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL) - 1);
                 vcpu->arch.update_pte.largepage = 1;
         }