KVM: MMU: add TDP support to the KVM MMU

This patch contains the changes to the KVM MMU necessary for support of the
Nested Paging feature in AMD Barcelona and Phenom Processors.

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

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 33cd7c982dd3885b810a2fd9a5a918401538c30c..f7541fe22cd8ac02cce96df61579659239c3adcc 100644 (file)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1097,6 +1097,7 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
        int i;
        gfn_t root_gfn;
        struct kvm_mmu_page *sp;
+       int metaphysical = 0;
 
        root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
 
@@ -1105,14 +1106,20 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
                hpa_t root = vcpu->arch.mmu.root_hpa;
 
                ASSERT(!VALID_PAGE(root));
+               if (tdp_enabled)
+                       metaphysical = 1;
                sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
-                                     PT64_ROOT_LEVEL, 0, ACC_ALL, NULL);
+                                     PT64_ROOT_LEVEL, metaphysical,
+                                     ACC_ALL, NULL);
                root = __pa(sp->spt);
                ++sp->root_count;
                vcpu->arch.mmu.root_hpa = root;
                return;
        }
 #endif
+       metaphysical = !is_paging(vcpu);
+       if (tdp_enabled)
+               metaphysical = 1;
        for (i = 0; i < 4; ++i) {
                hpa_t root = vcpu->arch.mmu.pae_root[i];
 
@@ -1126,7 +1133,7 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
                } else if (vcpu->arch.mmu.root_level == 0)
                        root_gfn = 0;
                sp = kvm_mmu_get_page(vcpu, root_gfn, i << 30,
-                                     PT32_ROOT_LEVEL, !is_paging(vcpu),
+                                     PT32_ROOT_LEVEL, metaphysical,
                                      ACC_ALL, NULL);
                root = __pa(sp->spt);
                ++sp->root_count;
@@ -1160,6 +1167,36 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
                             error_code & PFERR_WRITE_MASK, gfn);
 }
 
+static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
+                               u32 error_code)
+{
+       struct page *page;
+       int r;
+
+       ASSERT(vcpu);
+       ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
+
+       r = mmu_topup_memory_caches(vcpu);
+       if (r)
+               return r;
+
+       down_read(&current->mm->mmap_sem);
+       page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
+       if (is_error_page(page)) {
+               kvm_release_page_clean(page);
+               up_read(&current->mm->mmap_sem);
+               return 1;
+       }
+       spin_lock(&vcpu->kvm->mmu_lock);
+       kvm_mmu_free_some_pages(vcpu);
+       r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
+                        gpa >> PAGE_SHIFT, page, TDP_ROOT_LEVEL);
+       spin_unlock(&vcpu->kvm->mmu_lock);
+       up_read(&current->mm->mmap_sem);
+
+       return r;
+}
+
 static void nonpaging_free(struct kvm_vcpu *vcpu)
 {
        mmu_free_roots(vcpu);
@@ -1253,7 +1290,35 @@ static int paging32E_init_context(struct kvm_vcpu *vcpu)
        return paging64_init_context_common(vcpu, PT32E_ROOT_LEVEL);
 }
 
-static int init_kvm_mmu(struct kvm_vcpu *vcpu)
+static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
+{
+       struct kvm_mmu *context = &vcpu->arch.mmu;
+
+       context->new_cr3 = nonpaging_new_cr3;
+       context->page_fault = tdp_page_fault;
+       context->free = nonpaging_free;
+       context->prefetch_page = nonpaging_prefetch_page;
+       context->shadow_root_level = TDP_ROOT_LEVEL;
+       context->root_hpa = INVALID_PAGE;
+
+       if (!is_paging(vcpu)) {
+               context->gva_to_gpa = nonpaging_gva_to_gpa;
+               context->root_level = 0;
+       } else if (is_long_mode(vcpu)) {
+               context->gva_to_gpa = paging64_gva_to_gpa;
+               context->root_level = PT64_ROOT_LEVEL;
+       } else if (is_pae(vcpu)) {
+               context->gva_to_gpa = paging64_gva_to_gpa;
+               context->root_level = PT32E_ROOT_LEVEL;
+       } else {
+               context->gva_to_gpa = paging32_gva_to_gpa;
+               context->root_level = PT32_ROOT_LEVEL;
+       }
+
+       return 0;
+}
+
+static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
 {
        ASSERT(vcpu);
        ASSERT(!VALID_PAGE(vcpu->arch.mmu.root_hpa));
@@ -1268,6 +1333,14 @@ static int init_kvm_mmu(struct kvm_vcpu *vcpu)
                return paging32_init_context(vcpu);
 }
 
+static int init_kvm_mmu(struct kvm_vcpu *vcpu)
+{
+       if (tdp_enabled)
+               return init_kvm_tdp_mmu(vcpu);
+       else
+               return init_kvm_softmmu(vcpu);
+}
+
 static void destroy_kvm_mmu(struct kvm_vcpu *vcpu)
 {
        ASSERT(vcpu);

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 1fce19ec7a2380c61c79ef0f50e71e4c39d2af66..e64e9f56a65eb04889cb2c5912c9fda9d36d96f1 100644 (file)
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -3,6 +3,12 @@
 
 #include <linux/kvm_host.h>
 
+#ifdef CONFIG_X86_64
+#define TDP_ROOT_LEVEL PT64_ROOT_LEVEL
+#else
+#define TDP_ROOT_LEVEL PT32E_ROOT_LEVEL
+#endif
+
 static inline void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
 {
        if (unlikely(vcpu->kvm->arch.n_free_mmu_pages < KVM_MIN_FREE_MMU_PAGES))