[kvm-devel] [PATCH 7/8] MMU: add HAP support to the KVM MMU

[Joerg Roedel]

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 <[EMAIL PROTECTED]>
---
 arch/x86/kvm/mmu.c |   74 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 arch/x86/kvm/mmu.h |    6 ++++
 2 files changed, 78 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index dfbcf5e..bce27ca 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1072,6 +1072,7 @@ 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;
 
@@ -1080,8 +1081,11 @@ static void mmu_alloc_roots(struct kvm_vcpu *vcpu)
                hpa_t root = vcpu->arch.mmu.root_hpa;
 
                ASSERT(!VALID_PAGE(root));
+               if (kvm_x86_ops->hap_enabled())
+                       metaphysical = 1;
                sp = kvm_mmu_get_page(vcpu, root_gfn, 0,
-                                     PT64_ROOT_LEVEL, 0, ACC_ALL, NULL, NULL);
+                                     PT64_ROOT_LEVEL, metaphysical,
+                                     ACC_ALL, NULL, NULL);
                root = __pa(sp->spt);
                ++sp->root_count;
                vcpu->arch.mmu.root_hpa = root;
@@ -1135,6 +1139,36 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, 
gva_t gva,
                             error_code & PFERR_WRITE_MASK, gfn);
 }
 
+static int hap_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, HAP_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);
@@ -1228,7 +1262,35 @@ 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_hap_mmu(struct kvm_vcpu *vcpu)
+{
+       struct kvm_mmu *context = &vcpu->arch.mmu;
+
+       context->new_cr3 = nonpaging_new_cr3;
+       context->page_fault = hap_page_fault;
+       context->free = nonpaging_free;
+       context->prefetch_page = nonpaging_prefetch_page;
+       context->shadow_root_level = HAP_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));
@@ -1243,6 +1305,14 @@ static int init_kvm_mmu(struct kvm_vcpu *vcpu)
                return paging32_init_context(vcpu);
 }
 
+static int init_kvm_mmu(struct kvm_vcpu *vcpu)
+{
+       if (kvm_x86_ops->hap_enabled())
+               return init_kvm_hap_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 1fce19e..ef880a5 100644
--- 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 HAP_ROOT_LEVEL PT64_ROOT_LEVEL
+#else
+#define HAP_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))
-- 
1.5.3.7




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