KVM: MMU: Introduce get_cr3 function pointer

This function pointer in the MMU context is required to
implement Nested Nested Paging.

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

3 files changed, 11 insertions, 3 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 81a51473f745..6c97b8debfa8 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -237,6 +237,7 @@ struct kvm_pio_request {
 struct kvm_mmu {
         void (*new_cr3)(struct kvm_vcpu *vcpu);
         void (*set_cr3)(struct kvm_vcpu *vcpu, unsigned long root);
+        unsigned long (*get_cr3)(struct kvm_vcpu *vcpu);
         int (*page_fault)(struct kvm_vcpu *vcpu, gva_t gva, u32 err);
         void (*free)(struct kvm_vcpu *vcpu);
         gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva, u32 access,
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a55f8d5a7985..e4a7de4c8c77 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2365,7 +2365,7 @@ static int mmu_alloc_roots(struct kvm_vcpu *vcpu)
         int direct = 0;
         u64 pdptr;
 
-        root_gfn = vcpu->arch.cr3 >> PAGE_SHIFT;
+        root_gfn = vcpu->arch.mmu.get_cr3(vcpu) >> PAGE_SHIFT;
 
         if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
                 hpa_t root = vcpu->arch.mmu.root_hpa;
@@ -2562,6 +2562,11 @@ static void paging_new_cr3(struct kvm_vcpu *vcpu)
         mmu_free_roots(vcpu);
 }
 
+static unsigned long get_cr3(struct kvm_vcpu *vcpu)
+{
+        return vcpu->arch.cr3;
+}
+
 static void inject_page_fault(struct kvm_vcpu *vcpu,
                               u64 addr,
                               u32 err_code)
@@ -2715,6 +2720,7 @@ static int init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
         context->root_hpa = INVALID_PAGE;
         context->direct_map = true;
         context->set_cr3 = kvm_x86_ops->set_tdp_cr3;
+        context->get_cr3 = get_cr3;
 
         if (!is_paging(vcpu)) {
                 context->gva_to_gpa = nonpaging_gva_to_gpa;
@@ -2755,6 +2761,7 @@ static int init_kvm_softmmu(struct kvm_vcpu *vcpu)
         vcpu->arch.mmu.base_role.cr4_pae = !!is_pae(vcpu);
         vcpu->arch.mmu.base_role.cr0_wp  = is_write_protection(vcpu);
         vcpu->arch.mmu.set_cr3           = kvm_x86_ops->set_cr3;
+        vcpu->arch.mmu.get_cr3           = get_cr3;
 
         return r;
 }
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index e4ad3dc84df3..13d0c06b1bc8 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -130,7 +130,7 @@ walk:
         present = true;
         eperm = rsvd_fault = false;
         walker->level = vcpu->arch.mmu.root_level;
-        pte = vcpu->arch.cr3;
+        pte = vcpu->arch.mmu.get_cr3(vcpu);
 #if PTTYPE == 64
         if (vcpu->arch.mmu.root_level == PT32E_ROOT_LEVEL) {
                 pte = kvm_pdptr_read(vcpu, (addr >> 30) & 3);
@@ -143,7 +143,7 @@ walk:
         }
 #endif
         ASSERT((!is_long_mode(vcpu) && is_pae(vcpu)) ||
-               (vcpu->arch.cr3 & CR3_NONPAE_RESERVED_BITS) == 0);
+               (vcpu->arch.mmu.get_cr3(vcpu) & CR3_NONPAE_RESERVED_BITS) == 0);
 
         pt_access = ACC_ALL;