KVM: MMU: Add infrastructure for two-level page walker

This patch introduces a mmu-callback to translate gpa
addresses in the walk_addr code. This is later used to
translate l2_gpa addresses into l1_gpa addresses.

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

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 3fde5b3..4915b7c 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -243,6 +243,7 @@ struct kvm_mmu {
        void (*free)(struct kvm_vcpu *vcpu);
        gpa_t (*gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t gva, u32 access,
                            u32 *error);
+       gpa_t (*translate_gpa)(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access);
        void (*prefetch_page)(struct kvm_vcpu *vcpu,
                              struct kvm_mmu_page *page);
        int (*sync_page)(struct kvm_vcpu *vcpu,

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 48b74d2..2364c2c 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3448,6 +3448,11 @@ void kvm_get_segment(struct kvm_vcpu *vcpu,
        kvm_x86_ops->get_segment(vcpu, var, seg);
 }
 
+static gpa_t translate_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access)
+{
+       return gpa;
+}
+
 gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva, u32 *error)
 {
        u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
@@ -5659,6 +5664,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 
        vcpu->arch.emulate_ctxt.ops = &emulate_ops;
        vcpu->arch.mmu.root_hpa = INVALID_PAGE;
+       vcpu->arch.mmu.translate_gpa = translate_gpa;
        if (!irqchip_in_kernel(kvm) || kvm_vcpu_is_bsp(vcpu))
                vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
        else

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index f2ecdd5..917e68f 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -534,6 +534,11 @@ static inline gpa_t gfn_to_gpa(gfn_t gfn)
        return (gpa_t)gfn << PAGE_SHIFT;
 }
 
+static inline gfn_t gpa_to_gfn(gpa_t gpa)
+{
+       return (gfn_t)(gpa >> PAGE_SHIFT);
+}
+
 static inline hpa_t pfn_to_hpa(pfn_t pfn)
 {
        return (hpa_t)pfn << PAGE_SHIFT;