KVM: nVMX: vmread/vmwrite: Use shadow vmcs12 if running L2

This is done as a preparation to VMCS shadowing emulation.

Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c7d08a5..f91a159 100644 (file)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -8341,6 +8341,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
        unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
        u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO);
        gva_t gva = 0;
+       struct vmcs12 *vmcs12;
 
        if (!nested_vmx_check_permission(vcpu))
                return 1;
@@ -8348,10 +8349,24 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
        if (!nested_vmx_check_vmcs12(vcpu))
                return kvm_skip_emulated_instruction(vcpu);
 
+       if (!is_guest_mode(vcpu))
+               vmcs12 = get_vmcs12(vcpu);
+       else {
+               /*
+                * When vmcs->vmcs_link_pointer is -1ull, any VMREAD
+                * to shadowed-field sets the ALU flags for VMfailInvalid.
+                */
+               if (get_vmcs12(vcpu)->vmcs_link_pointer == -1ull) {
+                       nested_vmx_failInvalid(vcpu);
+                       return kvm_skip_emulated_instruction(vcpu);
+               }
+               vmcs12 = get_shadow_vmcs12(vcpu);
+       }
+
        /* Decode instruction info and find the field to read */
        field = kvm_register_readl(vcpu, (((vmx_instruction_info) >> 28) & 0xf));
        /* Read the field, zero-extended to a u64 field_value */
-       if (vmcs12_read_any(get_vmcs12(vcpu), field, &field_value) < 0) {
+       if (vmcs12_read_any(vmcs12, field, &field_value) < 0) {
                nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
                return kvm_skip_emulated_instruction(vcpu);
        }
@@ -8393,6 +8408,7 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
         */
        u64 field_value = 0;
        struct x86_exception e;
+       struct vmcs12 *vmcs12;
 
        if (!nested_vmx_check_permission(vcpu))
                return 1;
@@ -8427,23 +8443,44 @@ static int handle_vmwrite(struct kvm_vcpu *vcpu)
                return kvm_skip_emulated_instruction(vcpu);
        }
 
-       if (vmcs12_write_any(get_vmcs12(vcpu), field, field_value) < 0) {
+       if (!is_guest_mode(vcpu))
+               vmcs12 = get_vmcs12(vcpu);
+       else {
+               /*
+                * When vmcs->vmcs_link_pointer is -1ull, any VMWRITE
+                * to shadowed-field sets the ALU flags for VMfailInvalid.
+                */
+               if (get_vmcs12(vcpu)->vmcs_link_pointer == -1ull) {
+                       nested_vmx_failInvalid(vcpu);
+                       return kvm_skip_emulated_instruction(vcpu);
+               }
+               vmcs12 = get_shadow_vmcs12(vcpu);
+
+       }
+
+       if (vmcs12_write_any(vmcs12, field, field_value) < 0) {
                nested_vmx_failValid(vcpu, VMXERR_UNSUPPORTED_VMCS_COMPONENT);
                return kvm_skip_emulated_instruction(vcpu);
        }
 
-       switch (field) {
+       /*
+        * Do not track vmcs12 dirty-state if in guest-mode
+        * as we actually dirty shadow vmcs12 instead of vmcs12.
+        */
+       if (!is_guest_mode(vcpu)) {
+               switch (field) {
 #define SHADOW_FIELD_RW(x) case x:
 #include "vmx_shadow_fields.h"
-               /*
-                * The fields that can be updated by L1 without a vmexit are
-                * always updated in the vmcs02, the others go down the slow
-                * path of prepare_vmcs02.
-                */
-               break;
-       default:
-               vmx->nested.dirty_vmcs12 = true;
-               break;
+                       /*
+                        * The fields that can be updated by L1 without a vmexit are
+                        * always updated in the vmcs02, the others go down the slow
+                        * path of prepare_vmcs02.
+                        */
+                       break;
+               default:
+                       vmx->nested.dirty_vmcs12 = true;
+                       break;
+               }
        }
 
        nested_vmx_succeed(vcpu);