From: Jim Mattson jmattson@google.com
commit dd2d6042b7f4a5440705b4ffc6c4c2dba81a43b7 upstream.
According to the SDM, a VMWRITE in VMX non-root operation with an invalid VMCS-link pointer results in VMfailInvalid before the validity of the VMCS field in the secondary source operand is checked.
For consistency, modify both handle_vmwrite and handle_vmread, even though there was no problem with the latter.
Fixes: 6d894f498f5d1 ("KVM: nVMX: vmread/vmwrite: Use shadow vmcs12 if running L2") Signed-off-by: Jim Mattson jmattson@google.com Cc: Liran Alon liran.alon@oracle.com Cc: Paolo Bonzini pbonzini@redhat.com Cc: Vitaly Kuznetsov vkuznets@redhat.com Reviewed-by: Peter Shier pshier@google.com Reviewed-by: Oliver Upton oupton@google.com Reviewed-by: Jon Cargille jcargill@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kvm/vmx/nested.c | 59 +++++++++++++++++++--------------------------- 1 file changed, 25 insertions(+), 34 deletions(-)
--- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -4609,32 +4609,28 @@ static int handle_vmread(struct kvm_vcpu { unsigned long field; u64 field_value; + struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION); u32 vmx_instruction_info = vmcs_read32(VMX_INSTRUCTION_INFO); int len; gva_t gva = 0; - struct vmcs12 *vmcs12; + struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu) + : get_vmcs12(vcpu); struct x86_exception e; short offset;
if (!nested_vmx_check_permission(vcpu)) return 1;
- if (to_vmx(vcpu)->nested.current_vmptr == -1ull) + /* + * In VMX non-root operation, when the VMCS-link pointer is -1ull, + * any VMREAD sets the ALU flags for VMfailInvalid. + */ + if (vmx->nested.current_vmptr == -1ull || + (is_guest_mode(vcpu) && + get_vmcs12(vcpu)->vmcs_link_pointer == -1ull)) return nested_vmx_failInvalid(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) - return nested_vmx_failInvalid(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));
@@ -4713,13 +4709,20 @@ static int handle_vmwrite(struct kvm_vcp */ u64 field_value = 0; struct x86_exception e; - struct vmcs12 *vmcs12; + struct vmcs12 *vmcs12 = is_guest_mode(vcpu) ? get_shadow_vmcs12(vcpu) + : get_vmcs12(vcpu); short offset;
if (!nested_vmx_check_permission(vcpu)) return 1;
- if (vmx->nested.current_vmptr == -1ull) + /* + * In VMX non-root operation, when the VMCS-link pointer is -1ull, + * any VMWRITE sets the ALU flags for VMfailInvalid. + */ + if (vmx->nested.current_vmptr == -1ull || + (is_guest_mode(vcpu) && + get_vmcs12(vcpu)->vmcs_link_pointer == -1ull)) return nested_vmx_failInvalid(vcpu);
if (vmx_instruction_info & (1u << 10)) @@ -4747,24 +4750,12 @@ static int handle_vmwrite(struct kvm_vcp return nested_vmx_failValid(vcpu, VMXERR_VMWRITE_READ_ONLY_VMCS_COMPONENT);
- if (!is_guest_mode(vcpu)) { - vmcs12 = get_vmcs12(vcpu); - - /* - * Ensure vmcs12 is up-to-date before any VMWRITE that dirties - * vmcs12, else we may crush a field or consume a stale value. - */ - if (!is_shadow_field_rw(field)) - copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12); - } 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) - return nested_vmx_failInvalid(vcpu); - vmcs12 = get_shadow_vmcs12(vcpu); - } + /* + * Ensure vmcs12 is up-to-date before any VMWRITE that dirties + * vmcs12, else we may crush a field or consume a stale value. + */ + if (!is_guest_mode(vcpu) && !is_shadow_field_rw(field)) + copy_vmcs02_to_vmcs12_rare(vcpu, vmcs12);
offset = vmcs_field_to_offset(field); if (offset < 0)