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authorFelix Wilhelm <fwilhelm@google.com>2018-06-11 09:43:44 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2018-06-12 15:06:06 +0200
commit727ba748e110b4de50d142edca9d6a9b7e6111d8 (patch)
treeb7573effd1110a11aac720cc38407bfdb45f651f /arch/x86
parentf4160e459c57646122beaea3f163b798179ea446 (diff)
downloadlinux-727ba748e110b4de50d142edca9d6a9b7e6111d8.tar.gz
kvm: nVMX: Enforce cpl=0 for VMX instructions
VMX instructions executed inside a L1 VM will always trigger a VM exit even when executed with cpl 3. This means we must perform the privilege check in software. Fixes: 70f3aac964ae("kvm: nVMX: Remove superfluous VMX instruction fault checks") Cc: stable@vger.kernel.org Signed-off-by: Felix Wilhelm <fwilhelm@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/vmx.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 709de996f063..4bf1f9de9332 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7905,6 +7905,12 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
return 1;
}
+ /* CPL=0 must be checked manually. */
+ if (vmx_get_cpl(vcpu)) {
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 1;
+ }
+
if (vmx->nested.vmxon) {
nested_vmx_failValid(vcpu, VMXERR_VMXON_IN_VMX_ROOT_OPERATION);
return kvm_skip_emulated_instruction(vcpu);
@@ -7964,6 +7970,11 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
*/
static int nested_vmx_check_permission(struct kvm_vcpu *vcpu)
{
+ if (vmx_get_cpl(vcpu)) {
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ return 0;
+ }
+
if (!to_vmx(vcpu)->nested.vmxon) {
kvm_queue_exception(vcpu, UD_VECTOR);
return 0;
@@ -8283,7 +8294,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
if (get_vmx_mem_address(vcpu, exit_qualification,
vmx_instruction_info, true, &gva))
return 1;
- /* _system ok, as hardware has verified cpl=0 */
+ /* _system ok, nested_vmx_check_permission has verified cpl=0 */
kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, gva,
&field_value, (is_long_mode(vcpu) ? 8 : 4), NULL);
}
@@ -8448,7 +8459,7 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu)
if (get_vmx_mem_address(vcpu, exit_qualification,
vmx_instruction_info, true, &vmcs_gva))
return 1;
- /* ok to use *_system, as hardware has verified cpl=0 */
+ /* *_system ok, nested_vmx_check_permission has verified cpl=0 */
if (kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, vmcs_gva,
(void *)&to_vmx(vcpu)->nested.current_vmptr,
sizeof(u64), &e)) {