diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2018-03-12 10:56:13 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-03-16 22:01:38 +0100 |
| commit | 2bb8cafea80bf69c0e729bf1ad1bcd1d6c53248d (patch) | |
| tree | 38958959d708fa92778368a7e269fe9b474e465f /arch/x86/kvm/vmx.c | |
| parent | e1de91ccab311ec8007c6e77b0dbb4e3421fd298 (diff) | |
| download | linux-0-day-2bb8cafea80bf69c0e729bf1ad1bcd1d6c53248d.tar.gz linux-0-day-2bb8cafea80bf69c0e729bf1ad1bcd1d6c53248d.tar.xz | |
KVM: vVMX: signal failure for nested VMEntry if emulation_required
Fail a nested VMEntry with EXIT_REASON_INVALID_STATE if L2 guest state
is invalid, i.e. vmcs12 contained invalid guest state, and unrestricted
guest is disabled in L0 (and by extension disabled in L1).
WARN_ON_ONCE in handle_invalid_guest_state() if we're attempting to
emulate L2, i.e. nested_run_pending is true, to aid debug in the
(hopefully unlikely) scenario that we somehow skip the nested VMEntry
consistency check, e.g. due to a L0 bug.
Note: KVM relies on hardware to detect the scenario where unrestricted
guest is enabled in L0 but disabled in L1 and vmcs12 contains invalid
guest state, i.e. checking emulation_required in prepare_vmcs02 is
required only to handle the case were unrestricted guest is disabled
in L0 since L0 never actually attempts VMLAUNCH/VMRESUME with vmcs02.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 6cefd7b3ff7fc..5d67a15b51160 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6865,6 +6865,13 @@ static int handle_invalid_guest_state(struct kvm_vcpu *vcpu) bool intr_window_requested; unsigned count = 130; + /* + * We should never reach the point where we are emulating L2 + * due to invalid guest state as that means we incorrectly + * allowed a nested VMEntry with an invalid vmcs12. + */ + WARN_ON_ONCE(vmx->emulation_required && vmx->nested.nested_run_pending); + cpu_exec_ctrl = vmcs_read32(CPU_BASED_VM_EXEC_CONTROL); intr_window_requested = cpu_exec_ctrl & CPU_BASED_VIRTUAL_INTR_PENDING; @@ -10990,6 +10997,14 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, vmx->nested.dirty_vmcs12 = false; } + /* + * Guest state is invalid and unrestricted guest is disabled, + * which means L1 attempted VMEntry to L2 with invalid state. + * Fail the VMEntry. + */ + if (vmx->emulation_required) + return 1; + /* Shadow page tables on either EPT or shadow page tables. */ if (nested_vmx_load_cr3(vcpu, vmcs12->guest_cr3, nested_cpu_has_ept(vmcs12), entry_failure_code)) |