| From c4914b12ffe2715c5af0ef4ba1024988b9d65e6f Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Tue, 14 Apr 2020 22:47:45 +0000 |
| Subject: kvm: nVMX: reflect MTF VM-exits if injected by L1 |
| |
| From: Oliver Upton <oupton@google.com> |
| |
| [ Upstream commit b045ae906b42afb361dc7ecf1a3cea110fb0a65f ] |
| |
| According to SDM 26.6.2, it is possible to inject an MTF VM-exit via the |
| VM-entry interruption-information field regardless of the 'monitor trap |
| flag' VM-execution control. KVM appropriately copies the VM-entry |
| interruption-information field from vmcs12 to vmcs02. However, if L1 |
| has not set the 'monitor trap flag' VM-execution control, KVM fails to |
| reflect the subsequent MTF VM-exit into L1. |
| |
| Fix this by consulting the VM-entry interruption-information field of |
| vmcs12 to determine if L1 has injected the MTF VM-exit. If so, reflect |
| the exit, regardless of the 'monitor trap flag' VM-execution control. |
| |
| Fixes: 5f3d45e7f282 ("kvm/x86: add support for MONITOR_TRAP_FLAG") |
| Signed-off-by: Oliver Upton <oupton@google.com> |
| Reviewed-by: Peter Shier <pshier@google.com> |
| Reviewed-by: Jim Mattson <jmattson@google.com> |
| Message-Id: <20200414224746.240324-1-oupton@google.com> |
| Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| arch/x86/kvm/vmx/nested.c | 19 ++++++++++++++++++- |
| 1 file changed, 18 insertions(+), 1 deletion(-) |
| |
| diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c |
| index b773989308015..3a2f05ef51fa4 100644 |
| --- a/arch/x86/kvm/vmx/nested.c |
| +++ b/arch/x86/kvm/vmx/nested.c |
| @@ -5504,6 +5504,23 @@ static bool nested_vmx_exit_handled_vmcs_access(struct kvm_vcpu *vcpu, |
| return 1 & (b >> (field & 7)); |
| } |
| |
| +static bool nested_vmx_exit_handled_mtf(struct vmcs12 *vmcs12) |
| +{ |
| + u32 entry_intr_info = vmcs12->vm_entry_intr_info_field; |
| + |
| + if (nested_cpu_has_mtf(vmcs12)) |
| + return true; |
| + |
| + /* |
| + * An MTF VM-exit may be injected into the guest by setting the |
| + * interruption-type to 7 (other event) and the vector field to 0. Such |
| + * is the case regardless of the 'monitor trap flag' VM-execution |
| + * control. |
| + */ |
| + return entry_intr_info == (INTR_INFO_VALID_MASK |
| + | INTR_TYPE_OTHER_EVENT); |
| +} |
| + |
| /* |
| * Return 1 if we should exit from L2 to L1 to handle an exit, or 0 if we |
| * should handle it ourselves in L0 (and then continue L2). Only call this |
| @@ -5618,7 +5635,7 @@ bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason) |
| case EXIT_REASON_MWAIT_INSTRUCTION: |
| return nested_cpu_has(vmcs12, CPU_BASED_MWAIT_EXITING); |
| case EXIT_REASON_MONITOR_TRAP_FLAG: |
| - return nested_cpu_has_mtf(vmcs12); |
| + return nested_vmx_exit_handled_mtf(vmcs12); |
| case EXIT_REASON_MONITOR_INSTRUCTION: |
| return nested_cpu_has(vmcs12, CPU_BASED_MONITOR_EXITING); |
| case EXIT_REASON_PAUSE_INSTRUCTION: |
| -- |
| 2.20.1 |
| |