As the latest Intel 64 and IA-32 Architectures Software Developer's
Manual, UMWAIT and TPAUSE instructions cause a VM exit if the
RDTSC exiting and enable user wait and pause VM-execution
controls are both 1.
Because KVM never enable RDTSC exiting, the vm-exit for UMWAIT and
TPAUSE should never happen. Considering EXIT_REASON_XSAVES and
EXIT_REASON_XRSTORS is also unexpected VM-exit for KVM. Reuse the code
of 'commit 7396d337cfad ("KVM: x86: Return to userspace with internal
error on unexpected exit reason"), and introduce a common exit helper
handle_unexpected_vmexit() to handle these unexpected VM-exit.
Suggested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Co-developed-by: Jingqi Liu <jingqi.liu@xxxxxxxxx>
Signed-off-by: Jingqi Liu <jingqi.liu@xxxxxxxxx>
Signed-off-by: Tao Xu <tao3.xu@xxxxxxxxx>
---
arch/x86/include/uapi/asm/vmx.h | 6 +++-
arch/x86/kvm/vmx/nested.c | 4 +++
arch/x86/kvm/vmx/vmx.c | 51 ++++++++++++++++-----------------
3 files changed, 33 insertions(+), 28 deletions(-)
diff --git a/arch/x86/include/uapi/asm/vmx.h b/arch/x86/include/uapi/asm/vmx.h
index f01950aa7fae..3eb8411ab60e 100644
--- a/arch/x86/include/uapi/asm/vmx.h
+++ b/arch/x86/include/uapi/asm/vmx.h
@@ -86,6 +86,8 @@
#define EXIT_REASON_PML_FULL 62
#define EXIT_REASON_XSAVES 63
#define EXIT_REASON_XRSTORS 64
+#define EXIT_REASON_UMWAIT 67
+#define EXIT_REASON_TPAUSE 68
#define VMX_EXIT_REASONS \
{ EXIT_REASON_EXCEPTION_NMI, "EXCEPTION_NMI" }, \
@@ -144,7 +146,9 @@
{ EXIT_REASON_RDSEED, "RDSEED" }, \
{ EXIT_REASON_PML_FULL, "PML_FULL" }, \
{ EXIT_REASON_XSAVES, "XSAVES" }, \
- { EXIT_REASON_XRSTORS, "XRSTORS" }
+ { EXIT_REASON_XRSTORS, "XRSTORS" }, \
+ { EXIT_REASON_UMWAIT, "UMWAIT" }, \
+ { EXIT_REASON_TPAUSE, "TPAUSE" }
#define VMX_ABORT_SAVE_GUEST_MSR_FAIL 1
#define VMX_ABORT_LOAD_HOST_PDPTE_FAIL 2
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 4a57134a8aee..41abc62c9a8a 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5479,6 +5479,10 @@ bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason)
case EXIT_REASON_ENCLS:
/* SGX is never exposed to L1 */
return false;
+ case EXIT_REASON_UMWAIT:
+ case EXIT_REASON_TPAUSE:
+ return nested_cpu_has2(vmcs12,
+ SECONDARY_EXEC_ENABLE_USR_WAIT_PAUSE);
default:
return true;
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 3567478a0472..f1a5d32111af 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5045,20 +5045,6 @@ static int handle_xsetbv(struct kvm_vcpu *vcpu)
return 1;
}
-static int handle_xsaves(struct kvm_vcpu *vcpu)
-{
- kvm_skip_emulated_instruction(vcpu);
- WARN(1, "this should never happen\n");
- return 1;
-}
-
-static int handle_xrstors(struct kvm_vcpu *vcpu)
-{
- kvm_skip_emulated_instruction(vcpu);
- WARN(1, "this should never happen\n");
- return 1;
-}
-
static int handle_apic_access(struct kvm_vcpu *vcpu)
{
if (likely(fasteoi)) {
@@ -5552,6 +5538,24 @@ static int handle_encls(struct kvm_vcpu *vcpu)
return 1;
}
+static int handle_unexpected_vmexit(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ vcpu_unimpl(vcpu, "vmx: unexpected exit reason 0x%x\n",
+ vmx->exit_reason);
+ dump_vmcs();
+ vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+ vcpu->run->internal.suberror =
+ KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON;
+ vcpu->run->internal.ndata = 1;
+ vcpu->run->internal.data[0] = vmx->exit_reason;
+ kvm_skip_emulated_instruction(vcpu);
+ WARN_ONCE(1, "Unexpected VM-Exit Reason = 0x%x",
+ vmcs_read32(VM_EXIT_REASON));
+ return 0;
+}
+
/*
* The exit handlers return 1 if the exit was handled fully and guest execution
* may resume. Otherwise they set the kvm_run parameter to indicate what needs
@@ -5603,13 +5607,15 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
[EXIT_REASON_INVVPID] = handle_vmx_instruction,
[EXIT_REASON_RDRAND] = handle_invalid_op,
[EXIT_REASON_RDSEED] = handle_invalid_op,
- [EXIT_REASON_XSAVES] = handle_xsaves,
- [EXIT_REASON_XRSTORS] = handle_xrstors,
+ [EXIT_REASON_XSAVES] = handle_unexpected_vmexit,
+ [EXIT_REASON_XRSTORS] = handle_unexpected_vmexit,
[EXIT_REASON_PML_FULL] = handle_pml_full,
[EXIT_REASON_INVPCID] = handle_invpcid,
[EXIT_REASON_VMFUNC] = handle_vmx_instruction,
[EXIT_REASON_PREEMPTION_TIMER] = handle_preemption_timer,
[EXIT_REASON_ENCLS] = handle_encls,
+ [EXIT_REASON_UMWAIT] = handle_unexpected_vmexit,
+ [EXIT_REASON_TPAUSE] = handle_unexpected_vmexit,
};
static const int kvm_vmx_max_exit_handlers =
@@ -5946,17 +5952,8 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
if (exit_reason < kvm_vmx_max_exit_handlers
&& kvm_vmx_exit_handlers[exit_reason])
return kvm_vmx_exit_handlers[exit_reason](vcpu);
- else {
- vcpu_unimpl(vcpu, "vmx: unexpected exit reason 0x%x\n",
- exit_reason);
- dump_vmcs();
- vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- vcpu->run->internal.suberror =
- KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON;
- vcpu->run->internal.ndata = 1;
- vcpu->run->internal.data[0] = exit_reason;
- return 0;
- }
+ else
+ return handle_unexpected_vmexit(vcpu);
}
/*
--
2.20.1
