lkml.org 
[lkml]   [2019]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v8 3/3] KVM: vmx: Introduce handle_unexpected_vmexit and handle WAITPKG vmexit
Date
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. Introduce a common
exit helper handle_unexpected_vmexit() to handle these unexpected VM-exit.

Suggested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Jingqi Liu <jingqi.liu@intel.com>
Signed-off-by: Jingqi Liu <jingqi.liu@intel.com>
Signed-off-by: Tao Xu <tao3.xu@intel.com>
---

Changes in v8:
- Introduce a common exit helper handle_unexpected_vmexit (Sean)
---
arch/x86/include/uapi/asm/vmx.h | 6 +++++-
arch/x86/kvm/vmx/nested.c | 4 ++++
arch/x86/kvm/vmx/vmx.c | 28 ++++++++++++----------------
3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/uapi/asm/vmx.h b/arch/x86/include/uapi/asm/vmx.h
index d213ec5c3766..d88d7a68849b 100644
--- a/arch/x86/include/uapi/asm/vmx.h
+++ b/arch/x86/include/uapi/asm/vmx.h
@@ -85,6 +85,8 @@
#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" }, \
@@ -142,7 +144,9 @@
{ 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 a4d5da34b306..12a162a2d798 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5213,6 +5213,10 @@ 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 0224b087aad3..db5bdc468f70 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4967,20 +4967,6 @@ 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)) {
@@ -5499,6 +5485,14 @@ static int handle_encls(struct kvm_vcpu *vcpu)
return 1;
}

+static int handle_unexpected_vmexit(struct kvm_vcpu *vcpu)
+{
+ kvm_skip_emulated_instruction(vcpu);
+ WARN_ONCE(1, "Unexpected VM-Exit Reason = 0x%x",
+ vmcs_read32(VM_EXIT_REASON));
+ return 1;
+}
+
/*
* 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
@@ -5550,13 +5544,15 @@ 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 =
--
2.20.1
\
 
 \ /
  Last update: 2019-07-16 08:59    [W:0.074 / U:3.028 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site