[RESEND v13 01/10] KVM: x86: Move common set/get handler of MSR_IA32_DEBUGCTLMSR to VMX

Like Xu
2021-01-08T01:44:54Z

SVM already has specific handlers of MSR_IA32_DEBUGCTLMSR in the
svm_get/set_msr, so the x86 common part can be safely moved to VMX.

Add vmx_supported_debugctl() to refactor the throwing logic of #GP.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/kvm/vmx/capabilities.h | 5 +++++
arch/x86/kvm/vmx/vmx.c | 19 ++++++++++++++++---
arch/x86/kvm/x86.c | 13 -------------
3 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 3a1861403d73..a58cf3655351 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -378,4 +378,9 @@ static inline u64 vmx_get_perf_capabilities(void)
return PMU_CAP_FW_WRITES;
}

+static inline u64 vmx_supported_debugctl(void)
+{
+ return DEBUGCTLMSR_LBR | DEBUGCTLMSR_BTF;
+}
+
#endif /* __KVM_X86_VMX_CAPS_H */
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 2af05d3b0590..23b46327527e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1924,6 +1924,9 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
!guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
return 1;
goto find_uret_msr;
+ case MSR_IA32_DEBUGCTLMSR:
+ msr_info->data = 0;
+ break;
default:
find_uret_msr:
msr = vmx_find_uret_msr(vmx, msr_info->index);
@@ -2002,9 +2005,19 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
VM_EXIT_SAVE_DEBUG_CONTROLS)
get_vmcs12(vcpu)->guest_ia32_debugctl = data;

- ret = kvm_set_msr_common(vcpu, msr_info);
- break;
-
+ if (!data) {
+ /* We support the non-activated case already */
+ return 0;
+ } else if (data & ~vmx_supported_debugctl()) {
+ /*
+ * Values other than LBR and BTF are vendor-specific,
+ * thus reserved and should throw a #GP.
+ */
+ return 1;
+ }
+ vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
+ __func__, data);
+ return 0;
case MSR_IA32_BNDCFGS:
if (!kvm_mpx_supported() ||
(!msr_info->host_initiated &&
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0287840b93e0..c765fd72a66c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3063,18 +3063,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 1;
}
break;
- case MSR_IA32_DEBUGCTLMSR:
- if (!data) {
- /* We support the non-activated case already */
- break;
- } else if (data & ~(DEBUGCTLMSR_LBR | DEBUGCTLMSR_BTF)) {
- /* Values other than LBR and BTF are vendor-specific,
- thus reserved and should throw a #GP */
- return 1;
- } else if (report_ignored_msrs)
- vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
- __func__, data);
- break;
case 0x200 ... 0x2ff:
return kvm_mtrr_set_msr(vcpu, msr, data);
case MSR_IA32_APICBASE:
@@ -3347,7 +3335,6 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
switch (msr_info->index) {
case MSR_IA32_PLATFORM_ID:
case MSR_IA32_EBL_CR_POWERON:
- case MSR_IA32_DEBUGCTLMSR:
case MSR_IA32_LASTBRANCHFROMIP:
case MSR_IA32_LASTBRANCHTOIP:
case MSR_IA32_LASTINTFROMIP:
--
2.29.2