[PATCH 9/9] KVM: x86: Disable intercept for Intel processor trace MSRs

From: Luwei Kang
Date: Mon Oct 16 2017 - 21:57:41 EST


From: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>

Trap for Intel processor trace is none sense. Pass through to
guest directly.

Signed-off-by: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>
Signed-off-by: Luwei Kang <luwei.kang@xxxxxxxxx>
---
arch/x86/kvm/vmx.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3c9ce3e..58606ce 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7076,6 +7076,20 @@ static __init int hardware_setup(void)
if (pt_mode == PT_MODE_GUEST)
pt_register_virt_ops(&pt_virt_ops);

+ if (pt_mode == PT_MODE_GUEST || pt_mode == PT_MODE_HOST_GUEST) {
+ u32 i, eax, ebx, ecx, edx;
+
+ cpuid_count(0x14, 1, &eax, &ebx, &ecx, &edx);
+ vmx_disable_intercept_for_msr(MSR_IA32_RTIT_CTL, false);
+ vmx_disable_intercept_for_msr(MSR_IA32_RTIT_STATUS, false);
+ vmx_disable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_BASE, false);
+ vmx_disable_intercept_for_msr(MSR_IA32_RTIT_OUTPUT_MASK, false);
+ vmx_disable_intercept_for_msr(MSR_IA32_RTIT_CR3_MATCH, false);
+ for (i = 0; i < (eax & 0x7); i++)
+ vmx_disable_intercept_for_msr(MSR_IA32_RTIT_ADDR0_A + i,
+ false);
+ }
+
return alloc_kvm_area();

out:
--
1.8.3.1