| Message ID | 1509401117-15521-9-git-send-email-luwei.kang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 30/10/2017 23:05, Luwei Kang wrote: > From: Chao Peng <chao.p.peng@linux.intel.com> > > Pass through Intel processor trace to guest directly. > > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > Signed-off-by: Luwei Kang <luwei.kang@intel.com> > --- > arch/x86/kvm/vmx.c | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 8f61a8d..01447e2 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -7029,6 +7029,19 @@ static __init int hardware_setup(void) > !cpu_has_vmx_intel_pt() || !cpu_has_vmx_pt_use_gpa()) > pt_mode = PT_MODE_SYSTEM; > > + if (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_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); > + } > + As I mentioned earlier, this probably makes vmentry/vmexit too expensive when guests are not using processor tracing. I would do it only if guest TRACEEN=1 (since anyway the values have to be correct if guest TRACEEN=1, and a change in TRACEEN always causes a vmexit). Paolo > return alloc_kvm_area(); > > out: >
> > + if (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_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); > > + } > > + > > As I mentioned earlier, this probably makes vmentry/vmexit too expensive when guests are not using processor tracing. I would do it only if guest TRACEEN=1 (since anyway the values have to be correct if guest TRACEEN=1, and a change in TRACEEN always causes a vmexit). > Will change in next version. Thanks, Luwei Kang > > > return alloc_kvm_area(); > > > > out: > >
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8f61a8d..01447e2 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -7029,6 +7029,19 @@ static __init int hardware_setup(void) !cpu_has_vmx_intel_pt() || !cpu_has_vmx_pt_use_gpa()) pt_mode = PT_MODE_SYSTEM; + if (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_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: