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| author |   Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2016-03-29 17:43:10 +0300 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2016-04-28 10:32:42 +0200 |
| commit | 1c5ac21a0e9bab7fc45d0ba9e11623e9ad99d02e (patch) | |
| tree | e17bdbe1029aa8ff7a8efa77874947e5b3caa901 /arch/x86/kvm | |
| parent | perf/core: Fix perf_event_open() vs. execve() race (diff) | |
| download | linux-dev-1c5ac21a0e9bab7fc45d0ba9e11623e9ad99d02e.tar.xz linux-dev-1c5ac21a0e9bab7fc45d0ba9e11623e9ad99d02e.zip | |
perf/x86/intel/pt: Don't die on VMXON
Some versions of Intel PT do not support tracing across VMXON, more
specifically, VMXON will clear TraceEn control bit and any attempt to
set it before VMXOFF will throw a #GP, which in the current state of
things will crash the kernel. Namely:
$ perf record -e intel_pt// kvm -nographic
on such a machine will kill it.
To avoid this, notify the intel_pt driver before VMXON and after
VMXOFF so that it knows when not to enable itself.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/87oa9dwrfk.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/vmx.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index ee1c8a93871c..133679d520af 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3103,6 +3103,8 @@ static __init int vmx_disabled_by_bios(void) static void kvm_cpu_vmxon(u64 addr) { + intel_pt_handle_vmx(1); + asm volatile (ASM_VMX_VMXON_RAX : : "a"(&addr), "m"(addr) : "memory", "cc"); @@ -3172,6 +3174,8 @@ static void vmclear_local_loaded_vmcss(void) static void kvm_cpu_vmxoff(void) { asm volatile (__ex(ASM_VMX_VMXOFF) : : : "cc"); + + intel_pt_handle_vmx(0); } static void hardware_disable(void) |