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| author | Peter Zijlstra <peterz@infradead.org> | 2012-09-13 14:59:14 -0600 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2012-10-16 12:43:58 -0300 |
| commit | 20b279ddb38ca42f8863cec07b4d45ec24589f13 (patch) | |
| tree | 993ddf58189bc665e0f392042321770e488e123d | |
| parent | 1342798cc13e3b48d9b5738f0c8fa812ccea8101 (diff) | |
| download | op-kernel-dev-20b279ddb38ca42f8863cec07b4d45ec24589f13.zip op-kernel-dev-20b279ddb38ca42f8863cec07b4d45ec24589f13.tar.gz | |
perf: Require exclude_guest to use PEBS - kernel side enforcement
Intel PEBS in VT-x context uses the DS address as a guest linear
address, even though its programmed by the host as a host linear
address. This either results in guest memory corruption and or the
hardware faulting and 'crashing' the virtual machine. Therefore we have
to disable PEBS on VT-x enter and re-enable on VT-x exit, enforcing a
strict exclude_guest.
This patch enforces exclude_guest kernel side.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Robert Richter <robert.richter@amd.com>
Link: http://lkml.kernel.org/r/1347569955-54626-3-git-send-email-dsahern@gmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | arch/x86/kernel/cpu/perf_event.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 915b876..3373f84 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -338,6 +338,9 @@ int x86_setup_perfctr(struct perf_event *event) /* BTS is currently only allowed for user-mode. */ if (!attr->exclude_kernel) return -EOPNOTSUPP; + + if (!attr->exclude_guest) + return -EOPNOTSUPP; } hwc->config |= config; @@ -380,6 +383,9 @@ int x86_pmu_hw_config(struct perf_event *event) if (event->attr.precise_ip) { int precise = 0; + if (!event->attr.exclude_guest) + return -EOPNOTSUPP; + /* Support for constant skid */ if (x86_pmu.pebs_active && !x86_pmu.pebs_broken) { precise++; |
