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SubjectRe: [06/31] perf, kvm: Support the intx/intx_cp modifiers in KVM arch perfmon emulation
On Tue, Oct 02, 2012 at 11:48:26PM -0000, Andi Kleen wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> This is not arch perfmon, but older CPUs will just ignore it. This makes
> it possible to do at least some TSX measurements from a KVM guest
>
> Cc: avi@redhat.com
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
>
> ---
> arch/x86/kvm/pmu.c | 13 ++++++++++---
> 1 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
> index 9b7ec11..f72a409 100644
> --- a/arch/x86/kvm/pmu.c
> +++ b/arch/x86/kvm/pmu.c
> @@ -160,7 +160,7 @@ static void stop_counter(struct kvm_pmc *pmc)
>
> static void reprogram_counter(struct kvm_pmc *pmc, u32 type,
> unsigned config, bool exclude_user, bool exclude_kernel,
> - bool intr)
> + bool intr, bool intx, bool intx_cp)
> {
> struct perf_event *event;
> struct perf_event_attr attr = {
> @@ -173,6 +173,11 @@ static void reprogram_counter(struct kvm_pmc *pmc, u32 type,
> .exclude_kernel = exclude_kernel,
> .config = config,
> };
> + /* Will be ignored on CPUs that don't support this. */
> + if (intx)
> + attr.config |= HSW_INTX;
> + if (intx_cp)
> + attr.config |= HSW_INTX_CHECKPOINTED;
>
> attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc);
>
> @@ -239,7 +244,9 @@ static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
> reprogram_counter(pmc, type, config,
> !(eventsel & ARCH_PERFMON_EVENTSEL_USR),
> !(eventsel & ARCH_PERFMON_EVENTSEL_OS),
> - eventsel & ARCH_PERFMON_EVENTSEL_INT);
> + eventsel & ARCH_PERFMON_EVENTSEL_INT,
> + !!(eventsel & HSW_INTX),
> + !!(eventsel & HSW_INTX_CHECKPOINTED));
Before reprogram_gp_counter() is called from kvm_pmu_set_msr() eventsel
is checked for reserved bits. Both HSW_INTX and HSW_INTX_CHECKPOINTED
are marked as reserved currently. Reserved bit mask should depend on
cpuid bits provided to a guest.

> }
>
> static void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 en_pmi, int idx)
> @@ -256,7 +263,7 @@ static void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 en_pmi, int idx)
> arch_events[fixed_pmc_events[idx]].event_type,
> !(en & 0x2), /* exclude user */
> !(en & 0x1), /* exclude kernel */
> - pmi);
> + pmi, false, false);
> }
>
> static inline u8 fixed_en_pmi(u64 ctrl, int idx)

--
Gleb.


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