[PATCH 05/33] perf, kvm: Support the intx/intx_cp modifiers in KVM arch perfmon emulation v3

Andi Kleen
2012-10-26T20:36:57Z

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
Cc: gleb@redhat.com
v2: Various fixes to address review feedback
v3: Ignore the bits when no CPUID. No #GP. Force raw events with TSX bits.
Cc: gleb@redhat.com
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/pmu.c | 34 ++++++++++++++++++++++++++--------
2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index b2e11f4..6783289 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -318,6 +318,7 @@ struct kvm_pmu {
u64 global_ovf_ctrl;
u64 counter_bitmask[2];
u64 global_ctrl_mask;
+ u64 cpuid_word9;
u8 version;
struct kvm_pmc gp_counters[INTEL_PMC_MAX_GENERIC];
struct kvm_pmc fixed_counters[INTEL_PMC_MAX_FIXED];
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index cfc258a..8bc954a 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);

@@ -206,7 +211,8 @@ static unsigned find_arch_event(struct kvm_pmu *pmu, u8 event_select,
return arch_events[i].event_type;
}

-static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
+static void reprogram_gp_counter(struct kvm_pmu *pmu, struct kvm_pmc *pmc,
+ u64 eventsel)
{
unsigned config, type = PERF_TYPE_RAW;
u8 event_select, unit_mask;
@@ -224,9 +230,16 @@ static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
event_select = eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
unit_mask = (eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;

+ if (!(boot_cpu_has(X86_FEATURE_HLE) ||
+ boot_cpu_has(X86_FEATURE_RTM)) ||
+ !(pmu->cpuid_word9 & (X86_FEATURE_HLE|X86_FEATURE_RTM)))
+ eventsel &= ~(HSW_INTX|HSW_INTX_CHECKPOINTED);
+
if (!(eventsel & (ARCH_PERFMON_EVENTSEL_EDGE |
ARCH_PERFMON_EVENTSEL_INV |
- ARCH_PERFMON_EVENTSEL_CMASK))) {
+ ARCH_PERFMON_EVENTSEL_CMASK |
+ HSW_INTX |
+ HSW_INTX_CHECKPOINTED))) {
config = find_arch_event(&pmc->vcpu->arch.pmu, event_select,
unit_mask);
if (config != PERF_COUNT_HW_MAX)
@@ -239,7 +252,9 @@ 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));
}

static void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 en_pmi, int idx)
@@ -256,7 +271,7 @@ 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)
@@ -289,7 +304,7 @@ static void reprogram_idx(struct kvm_pmu *pmu, int idx)
return;

if (pmc_is_gp(pmc))
- reprogram_gp_counter(pmc, pmc->eventsel);
+ reprogram_gp_counter(pmu, pmc, pmc->eventsel);
else {
int fidx = idx - INTEL_PMC_IDX_FIXED;
reprogram_fixed_counter(pmc,
@@ -400,8 +415,8 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data)
} else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) {
if (data == pmc->eventsel)
return 0;
- if (!(data & 0xffffffff00200000ull)) {
- reprogram_gp_counter(pmc, data);
+ if (!(data & 0xfffffffc00200000ull)) {
+ reprogram_gp_counter(pmu, pmc, data);
return 0;
}
}
@@ -470,6 +485,9 @@ void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu)
pmu->global_ctrl = ((1 << pmu->nr_arch_gp_counters) - 1) |
(((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED);
pmu->global_ctrl_mask = ~pmu->global_ctrl;
+
+ entry = kvm_find_cpuid_entry(vcpu, 7, 0);
+ pmu->cpuid_word9 = entry ? entry->ebx : 0;
}

void kvm_pmu_init(struct kvm_vcpu *vcpu)
--
1.7.7.6