[PATCH 08/15] perf, kvm: Support the intx/intx_cp modifiers in KVM arch perfmon emulation v5

Andi Kleen
2013-04-20T19:21:53Z

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: 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.
v4: Use reserved bits for #GP
v5: Remove obsolete argument
Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/pmu.c | 25 ++++++++++++++++++++-----
2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4979778..7c7e207 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -315,6 +315,7 @@ struct kvm_pmu {
u64 global_ovf_ctrl;
u64 counter_bitmask[2];
u64 global_ctrl_mask;
+ u64 reserved_bits;
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..9317c43 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 +173,10 @@ static void reprogram_counter(struct kvm_pmc *pmc, u32 type,
.exclude_kernel = exclude_kernel,
.config = config,
};
+ if (intx)
+ attr.config |= HSW_INTX;
+ if (intx_cp)
+ attr.config |= HSW_INTX_CHECKPOINTED;

attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc);

@@ -226,7 +230,9 @@ static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)

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 +245,9 @@ 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 +264,7 @@ 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)
@@ -400,7 +408,7 @@ 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)) {
+ if (!(data & pmu->reserved_bits)) {
reprogram_gp_counter(pmc, data);
return 0;
}
@@ -442,6 +450,7 @@ void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu)
pmu->counter_bitmask[KVM_PMC_GP] = 0;
pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
pmu->version = 0;
+ pmu->reserved_bits = 0xffffffff00200000ull;

entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
if (!entry)
@@ -470,6 +479,12 @@ 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);
+ if (entry &&
+ (boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) &&
+ (entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM)))
+ pmu->reserved_bits ^= HSW_INTX|HSW_INTX_CHECKPOINTED;
}

void kvm_pmu_init(struct kvm_vcpu *vcpu)
--
1.7.7.6