From acb48d9d34838d927830b9c956ecee083c3fce7f Mon Sep 17 00:00:00 2001
From: Eric Hankland <ehankland@google.com>
Date: Tue, 27 Sep 2022 14:56:49 +0800
Subject: [PATCH] KVM: x86: Adjust counter sample period after a wrmsr
mainline inclusion
from mainline-v5.6
commit 168d918f2643d7d3f0240e768d40b4f8aba3540a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5SDUS
CVE: NA
-------------
The sample_period of a counter tracks when that counter will
overflow and set global status/trigger a PMI. However this currently
only gets set when the initial counter is created or when a counter is
resumed; this updates the sample period after a wrmsr so running
counters will accurately reflect their new value.
Signed-off-by: Eric Hankland <ehankland@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
[Yanan Wang: Adapt the code to linux v4.19]
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>
---
arch/x86/kvm/pmu.c | 2 +-
arch/x86/kvm/pmu.h | 9 +++++++++
arch/x86/kvm/pmu_intel.c | 6 ++++++
3 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index acc8d217f656..4fe0bfcf0304 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -113,7 +113,7 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type,
.config = config,
};
- attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc);
+ attr.sample_period = get_sample_period(pmc, pmc->counter);
if (in_tx)
attr.config |= HSW_IN_TX;
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 22dff661145a..273d4146fb28 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -103,6 +103,15 @@ static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
return NULL;
}
+static inline u64 get_sample_period(struct kvm_pmc *pmc, u64 counter_value)
+{
+ u64 sample_period = (-counter_value) & pmc_bitmask(pmc);
+
+ if (!sample_period)
+ sample_period = pmc_bitmask(pmc) + 1;
+ return sample_period;
+}
+
void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel);
void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 ctrl, int fixed_idx);
void reprogram_counter(struct kvm_pmu *pmu, int pmc_idx);
diff --git a/arch/x86/kvm/pmu_intel.c b/arch/x86/kvm/pmu_intel.c
index 2bdc8a5775ee..29479bc27294 100644
--- a/arch/x86/kvm/pmu_intel.c
+++ b/arch/x86/kvm/pmu_intel.c
@@ -244,9 +244,15 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
if (!msr_info->host_initiated)
data = (s64)(s32)data;
pmc->counter += data - pmc_read_counter(pmc);
+ if (pmc->perf_event)
+ perf_event_period(pmc->perf_event,
+ get_sample_period(pmc, data));
return 0;
} else if ((pmc = get_fixed_pmc(pmu, msr))) {
pmc->counter += data - pmc_read_counter(pmc);
+ if (pmc->perf_event)
+ perf_event_period(pmc->perf_event,
+ get_sample_period(pmc, data));
return 0;
} else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
if (data == pmc->eventsel)
--
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