From: Marc Zyngier <marc.zyngier@arm.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>
Cc: Andre Przywara <andre.przywara@arm.com>,
Andrew Murray <andrew.murray@arm.com>,
Dave Martin <Dave.Martin@arm.com>,
Eric Auger <eric.auger@redhat.com>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry@arm.com>,
Steven Price <steven.price@arm.com>,
Sudeep Holla <sudeep.holla@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH 12/18] KVM: arm/arm64: Remove pmc->bitmask
Date: Tue, 9 Jul 2019 13:25:01 +0100 [thread overview]
Message-ID: <20190709122507.214494-13-marc.zyngier@arm.com> (raw)
In-Reply-To: <20190709122507.214494-1-marc.zyngier@arm.com>
From: Andrew Murray <andrew.murray@arm.com>
We currently use pmc->bitmask to determine the width of the pmc - however
it's superfluous as the pmc index already describes if the pmc is a cycle
counter or event counter. The architecture clearly describes the widths of
these counters.
Let's remove the bitmask to simplify the code.
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
include/kvm/arm_pmu.h | 1 -
virt/kvm/arm/pmu.c | 30 ++++++++++++++++++++----------
2 files changed, 20 insertions(+), 11 deletions(-)
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 45e5205750b4..48a15d4b820e 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -17,7 +17,6 @@
struct kvm_pmc {
u8 idx; /* index into the pmu->pmc array */
struct perf_event *perf_event;
- u64 bitmask;
};
struct kvm_pmu {
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index f77643f4274c..24c6cf869a16 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -14,6 +14,18 @@
#include <kvm/arm_vgic.h>
static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx);
+
+/**
+ * kvm_pmu_idx_is_64bit - determine if select_idx is a 64bit counter
+ * @vcpu: The vcpu pointer
+ * @select_idx: The counter index
+ */
+static bool kvm_pmu_idx_is_64bit(struct kvm_vcpu *vcpu, u64 select_idx)
+{
+ return (select_idx == ARMV8_PMU_CYCLE_IDX &&
+ __vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_LC);
+}
+
/**
* kvm_pmu_get_counter_value - get PMU counter value
* @vcpu: The vcpu pointer
@@ -36,7 +48,10 @@ u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
counter += perf_event_read_value(pmc->perf_event, &enabled,
&running);
- return counter & pmc->bitmask;
+ if (!kvm_pmu_idx_is_64bit(vcpu, select_idx))
+ counter = lower_32_bits(counter);
+
+ return counter;
}
/**
@@ -102,7 +117,6 @@ void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu)
for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]);
pmu->pmc[i].idx = i;
- pmu->pmc[i].bitmask = 0xffffffffUL;
}
}
@@ -337,8 +351,6 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
*/
void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
{
- struct kvm_pmu *pmu = &vcpu->arch.pmu;
- struct kvm_pmc *pmc;
u64 mask;
int i;
@@ -357,11 +369,6 @@ void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val)
for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++)
kvm_pmu_set_counter_value(vcpu, i, 0);
}
-
- if (val & ARMV8_PMU_PMCR_LC) {
- pmc = &pmu->pmc[ARMV8_PMU_CYCLE_IDX];
- pmc->bitmask = 0xffffffffffffffffUL;
- }
}
static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx)
@@ -409,7 +416,10 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)
counter = kvm_pmu_get_counter_value(vcpu, select_idx);
/* The initial sample period (overflow count) of an event. */
- attr.sample_period = (-counter) & pmc->bitmask;
+ if (kvm_pmu_idx_is_64bit(vcpu, pmc->idx))
+ attr.sample_period = (-counter) & GENMASK(63, 0);
+ else
+ attr.sample_period = (-counter) & GENMASK(31, 0);
event = perf_event_create_kernel_counter(&attr, -1, current,
kvm_pmu_perf_overflow, pmc);
--
2.20.1
next prev parent reply other threads:[~2019-07-09 12:25 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-09 12:24 [GIT PULL] KVM/arm updates for Linux 5.3 Marc Zyngier
2019-07-09 12:24 ` [PATCH 01/18] arm64: assembler: Switch ESB-instruction with a vanilla nop if !ARM64_HAS_RAS Marc Zyngier
2019-07-09 12:24 ` [PATCH 02/18] KVM: arm64: Abstract the size of the HYP vectors pre-amble Marc Zyngier
2019-07-09 12:24 ` [PATCH 03/18] KVM: arm64: Make indirect vectors preamble behaviour symmetric Marc Zyngier
2019-07-09 12:24 ` [PATCH 04/18] KVM: arm64: Consume pending SError as early as possible Marc Zyngier
2019-07-09 12:24 ` [PATCH 05/18] KVM: arm64: Defer guest entry when an asynchronous exception is pending Marc Zyngier
2019-07-09 12:24 ` [PATCH 06/18] arm64: Update silicon-errata.txt for Neoverse-N1 #1349291 Marc Zyngier
2019-07-09 12:24 ` [PATCH 07/18] KVM: arm64: Re-mask SError after the one instruction window Marc Zyngier
2019-07-09 12:24 ` [PATCH 08/18] KVM: arm64: Skip more of the SError vaxorcism Marc Zyngier
2019-07-09 12:24 ` [PATCH 09/18] KVM: arm/arm64: Rename kvm_pmu_{enable/disable}_counter functions Marc Zyngier
2019-07-09 12:24 ` [PATCH 10/18] KVM: arm/arm64: Extract duplicated code to own function Marc Zyngier
2019-07-09 12:25 ` [PATCH 11/18] KVM: arm/arm64: Re-create event when setting counter value Marc Zyngier
2019-07-09 12:25 ` Marc Zyngier [this message]
2019-07-09 12:25 ` [PATCH 13/18] KVM: arm/arm64: Support chained PMU counters Marc Zyngier
2019-07-09 12:25 ` [PATCH 14/18] arm64: KVM: Propagate full Spectre v2 workaround state to KVM guests Marc Zyngier
2019-07-09 12:25 ` [PATCH 15/18] KVM: arm/arm64: Add save/restore support for firmware workaround state Marc Zyngier
2019-07-09 12:25 ` [PATCH 16/18] KVM: doc: Add API documentation on the KVM_REG_ARM_WORKAROUNDS register Marc Zyngier
2019-07-09 12:25 ` [PATCH 17/18] KVM: arm64: Migrate _elx sysreg accessors to msr_s/mrs_s Marc Zyngier
2019-07-09 12:25 ` [PATCH 18/18] KVM: arm/arm64: Initialise host's MPIDRs by reading the actual register Marc Zyngier
2019-07-11 13:40 ` [GIT PULL] KVM/arm updates for Linux 5.3 Paolo Bonzini
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