From: Like Xu <like.xu.linux@gmail.com>
To: Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 3/8] KVM: x86/pmu: Rewrite reprogram_counters() to improve performance
Date: Fri, 11 Nov 2022 18:26:40 +0800 [thread overview]
Message-ID: <20221111102645.82001-4-likexu@tencent.com> (raw)
In-Reply-To: <20221111102645.82001-1-likexu@tencent.com>
From: Like Xu <likexu@tencent.com>
A valid pmc is always tested before using pmu->reprogram_pmi. Eliminate
this part of the redundancy by setting the counter's bitmask directly,
and in addition, trigger KVM_REQ_PMU only once to save more cpu cycles.
Signed-off-by: Like Xu <likexu@tencent.com>
---
arch/x86/kvm/pmu.h | 11 +++++++++++
arch/x86/kvm/vmx/pmu_intel.c | 12 ------------
2 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 2b5376ba66ea..be552c8217a0 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -189,6 +189,17 @@ static inline void kvm_pmu_request_counter_reprogam(struct kvm_pmc *pmc)
kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
}
+static inline void reprogram_counters(struct kvm_pmu *pmu, u64 diff)
+{
+ int bit;
+
+ if (diff) {
+ for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
+ __set_bit(bit, pmu->reprogram_pmi);
+ kvm_make_request(KVM_REQ_PMU, pmu_to_vcpu(pmu));
+ }
+}
+
void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu);
void kvm_pmu_handle_event(struct kvm_vcpu *vcpu);
int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data);
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 2f7cd388859c..db704eea2d7c 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -68,18 +68,6 @@ static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
}
}
-static void reprogram_counters(struct kvm_pmu *pmu, u64 diff)
-{
- int bit;
- struct kvm_pmc *pmc;
-
- for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX) {
- pmc = intel_pmc_idx_to_pmc(pmu, bit);
- if (pmc)
- kvm_pmu_request_counter_reprogam(pmc);
- }
-}
-
static bool intel_hw_event_available(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
--
2.38.1
next prev parent reply other threads:[~2022-11-11 10:27 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-11 10:26 [PATCH v3 0/8] KVM: x86: Add AMD Guest PerfMonV2 PMU support Like Xu
2022-11-11 10:26 ` [PATCH v3 1/8] KVM: x86/pmu: Rename pmc_is_enabled() to pmc_is_globally_enabled() Like Xu
2023-01-27 2:03 ` Sean Christopherson
2023-02-02 11:46 ` Like Xu
2022-11-11 10:26 ` [PATCH v3 2/8] KVM: VMX: Refactor intel_pmu_set_msr() to align with other set_msr() helpers Like Xu
2023-01-27 2:09 ` Sean Christopherson
2022-11-11 10:26 ` Like Xu [this message]
2023-01-20 1:09 ` [PATCH v3 3/8] KVM: x86/pmu: Rewrite reprogram_counters() to improve performance Sean Christopherson
2023-01-24 20:16 ` Sean Christopherson
2022-11-11 10:26 ` [PATCH v3 4/8] KVM: x86/pmu: Make part of the Intel v2 PMU MSRs handling x86 generic Like Xu
2022-11-11 10:26 ` [PATCH v3 5/8] KVM: x86/cpuid: Add X86_FEATURE_AMD_PMU_V2 as a KVM-only leaf entry Like Xu
2023-01-24 19:47 ` Sean Christopherson
2023-02-06 11:47 ` Like Xu
2023-02-10 1:32 ` Sean Christopherson
2022-11-11 10:26 ` [PATCH v3 6/8] KVM: x86/svm/pmu: Add AMD PerfMonV2 support Like Xu
2023-01-25 0:10 ` Sean Christopherson
2023-02-06 7:53 ` Like Xu
2023-02-06 22:22 ` Sean Christopherson
2022-11-11 10:26 ` [PATCH v3 7/8] KVM: x86/cpuid: Add AMD CPUID ExtPerfMonAndDbg leaf 0x80000022 Like Xu
2023-01-25 0:16 ` Sean Christopherson
2022-11-11 10:26 ` [PATCH v3 8/8] KVM: x86/cpuid: Use fast return for cpuid "0xa" leaf when !enable_pmu Like Xu
2023-01-20 1:11 ` Sean Christopherson
2022-12-06 8:32 ` [PATCH v3 0/8] KVM: x86: Add AMD Guest PerfMonV2 PMU support Like Xu
2023-01-20 1:13 ` Sean Christopherson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221111102645.82001-4-likexu@tencent.com \
--to=like.xu.linux@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).