From: Sean Christopherson <seanjc@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, Like Xu <like.xu.linux@gmail.com>
Subject: [PATCH v4 4/5] KVM: VMX: Fold vmx_supported_debugctl() into vcpu_supported_debugctl()
Date: Thu, 1 Sep 2022 17:32:57 +0000 [thread overview]
Message-ID: <20220901173258.925729-5-seanjc@google.com> (raw)
In-Reply-To: <20220901173258.925729-1-seanjc@google.com>
Fold vmx_supported_debugctl() into vcpu_supported_debugctl(), its only
caller. Setting bits only to clear them a few instructions later is
rather silly, and splitting the logic makes things seem more complicated
than they actually are.
Opportunistically drop DEBUGCTLMSR_LBR_MASK now that there's a single
reference to the pair of bits. The extra layer of indirection provides
no meaningful value and makes it unnecessarily tedious to understand
what KVM is doing.
No functional change.
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/vmx/capabilities.h | 15 ---------------
arch/x86/kvm/vmx/vmx.c | 12 +++++++-----
2 files changed, 7 insertions(+), 20 deletions(-)
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 23dca5ebae16..189a64a6e139 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -24,8 +24,6 @@ extern int __read_mostly pt_mode;
#define PMU_CAP_FW_WRITES (1ULL << 13)
#define PMU_CAP_LBR_FMT 0x3f
-#define DEBUGCTLMSR_LBR_MASK (DEBUGCTLMSR_LBR | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI)
-
struct nested_vmx_msrs {
/*
* We only store the "true" versions of the VMX capability MSRs. We
@@ -403,19 +401,6 @@ static inline bool vmx_pebs_supported(void)
return boot_cpu_has(X86_FEATURE_PEBS) && kvm_pmu_cap.pebs_ept;
}
-static inline u64 vmx_supported_debugctl(void)
-{
- u64 debugctl = 0;
-
- if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT))
- debugctl |= DEBUGCTLMSR_BUS_LOCK_DETECT;
-
- if (vmx_get_perf_capabilities() & PMU_CAP_LBR_FMT)
- debugctl |= DEBUGCTLMSR_LBR_MASK;
-
- return debugctl;
-}
-
static inline bool cpu_has_notify_vmexit(void)
{
return vmcs_config.cpu_based_2nd_exec_ctrl &
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 657fa9908bf9..a5e3c1e6aa2b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2030,13 +2030,15 @@ static u64 nested_vmx_truncate_sysenter_addr(struct kvm_vcpu *vcpu,
static u64 vcpu_supported_debugctl(struct kvm_vcpu *vcpu)
{
- u64 debugctl = vmx_supported_debugctl();
+ u64 debugctl = 0;
- if (!intel_pmu_lbr_is_enabled(vcpu))
- debugctl &= ~DEBUGCTLMSR_LBR_MASK;
+ if (boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT) &&
+ guest_cpuid_has(vcpu, X86_FEATURE_BUS_LOCK_DETECT))
+ debugctl |= DEBUGCTLMSR_BUS_LOCK_DETECT;
- if (!guest_cpuid_has(vcpu, X86_FEATURE_BUS_LOCK_DETECT))
- debugctl &= ~DEBUGCTLMSR_BUS_LOCK_DETECT;
+ if ((vmx_get_perf_capabilities() & PMU_CAP_LBR_FMT) &&
+ intel_pmu_lbr_is_enabled(vcpu))
+ debugctl |= DEBUGCTLMSR_LBR | DEBUGCTLMSR_FREEZE_LBRS_ON_PMI;
return debugctl;
}
--
2.37.2.789.g6183377224-goog
next prev parent reply other threads:[~2022-09-01 17:33 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-01 17:32 [PATCH v4 0/5] KVM: x86: Intel LBR related perf cleanups Sean Christopherson
2022-09-01 17:32 ` [PATCH v4 1/5] perf/x86/core: Remove unnecessary stubs provided for KVM-only helpers Sean Christopherson
2022-09-02 2:39 ` kernel test robot
2022-09-02 2:53 ` kernel test robot
2022-09-02 2:54 ` kernel test robot
2022-09-01 17:32 ` [PATCH v4 2/5] perf/x86/core: Drop the unnecessary return value from x86_perf_get_lbr() Sean Christopherson
2022-09-01 17:32 ` [PATCH v4 3/5] KVM: VMX: Move vmx_get_perf_capabilities() definition to vmx.c Sean Christopherson
2022-09-01 17:32 ` Sean Christopherson [this message]
2022-09-01 17:32 ` [PATCH v4 5/5] KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs Sean Christopherson
2022-09-08 13:45 ` [PATCH v4 0/5] KVM: x86: Intel LBR related perf cleanups Peter Zijlstra
2022-09-17 1:11 ` Sean Christopherson
2022-10-03 17:22 ` 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=20220901173258.925729-5-seanjc@google.com \
--to=seanjc@google.com \
--cc=acme@kernel.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=jolsa@kernel.org \
--cc=kvm@vger.kernel.org \
--cc=like.xu.linux@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
/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).