From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>,
Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 03/26] KVM: x86: Snapshot MSR index in a local variable when processing lists
Date: Wed, 05 Feb 2020 15:31:51 +0100 [thread overview]
Message-ID: <87h805ksvc.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20200129234640.8147-4-sean.j.christopherson@intel.com>
Sean Christopherson <sean.j.christopherson@intel.com> writes:
> Snapshot the MSR index when processing the virtualized and emulated MSR
> lists in kvm_init_msr_list() to improve code readability, particularly
> in the RTIT and PerfMon MSR checks.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> ---
> arch/x86/kvm/x86.c | 22 +++++++++++++---------
> 1 file changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 24597526b5de..3d4a5326d84e 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -5214,7 +5214,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
> static void kvm_init_msr_list(void)
> {
> struct x86_pmu_capability x86_pmu;
> - u32 dummy[2];
> + u32 dummy[2], msr_index;
> unsigned i;
>
> BUILD_BUG_ON_MSG(INTEL_PMC_MAX_FIXED != 4,
> @@ -5227,14 +5227,16 @@ static void kvm_init_msr_list(void)
> num_msr_based_features = 0;
>
> for (i = 0; i < ARRAY_SIZE(msrs_to_save_all); i++) {
> - if (rdmsr_safe(msrs_to_save_all[i], &dummy[0], &dummy[1]) < 0)
> + msr_index = msrs_to_save_all[i];
> +
> + if (rdmsr_safe(msr_index, &dummy[0], &dummy[1]) < 0)
> continue;
>
> /*
> * Even MSRs that are valid in the host may not be exposed
> * to the guests in some cases.
> */
> - switch (msrs_to_save_all[i]) {
> + switch (msr_index) {
> case MSR_IA32_BNDCFGS:
> if (!kvm_mpx_supported())
> continue;
> @@ -5262,17 +5264,17 @@ static void kvm_init_msr_list(void)
> break;
> case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
> if (!kvm_x86_ops->pt_supported() ||
> - msrs_to_save_all[i] - MSR_IA32_RTIT_ADDR0_A >=
> + msr_index - MSR_IA32_RTIT_ADDR0_A >=
> intel_pt_validate_hw_cap(PT_CAP_num_address_ranges) * 2)
> continue;
> break;
> case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 17:
> - if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
> + if (msr_index - MSR_ARCH_PERFMON_PERFCTR0 >=
> min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp))
> continue;
> break;
> case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 17:
> - if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
> + if (msr_index - MSR_ARCH_PERFMON_EVENTSEL0 >=
> min(INTEL_PMC_MAX_GENERIC, x86_pmu.num_counters_gp))
> continue;
> break;
> @@ -5280,14 +5282,16 @@ static void kvm_init_msr_list(void)
> break;
> }
>
> - msrs_to_save[num_msrs_to_save++] = msrs_to_save_all[i];
> + msrs_to_save[num_msrs_to_save++] = msr_index;
> }
>
> for (i = 0; i < ARRAY_SIZE(emulated_msrs_all); i++) {
> - if (!kvm_x86_ops->has_emulated_msr(emulated_msrs_all[i]))
> + msr_index = emulated_msrs_all[i];
> +
> + if (!kvm_x86_ops->has_emulated_msr(msr_index))
> continue;
>
> - emulated_msrs[num_emulated_msrs++] = emulated_msrs_all[i];
> + emulated_msrs[num_emulated_msrs++] = msr_index;
> }
>
> for (i = 0; i < ARRAY_SIZE(msr_based_features_all); i++) {
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
--
Vitaly
next prev parent reply other threads:[~2020-02-05 14:32 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-29 23:46 [PATCH 00/26] KVM: x86: Purge kvm_x86_ops->*_supported() Sean Christopherson
2020-01-29 23:46 ` [PATCH 01/26] KVM: x86: Remove superfluous brackets from case statement Sean Christopherson
2020-02-05 14:29 ` Vitaly Kuznetsov
2020-02-05 14:32 ` Sean Christopherson
2020-01-29 23:46 ` [PATCH 02/26] KVM: x86: Take an unsigned 32-bit int for has_emulated_msr()'s index Sean Christopherson
2020-02-05 14:30 ` Vitaly Kuznetsov
2020-01-29 23:46 ` [PATCH 03/26] KVM: x86: Snapshot MSR index in a local variable when processing lists Sean Christopherson
2020-02-05 14:31 ` Vitaly Kuznetsov [this message]
2020-01-29 23:46 ` [PATCH 04/26] KVM: x86: Add a kvm_x86_ops hook to query virtualized MSR support Sean Christopherson
2020-02-05 14:34 ` Vitaly Kuznetsov
2020-02-05 14:59 ` Sean Christopherson
2020-02-05 15:22 ` Vitaly Kuznetsov
2020-02-05 15:35 ` Sean Christopherson
2020-02-05 16:55 ` Vitaly Kuznetsov
2020-02-05 17:02 ` Sean Christopherson
2020-02-06 12:08 ` Vitaly Kuznetsov
2020-01-29 23:46 ` [PATCH 05/26] KVM: x86: Move MSR_TSC_AUX existence checks into vendor code Sean Christopherson
2020-02-05 14:39 ` Vitaly Kuznetsov
2020-01-29 23:46 ` [PATCH 06/26] KVM: x86: Move MSR_IA32_BNDCFGS " Sean Christopherson
2020-02-05 14:53 ` Vitaly Kuznetsov
2020-01-29 23:46 ` [PATCH 07/26] KVM: VMX: Add helpers to query Intel PT mode Sean Christopherson
2020-01-29 23:46 ` [PATCH 08/26] KVM: x86: Move RTIT (Intel PT) MSR existence checks into vendor code Sean Christopherson
2020-01-29 23:46 ` [PATCH 09/26] KVM: x86: Calculate the supported xcr0 mask at load time Sean Christopherson
2020-01-29 23:46 ` [PATCH 10/26] KVM: x86: Use supported_xcr0 to detect MPX support Sean Christopherson
2020-01-29 23:46 ` [PATCH 11/26] KVM: x86: Make kvm_mpx_supported() an inline function Sean Christopherson
2020-01-29 23:46 ` [PATCH 12/26] KVM: x86: Drop explicit @func param from ->set_supported_cpuid() Sean Christopherson
2020-01-29 23:46 ` [PATCH 13/26] KVM: x86: Use u32 for holding CPUID register value in helpers Sean Christopherson
2020-01-29 23:46 ` [PATCH 14/26] KVM: x86: Introduce cpuid_entry_{get,has}() accessors Sean Christopherson
2020-01-29 23:46 ` [PATCH 15/26] KVM: x86: Introduce cpuid_entry_{change,set,clear}() mutators Sean Christopherson
2020-01-29 23:46 ` [PATCH 16/26] KVM: x86: Add Kconfig-controlled auditing of reverse CPUID lookups Sean Christopherson
2020-01-29 23:46 ` [PATCH 17/26] KVM: x86: Handle MPX CPUID adjustment in vendor code Sean Christopherson
2020-01-29 23:46 ` [PATCH 18/26] KVM: x86: Handle INVPCID " Sean Christopherson
2020-01-29 23:46 ` [PATCH 19/26] KVM: x86: Handle UMIP emulation CPUID adjustment in VMX code Sean Christopherson
2020-01-29 23:46 ` [PATCH 20/26] KVM: x86: Handle PKU CPUID adjustment in SVM code Sean Christopherson
2020-01-29 23:46 ` [PATCH 21/26] KVM: x86: Handle RDTSCP CPUID adjustment in VMX code Sean Christopherson
2020-01-29 23:46 ` [PATCH 22/26] KVM: x86: Handle XSAVES " Sean Christopherson
2020-01-29 23:46 ` [PATCH 23/26] KVM: x86: Handle Intel PT CPUID adjustment in vendor code Sean Christopherson
2020-01-29 23:46 ` [PATCH 24/26] KVM: x86: Clear output regs for CPUID 0x14 if PT isn't exposed to guest Sean Christopherson
2020-01-29 23:46 ` [PATCH 25/26] KVM: x86: Handle main Intel PT CPUID leaf in vendor code Sean Christopherson
2020-01-30 0:38 ` Sean Christopherson
2020-01-29 23:46 ` [PATCH 26/26] KVM: VMX: Directly query Intel PT mode when refreshing PMUs Sean Christopherson
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