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From: <gregkh@linuxfoundation.org>
To: likexu@tencent.com, jmattson@google.com, pbonzini@redhat.com,
	vkuznets@redhat.com
Cc: <stable@vger.kernel.org>
Subject: FAILED: patch "[PATCH] KVM: x86/pmu: Do not speculatively query Intel GP PMCs that" failed to apply to 5.15-stable tree
Date: Mon, 14 Nov 2022 11:58:22 +0100	[thread overview]
Message-ID: <1668423502181251@kroah.com> (raw)


The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

Possible dependencies:

8631ef59b622 ("KVM: x86/pmu: Do not speculatively query Intel GP PMCs that don't exist yet")
902caeb6841a ("KVM: x86/pmu: Add PEBS_DATA_CFG MSR emulation to support adaptive PEBS")
8183a538cd95 ("KVM: x86/pmu: Add IA32_DS_AREA MSR emulation to support guest DS")
6ebe44366bde ("KVM: x86/pmu: Adjust precise_ip to emulate Ice Lake guest PDIR counter")
79f3e3b58386 ("KVM: x86/pmu: Reprogram PEBS event to emulate guest PEBS counter")
c59a1f106f5c ("KVM: x86/pmu: Add IA32_PEBS_ENABLE MSR emulation for extended PEBS")
0d23dc34a7ce ("x86/perf/core: Add pebs_capable to store valid PEBS_COUNTER_MASK value")
2c985527dd8d ("KVM: x86/pmu: Introduce the ctrl_mask value for fixed counter")
39a4d779546a ("perf/x86/core: Pass "struct kvm_pmu *" to determine the guest values")
38904911e864 ("Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8631ef59b62290c7d88e7209e35dfb47f33f4902 Mon Sep 17 00:00:00 2001
From: Like Xu <likexu@tencent.com>
Date: Mon, 19 Sep 2022 17:10:06 +0800
Subject: [PATCH] KVM: x86/pmu: Do not speculatively query Intel GP PMCs that
 don't exist yet

The SDM lists an architectural MSR IA32_CORE_CAPABILITIES (0xCF)
that limits the theoretical maximum value of the Intel GP PMC MSRs
allocated at 0xC1 to 14; likewise the Intel April 2022 SDM adds
IA32_OVERCLOCKING_STATUS at 0x195 which limits the number of event
selection MSRs to 15 (0x186-0x194).

Limiting the maximum number of counters to 14 or 18 based on the currently
allocated MSRs is clearly fragile, and it seems likely that Intel will
even place PMCs 8-15 at a completely different range of MSR indices.
So stop at the maximum number of GP PMCs supported today on Intel
processors.

There are some machines, like Intel P4 with non Architectural PMU, that
may indeed have 18 counters, but those counters are in a completely
different MSR address range and are not supported by KVM.

Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Fixes: cf05a67b68b8 ("KVM: x86: omit "impossible" pmu MSRs from MSR list")
Suggested-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Like Xu <likexu@tencent.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20220919091008.60695-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5f5eb577d583..73716fab120f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1442,20 +1442,10 @@ static const u32 msrs_to_save_all[] = {
 	MSR_ARCH_PERFMON_PERFCTR0 + 2, MSR_ARCH_PERFMON_PERFCTR0 + 3,
 	MSR_ARCH_PERFMON_PERFCTR0 + 4, MSR_ARCH_PERFMON_PERFCTR0 + 5,
 	MSR_ARCH_PERFMON_PERFCTR0 + 6, MSR_ARCH_PERFMON_PERFCTR0 + 7,
-	MSR_ARCH_PERFMON_PERFCTR0 + 8, MSR_ARCH_PERFMON_PERFCTR0 + 9,
-	MSR_ARCH_PERFMON_PERFCTR0 + 10, MSR_ARCH_PERFMON_PERFCTR0 + 11,
-	MSR_ARCH_PERFMON_PERFCTR0 + 12, MSR_ARCH_PERFMON_PERFCTR0 + 13,
-	MSR_ARCH_PERFMON_PERFCTR0 + 14, MSR_ARCH_PERFMON_PERFCTR0 + 15,
-	MSR_ARCH_PERFMON_PERFCTR0 + 16, MSR_ARCH_PERFMON_PERFCTR0 + 17,
 	MSR_ARCH_PERFMON_EVENTSEL0, MSR_ARCH_PERFMON_EVENTSEL1,
 	MSR_ARCH_PERFMON_EVENTSEL0 + 2, MSR_ARCH_PERFMON_EVENTSEL0 + 3,
 	MSR_ARCH_PERFMON_EVENTSEL0 + 4, MSR_ARCH_PERFMON_EVENTSEL0 + 5,
 	MSR_ARCH_PERFMON_EVENTSEL0 + 6, MSR_ARCH_PERFMON_EVENTSEL0 + 7,
-	MSR_ARCH_PERFMON_EVENTSEL0 + 8, MSR_ARCH_PERFMON_EVENTSEL0 + 9,
-	MSR_ARCH_PERFMON_EVENTSEL0 + 10, MSR_ARCH_PERFMON_EVENTSEL0 + 11,
-	MSR_ARCH_PERFMON_EVENTSEL0 + 12, MSR_ARCH_PERFMON_EVENTSEL0 + 13,
-	MSR_ARCH_PERFMON_EVENTSEL0 + 14, MSR_ARCH_PERFMON_EVENTSEL0 + 15,
-	MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17,
 	MSR_IA32_PEBS_ENABLE, MSR_IA32_DS_AREA, MSR_PEBS_DATA_CFG,
 
 	MSR_K7_EVNTSEL0, MSR_K7_EVNTSEL1, MSR_K7_EVNTSEL2, MSR_K7_EVNTSEL3,
@@ -7041,12 +7031,12 @@ static void kvm_init_msr_list(void)
 				intel_pt_validate_hw_cap(PT_CAP_num_address_ranges) * 2)
 				continue;
 			break;
-		case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 17:
+		case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 7:
 			if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
 			    min(INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp))
 				continue;
 			break;
-		case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 17:
+		case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 7:
 			if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
 			    min(INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp))
 				continue;


                 reply	other threads:[~2022-11-14 10:58 UTC|newest]

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