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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Jim Mattson <jmattson@google.com>, Marc Orr <marcorr@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Sasha Levin <sashal@kernel.org>,
	kvm@vger.kernel.org
Subject: [PATCH AUTOSEL 4.9 07/13] kvm: vmx: Limit guest PMCs to those supported on the host
Date: Wed,  9 Oct 2019 13:06:26 -0400	[thread overview]
Message-ID: <20191009170635.536-7-sashal@kernel.org> (raw)
In-Reply-To: <20191009170635.536-1-sashal@kernel.org>

From: Jim Mattson <jmattson@google.com>

[ Upstream commit e1fba49cc1e965a3dacd897367ba1e7b340cf0f4 ]

KVM can only virtualize as many PMCs as the host supports.

Limit the number of generic counters and fixed counters to the number
of corresponding counters supported on the host, rather than to
INTEL_PMC_MAX_GENERIC and INTEL_PMC_MAX_FIXED, respectively.

Note that INTEL_PMC_MAX_GENERIC is currently 32, which exceeds the 18
contiguous MSR indices reserved by Intel for event selectors. Since
the existing code relies on a contiguous range of MSR indices for
event selectors, it can't possibly work for more than 18 general
purpose counters.

Fixes: f5132b01386b5a ("KVM: Expose a version 2 architectural PMU to a guests")
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/kvm/pmu_intel.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/pmu_intel.c b/arch/x86/kvm/pmu_intel.c
index 2729131fe9bfc..170ca7eeb15b7 100644
--- a/arch/x86/kvm/pmu_intel.c
+++ b/arch/x86/kvm/pmu_intel.c
@@ -260,6 +260,7 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 {
 	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+	struct x86_pmu_capability x86_pmu;
 	struct kvm_cpuid_entry2 *entry;
 	union cpuid10_eax eax;
 	union cpuid10_edx edx;
@@ -281,8 +282,10 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	if (!pmu->version)
 		return;
 
+	perf_get_x86_pmu_capability(&x86_pmu);
+
 	pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters,
-					INTEL_PMC_MAX_GENERIC);
+					 x86_pmu.num_counters_gp);
 	pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1;
 	pmu->available_event_types = ~entry->ebx &
 					((1ull << eax.split.mask_length) - 1);
@@ -292,7 +295,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	} else {
 		pmu->nr_arch_fixed_counters =
 			min_t(int, edx.split.num_counters_fixed,
-				INTEL_PMC_MAX_FIXED);
+			      x86_pmu.num_counters_fixed);
 		pmu->counter_bitmask[KVM_PMC_FIXED] =
 			((u64)1 << edx.split.bit_width_fixed) - 1;
 	}
-- 
2.20.1


  parent reply	other threads:[~2019-10-09 17:25 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-09 17:06 [PATCH AUTOSEL 4.9 01/13] scsi: ufs: skip shutdown if hba is not powered Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 02/13] scsi: megaraid: disable device when probe failed after enabled device Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 03/13] scsi: qla2xxx: Fix unbound sleep in fcport delete path Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 04/13] ARM: OMAP2+: Fix missing reset done flag for am3 and am43 Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 05/13] ARM: dts: am4372: Set memory bandwidth limit for DISPC Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 06/13] MIPS: dts: ar9331: fix interrupt-controller size Sasha Levin
2019-10-09 17:06 ` Sasha Levin [this message]
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 08/13] nl80211: fix null pointer dereference Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 09/13] mac80211: fix txq " Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 10/13] mips: Loongson: Fix the link time qualifier of 'serial_exit()' Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 11/13] net: hisilicon: Fix usage of uninitialized variable in function mdio_sc_cfg_reg_write() Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 12/13] namespace: fix namespace.pl script to support relative paths Sasha Levin
2019-10-09 17:06 ` [PATCH AUTOSEL 4.9 13/13] Make filldir[64]() verify the directory entry filename is valid Sasha Levin

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