From 2e8cd7a3b82874e9cb3e42d916dda05cd790cc1a Mon Sep 17 00:00:00 2001 From: Like Xu Date: Wed, 24 Jun 2020 09:59:28 +0800 Subject: [PATCH] kvm: x86: limit the maximum number of vPMU fixed counters to 3 Some new Intel platforms (such as TGL) already have the fourth fixed counter TOPDOWN.SLOTS, but it has not been fully enabled on KVM and the host. Therefore, we limit edx.split.num_counters_fixed to 3, so that it does not break the kvm-unit-tests PMU test case and bad-handled userspace. Signed-off-by: Like Xu Message-Id: <20200624015928.118614-1-like.xu@linux.intel.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/pmu.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 5bec182aa648..6f2b6e9c9ae0 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -606,7 +606,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) eax.split.bit_width = cap.bit_width_gp; eax.split.mask_length = cap.events_mask_len; - edx.split.num_counters_fixed = cap.num_counters_fixed; + edx.split.num_counters_fixed = min(cap.num_counters_fixed, MAX_FIXED_COUNTERS); edx.split.bit_width_fixed = cap.bit_width_fixed; edx.split.reserved = 0; diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h index ab85eed8a6cc..067fef51760c 100644 --- a/arch/x86/kvm/pmu.h +++ b/arch/x86/kvm/pmu.h @@ -15,6 +15,8 @@ #define VMWARE_BACKDOOR_PMC_REAL_TIME 0x10001 #define VMWARE_BACKDOOR_PMC_APPARENT_TIME 0x10002 +#define MAX_FIXED_COUNTERS 3 + struct kvm_event_hw_type_mapping { u8 eventsel; u8 unit_mask;