From a80c4ec10ed9632c44c829452dc40a0443ff4e85 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 8 May 2019 19:02:48 +0200 Subject: [PATCH] x86/kvm/pmu: Set AMD's virt PMU version to 1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit After commit: 672ff6cff80c ("KVM: x86: Raise #GP when guest vCPU do not support PMU") my AMD guests started #GPing like this: general protection fault: 0000 [#1] PREEMPT SMP CPU: 1 PID: 4355 Comm: bash Not tainted 5.1.0-rc6+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:x86_perf_event_update+0x3b/0xa0 with Code: pointing to RDPMC. It is RDPMC because the guest has the hardware watchdog CONFIG_HARDLOCKUP_DETECTOR_PERF enabled which uses perf. Instrumenting kvm_pmu_rdpmc() some, showed that it fails due to: if (!pmu->version) return 1; which the above commit added. Since AMD's PMU leaves the version at 0, that causes the #GP injection into the guest. Set pmu->version arbitrarily to 1 and move it above the non-applicable struct kvm_pmu members. Signed-off-by: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Janakarajan Natarajan Cc: kvm@vger.kernel.org Cc: Liran Alon Cc: Mihai Carabas Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: "Radim Krčmář" Cc: Thomas Gleixner Cc: Tom Lendacky Cc: x86@kernel.org Cc: stable@vger.kernel.org Fixes: 672ff6cff80c ("KVM: x86: Raise #GP when guest vCPU do not support PMU") Signed-off-by: Paolo Bonzini --- arch/x86/kvm/pmu_amd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/pmu_amd.c b/arch/x86/kvm/pmu_amd.c index 1495a735b38e7..50fa9450fcf11 100644 --- a/arch/x86/kvm/pmu_amd.c +++ b/arch/x86/kvm/pmu_amd.c @@ -269,10 +269,10 @@ static void amd_pmu_refresh(struct kvm_vcpu *vcpu) pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1; pmu->reserved_bits = 0xffffffff00200000ull; + pmu->version = 1; /* not applicable to AMD; but clean them to prevent any fall out */ pmu->counter_bitmask[KVM_PMC_FIXED] = 0; pmu->nr_arch_fixed_counters = 0; - pmu->version = 0; pmu->global_status = 0; } -- 2.39.5