From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f199.google.com (mail-oi1-f199.google.com [209.85.167.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CC44E4BB267 for ; Tue, 29 Sep 2026 22:04:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790719455; cv=none; b=VStLObTVoz7bQftBvlBZ1Q6ICeeP3zG4LWIqRBsPxGOeyIGmsGRKPYfjDsCpDvh+TtgbF1Jos1z6LcCSZSTvm33xlmzfd4tlYVPpbINiUFRGEZh102RwxGK3G37qq4Tesh1QA00Jki1gaFR12CJR3eXbl0YoR3awP9Rcv2IpoEE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790719455; c=relaxed/simple; bh=YxAlMmfVcm2W4cU7DakMAjMJLU1Lttxry7DoFyXpeys=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=XjQCCiAWfCt+uLKxHvIHYWLWq7YcfODClFdELqtqwYmkc56s9FkC6uriCFchGk0UeBrJL7Hr1SaSJCYqHgiIrvIQxx3FjUw52bCKehx6Gt6hW5JglpAsM+/iyjEzCcuo2uPlzhULEkwVcwx4CovFcFyueRuERICchMPLqaBbf3w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--coltonlewis.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=boaIMtN2; arc=none smtp.client-ip=209.85.167.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--coltonlewis.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="boaIMtN2" Received: by mail-oi1-f199.google.com with SMTP id 5614622812f47-4b26d8d2498so7475778b6e.2 for ; Tue, 29 Sep 2026 15:04:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1790719453; x=1791324253; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=1dGp94WLO2gdDysa7HIE4Qlt4fCj3et0VUDMOFJDyak=; b=boaIMtN2F6SKV2UXWEPsvgpSaMqoKNFG/ApU+MhZ+og2UKQrQP7mNh6kTpcpcIzVcS yNkgdsT6pe/Jf8/OfpIbSRozzY6/k0c2U/4TSTds7WBfIK1AivvQh9Bg38Z9Z56++j+k +pHOX8lPnIhBhF6kQo9i798bMg54JxcZqJ1Sftz0uxcLZhkKaD48VjvT9oa+MUS/cNLM pCGCXYP9bQ24ZNQni2pLLVVAZ0SuxFOa6Frnkp493wo6hcw1rjshn5sBnskxjTBnbaUi Z1/qsjSpufk6NvF9kAV+xeZDIwgx4rVTgvpfM3G7stq1mIl+YWgNKFEB6otNjTUuV7H0 b9Bg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790719453; x=1791324253; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=1dGp94WLO2gdDysa7HIE4Qlt4fCj3et0VUDMOFJDyak=; b=QRw17Bfjlq7bS5IdbdMvgXFylOT3rUecs8Ul8MX9UdXcbbgIBBk6pDVnL7kcHBarXh 5hjX/+XB8eXRifKoBZrBTxm31smvM4/NrQ33a+0XyPqb9IgABIvAvSSYgWwBy0kzSNaP n3eas7FZjSwx3pZVF+coAkQN0BFW5f4E0CMofLDxAf6KZg6rhY7Ca2SqOpY4eJ1v1d6N rqata5vHZGoV33ApIG8rDjl4uIDL9lgYIzKgfYiDjXLiCN/tzurhMkbYYPyUrZ1vzbIO yMvYrgImhF1zDPQ0fs5psk9Se0EIUDMfxw2rR+nw/Lu9SR2fGU5nM7XPzCdUeXQj1y5D d3HA== X-Forwarded-Encrypted: i=1; AKwUvBxw0UYqwclIjV3mDSydyNZ6H1yZEbIMC1NFBIdtkPNSOfq+gLOZIAe2in2XWIz88tnoyMnv11KUV9mnlEc=@vger.kernel.org X-Gm-Message-State: AFuF++k/K6d8CqpbL0AsV1/gIxrB4g/nOLmFgiPp0DTC3SmWCHDCRbmj +QSsQSkCc2lZ8ipTPXduj+V7dNp0A5k3zi399dChNt6oOF15mmnwReiabU0JeGzNsCWTlCZrlYk XANYA71EhKpSHlyt6aP9K/37z+Q== X-Received: from jabgg6.prod.google.com ([2002:a05:6638:6906:b0:5f6:798e:166d]) (user=coltonlewis job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6808:1927:b0:4ec:f57c:f81a with SMTP id 5614622812f47-4f074dcd517mr1045481b6e.12.1790719452327; Tue, 29 Sep 2026 15:04:12 -0700 (PDT) Date: Tue, 29 Sep 2026 22:04:11 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.56.0.rc1.315.gc6ed9934b7-goog Message-ID: <20260929220411.3756519-1-coltonlewis@google.com> Subject: [PATCH] KVM: arm64: Check ID_AA64DFR0_EL1.PMUVer in reset_pmevtyper() From: Colton Lewis To: kvmarm@lists.linux.dev Cc: Marc Zyngier , Oliver Upton , Fuad Tabba , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Colton Lewis Content-Type: text/plain; charset="UTF-8" When userspace initializes a vCPU with KVM_ARM_VCPU_PMU_V3 but sets ID_AA64DFR0_EL1.PMUVer to NI (0) or IMP_DEF (0xf, which is sanitized to NI), resetting the vCPU invokes reset_pmevtyper(). Because reset_pmevtyper() only checks kvm_vcpu_has_pmu(), it proceeds to call kvm_pmu_evtyper_mask(), which reads PMUVer == 0 from ID_AA64DFR0_EL1 and triggers a WARN_ONCE("Unknown PMU version 0") in __kvm_pmu_event_mask(). Check ID_AA64DFR0_EL1.PMUVer directly in reset_pmevtyper() via kvm_has_feat() instead of kvm_vcpu_has_pmu() so that PMEVTYPER_EL0 resets to 0 without querying the event mask when PMUv3 is not exposed to the guest. Fixes: bc512d6a9b92 ("KVM: arm64: Make PMEVTYPER_EL0.NSH RES0 if EL2 isn't advertised") Suggested-by: Oliver Upton Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Colton Lewis --- arch/arm64/kvm/sys_regs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index a2f4e769a4282..0bb3c2f10a22c 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1060,7 +1060,7 @@ static u64 reset_pmevcntr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) static u64 reset_pmevtyper(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { /* This thing will UNDEF, who cares about the reset value? */ - if (!kvm_vcpu_has_pmu(vcpu)) + if (!kvm_has_feat(vcpu->kvm, ID_AA64DFR0_EL1, PMUVer, IMP)) return 0; reset_unknown(vcpu, r); -- 2.56.0.rc1.315.gc6ed9934b7-goog