From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f200.google.com (mail-oi1-f200.google.com [209.85.167.200]) (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 3EA6951E42D for ; Wed, 30 Sep 2026 21:18:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790803118; cv=none; b=lXAd3I7vXtc7Fto1zPIDK1Ya3Vr9W0RCKSSrKvRjtt+H7H7d0Oujcm1uleV8pItH+c2Pr9KmrIMdPFySUTAjDXUGGRE4o8DEr2vXoD9JNlhTWf2lPjRhrogu4R4rphBsMBaof+ywtNmhh5KdSnm/8GW+VHpBYbjzCmUqPeNLRY8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790803118; c=relaxed/simple; bh=1zpGeqQhQHL87M4JhAi1mEkbl1rvBkOkkOhj9EwgPFM=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=eRKEbRJK23rm+h4H27e2RQPZB8byP91Ec1h39VlO1yRxF16GfJ6E7enqNZVOmtLZmkSexgVyx1S5U0XpZWvxGEPuZLEQhCjmzZGDXKJclk6u+SxyAAnKkyfqlymQGOkr7S1/81HddYox5NkeghVWmX90uEtmtn55SnesShS8EFI= 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=CrYxZnEf; arc=none smtp.client-ip=209.85.167.200 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="CrYxZnEf" Received: by mail-oi1-f200.google.com with SMTP id 5614622812f47-4b2d1eb484aso9108238b6e.2 for ; Wed, 30 Sep 2026 14:18:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1790803116; x=1791407916; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=IvNQ4tIxSouECNeVr4s6zto6hS9KDqxG0yViEXlduVY=; b=CrYxZnEfYm+l1P/2utU8zz+ySYiUCCdIPg6XDUIoF3RnpM8/DcBXFHaRW0uVC4uBkG AChKuUdwpS0+5cLAvu+hUuBHjnvU5QMh0CaOiSiaH6/UC8WQGiK+ZuBhj2yrE9kSbqDU TEzL4oAcd/ZSzs7HW0d4pjevM/r4VC4G1pYKM6agE63fzSVw/bQBUSXsWymXM8jWqu4Y kH3QP+DiSDM9BNpyc+4dx4CvNoVFLEXWd+Co7Ufv6RXP2ny8PHRJEawLTeMAoZeHf9yc OwXoBE6VP8G7QMACkDPOnLAQ1J/nBzBA5B9vxlXlpUGU7GzCKYALNxs/kp3ymVYfCZ1m +AwA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790803116; x=1791407916; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=IvNQ4tIxSouECNeVr4s6zto6hS9KDqxG0yViEXlduVY=; b=nZRmT04II9I/NYwuluALESgCbkx/Rbcro6jbcQpaY6k/Dv54sK3KBE7FqAQoeApEVy B9NaEalQSz0L/JEaMVJ/P43T00pTfcg560rDr35X7AeEi4FOfrUddWihz4PQtn9el++K zlk70m+O7x24t7R5rYXXNHzOhBECwdo/RJAGmRjRBHqRG0IarFwFpIwey59FtmkLmW98 xoYapxyDLSin/efXjN+mkAWrU1bl+PjERMmPM4DCUQf1mB7M3WSODlWhMZllJdPHq8mk vIvHBMaUhcG7qv9ihPBf1yQ2J1vByxQXU3oR+RSxb2Mk3YkqtnKjcpJXx3TeMZsmPJna UGoQ== X-Forwarded-Encrypted: i=1; AKwUvBz4v1P/4wk5zOtAkhbpjVwFWke7GxqKyUe5YsDX8jXS2fePlzu3/4fs0mva8mNaHgaz/H9uK4xqQX+4sE0=@vger.kernel.org X-Gm-Message-State: AFuF++nkQZGUvVdYb1RuAzxFLAUEGVZwjL1x8bxD7N15NfanBtUJSAty Qy7c4qn6dun5hEDdu+uaGbC4qhkmzG4kB5AnIA1u6KD5nbOluIwfErw/dPWSq51hxpk92Vfa59/ JxAXgL+E2Hat05iZ78y8F3M9AnA== X-Received: from iljm9.prod.google.com ([2002:a05:6e02:de9:b0:50d:b61e:e6c3]) (user=coltonlewis job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6808:1190:b0:4d6:9153:295e with SMTP id 5614622812f47-4f1ba4fc340mr2480554b6e.47.1790803115577; Wed, 30 Sep 2026 14:18:35 -0700 (PDT) Date: Wed, 30 Sep 2026 21:18:33 +0000 In-Reply-To: <20260930211834.2773546-1-coltonlewis@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260930211834.2773546-1-coltonlewis@google.com> X-Mailer: git-send-email 2.56.0.rc1.315.gc6ed9934b7-goog Message-ID: <20260930211834.2773546-2-coltonlewis@google.com> Subject: [PATCH v2 1/2] KVM: arm64: Handle ID_AA64DFR0_EL1.PMUVer == NI in __kvm_pmu_event_mask() From: Colton Lewis To: kvmarm@lists.linux.dev Cc: maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, pbonzini@redhat.com, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, linux-kernel@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() and calls kvm_pmu_evtyper_mask(). Because __kvm_pmu_event_mask() does not handle ID_AA64DFR0_EL1_PMUVer_NI, it triggers a WARN_ONCE("Unknown PMU version 0"). Explicitly handle ID_AA64DFR0_EL1_PMUVer_NI in __kvm_pmu_event_mask() by returning an event mask of 0, and drop the redundant kvm_vcpu_has_pmu() check in reset_pmevtyper(). Fixes: bc512d6a9b92 ("KVM: arm64: Make PMEVTYPER_EL0.NSH RES0 if EL2 isn't advertised") Suggested-by: Oliver Upton Assisted-by: LLM Signed-off-by: Colton Lewis --- arch/arm64/kvm/pmu-emul.c | 5 ++++- arch/arm64/kvm/sys_regs.c | 4 ---- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 5b1af7e2176fa..e2b28dbc0451b 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -50,8 +50,11 @@ static u32 __kvm_pmu_event_mask(unsigned int pmuver) case ID_AA64DFR0_EL1_PMUVer_V3P5: case ID_AA64DFR0_EL1_PMUVer_V3P7: return GENMASK(15, 0); - default: /* Shouldn't be here, just for sanity */ + default: + /* Shouldn't be here, just for sanity */ WARN_ONCE(1, "Unknown PMU version %d\n", pmuver); + fallthrough; + case ID_AA64DFR0_EL1_PMUVer_NI: return 0; } } diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index a2f4e769a4282..e4ad9c171c7ca 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1059,10 +1059,6 @@ 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)) - return 0; - reset_unknown(vcpu, r); __vcpu_rmw_sys_reg(vcpu, r->reg, &=, kvm_pmu_evtyper_mask(vcpu->kvm)); -- 2.56.0.rc1.315.gc6ed9934b7-goog