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 1EA4A51E451 for ; Wed, 30 Sep 2026 21:18:38 +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=1790803119; cv=none; b=kRNH7I4ozkpGxMpmSGC5IPaId80WYwjvwNvruASImDXGoXbMbQSH4lBLUKJvcn2AqjkumuGVat0V3L8bCu5vVa6NQ+kjjYR6elFN7lF2Y9MFq3ADLZXhBEnBnGlCM7rXfTqt5IR5c3jbTMZkuYpWSbhJk0pO5UVo1cNK4Y1p3zk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790803119; c=relaxed/simple; bh=D4RW4eqr7X/vrgI4ObQ8n39ajzCRfOk16wd5+OQqtL0=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=g8nYIl+a80xVFWZua+YLXGpJNBcKqv+K7Ok/Vtd7WbEQpNm99ad/YdnzYgYAoVgIcynzap0HZqN9+KUEmWdPzAwyqK2JsjwJFoACvmFvIK4xktVS3Nege/zTT1blEFOuXy5VMk7qmoEjorbGgPU1327YiA7NweB7dBwEJ7koUIs= 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=IkILSlu8; 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="IkILSlu8" Received: by mail-oi1-f200.google.com with SMTP id 5614622812f47-4b1bc2e44e0so8989177b6e.0 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=1790803117; x=1791407917; 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=o3da3ndZkq5JxsBN5E/e/pVYoGrUCtX487+oH/FKdMc=; b=IkILSlu8YyhvoTbVxfCrq7DGhnU0kBgDYRKCZwRt+j7NavDgr7K67TsB2Si0q5vvaK bgmHyrzbRe+fDJ7OF6sQieHYNxTPavk0RqJdb093yRwic7sr0CdMGplJ2OoI4ieWiRMA kc3Cvf70+iOVXJ5Yz2r0su7367fbZ4wQaz2Dg1dHi7rI/Vdq04inwttpykb7IO2dZRwz IJjG2+JkXUxTcxSZurFPnEdC8t4xF/I2ceKTllMPuVPz1JBS7jJMCD+4Bw7YI8FGjRm3 lzk5OMheny3RVctusW6szzGYuVgoA4ewahUFYAjoizRyKwUeVTRDnpF4Z4wh+SIfzwW7 dbTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790803117; x=1791407917; 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=o3da3ndZkq5JxsBN5E/e/pVYoGrUCtX487+oH/FKdMc=; b=Lm1mcPrK7ENF+LM9EfTzIVT91kj5ObjNyQLQgJNAbBqGqNaVm8OxdkOHhreaeIiITI FylJ0gEBkPZPNfpiuLmwA5ooeWt0uriCKJKrVnj2wzETPAVzGpJzVtW3seSuAhhNkSy0 gI5DQ9Mvv5Wqp0Xbjiu1qeh9EesGFjJiYsm9Ha8RcGcpFHoSoI6WjYyjaGrAnnd+rf+R EBNaNYgg19u9AHNi2BAeTK89KRNMQTKUyC6mWOWgExXQiV548ruWBWzaj4ucIQuaUGs4 lCBWdea6HfBuo0WWDPdwZnVfLg+6oYnf8zTVmXfuJs8mtkZDda7y25yTGTIi7vcB1lYh 9Liw== X-Forwarded-Encrypted: i=1; AKwUvBz5wawPNgFxgfjaYif3ZYWA7rAr4RfFnuWVhktiU9MfGNSwHsi7FDfyuhFwVbmP7+Bsvew=@vger.kernel.org X-Gm-Message-State: AFuF++nYOUKA9BpvMgDusPJ9IvVf3RcSc+KSYQu3WFz++Ek6k6oEPki/ /bvNamNs2CgfghEJybCzTGy4oRkNPh0pZdkpkJGIknwFRgB30sDqYc9NsPY5aYzNg984D2XaqGx 6sVbdoJNZ3t9N/DCLgQKMVfK/LQ== X-Received: from iobir24.prod.google.com ([2002:a05:6602:7158:b0:9c3:8b15:2c82]) (user=coltonlewis job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6808:138b:b0:4e8:d530:daf6 with SMTP id 5614622812f47-4f1b6c6e13fmr3792236b6e.26.1790803116491; Wed, 30 Sep 2026 14:18:36 -0700 (PDT) Date: Wed, 30 Sep 2026 21:18:34 +0000 In-Reply-To: <20260930211834.2773546-1-coltonlewis@google.com> Precedence: bulk X-Mailing-List: kvm@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: <20260930211834.2773546-3-coltonlewis@google.com> Subject: [PATCH v2 2/2] KVM: arm64: Check ID_AA64DFR0_EL1.PMUVer in pmu_visibility() 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" pmu_visibility() currently checks kvm_vcpu_has_pmu(), which only tests whether the vCPU was initialized with KVM_ARM_VCPU_PMU_V3. If userspace initializes a vCPU with KVM_ARM_VCPU_PMU_V3 and subsequently hides FEAT_PMUv3 via ID_AA64DFR0_EL1.PMUVer, KVM continues to expose the PMU system registers instead of emulating guest accesses as UNDEF. Check ID_AA64DFR0_EL1.PMUVer directly via kvm_has_feat() in pmu_visibility() so that PMU system registers are marked REG_HIDDEN whenever FEAT_PMUv3 is not advertised in the ID registers. Suggested-by: Oliver Upton 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 e4ad9c171c7ca..46dd6e16de28e 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1029,7 +1029,7 @@ static unsigned int hidden_visibility(const struct kvm_vcpu *vcpu, static unsigned int pmu_visibility(const struct kvm_vcpu *vcpu, const struct sys_reg_desc *r) { - if (kvm_vcpu_has_pmu(vcpu)) + if (kvm_has_feat(vcpu->kvm, ID_AA64DFR0_EL1, PMUVer, IMP)) return 0; return REG_HIDDEN; -- 2.56.0.rc1.315.gc6ed9934b7-goog