From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EF325228C8D; Tue, 10 Dec 2024 20:41:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.151 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733863275; cv=none; b=R0hceW9/hwKkJxxWpMfFg4OqgG73Gqq5DZFT+xNLcfBphFBTb/mcdrYWdRUdprajFnzN3Fk245iJCZadxB75nfh7W5VL01YWFQPnlPzcev7Qj7fHGAALU9l3issHWaLDwQ1Ns1on3Cu7IYs22iHW3NPSHP4rQHkszbC+PNc99LI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733863275; c=relaxed/simple; bh=WzlgaaqUhE+WLmXr70jjwrg28mgcgmJ7MrB6fom+u8o=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=P6kIyqWvlGM0AgOZtG+LnKD8vP3Mtm6YGT5hLtpAfDNsaGkETovAD9sO7cIVYJwkcHtpr5TAh8nzPQZ4+ibXhdQ6KipE74JQLz+R0C5UkeKPE+9FQsSjqLw+UHcQZujg0I1962oRaElZNYI8eZA3dH2pWEjfE8wuztw9PAcGM8I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=RJI/Znfz; arc=none smtp.client-ip=80.241.56.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="RJI/Znfz" Received: from smtp202.mailbox.org (smtp202.mailbox.org [10.196.197.202]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4Y79S75H7nz9sRf; Tue, 10 Dec 2024 21:33:59 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1733862839; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vIkYPi7cZvR+Cq3i7sOkgKR+4usrBNWR28vWv5aHXPw=; b=RJI/Znfz/PYtHY+3VxJ/HMSqnJ36wtzAvyDFB2T1rYIKsE14oDoiHeQua55B8kNP6ZheUY 0ObNWeC4U2A5i4QdoVfzwZYn0mfHVgjjOntfEElSRMUohdc7Csa8k1A8QsWQ05KpL1jOVL AfTJA9faF8XrAQntuCqQ+mZDOhKnfxuNZbNZXbM+9yPkcmeL6huHFXTcx9LJQc7wJB9Cy8 5j9iUr+RUyrAdkSFjiwqaHdpbUnMNasW3B01PSyflsAH0uuPYabUhe1MPKccargZsMXRVH IowlDdhnI3MUfjux/dcgNCo7h9i6n8HzX3kNSXI2PwxhiMhpipJ3vYbZQPhj0A== Message-ID: <93a3edef-dde6-4ef6-ae40-39990040a497@mailbox.org> Date: Tue, 10 Dec 2024 21:33:58 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [REGRESSION] from 74a0e79df68a8042fb84fd7207e57b70722cf825: VFIO PCI passthrough no longer works To: Sean Christopherson Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, regressions@lists.linux.dev, Tom Lendacky References: <52914da7-a97b-45ad-86a0-affdf8266c61@mailbox.org> Content-Language: en-GB From: Simon Pilkington In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-MBO-RS-ID: 0cea7763452cf96db1b X-MBO-RS-META: hqxa4gxhzzjmcxgkgeomtyp99m94k69s On 10/12/2024 16:47, Sean Christopherson wrote: > Can you run with the below to see what bits the guest is trying to set (or clear)? > We could get the same info via tracepoints, but this will likely be faster/easier. > > --- > arch/x86/kvm/svm/svm.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c > index dd15cc635655..5144d0283c9d 100644 > --- a/arch/x86/kvm/svm/svm.c > +++ b/arch/x86/kvm/svm/svm.c > @@ -3195,11 +3195,14 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) > case MSR_AMD64_DE_CFG: { > u64 supported_de_cfg; > > - if (svm_get_feature_msr(ecx, &supported_de_cfg)) > + if (WARN_ON_ONCE(svm_get_feature_msr(ecx, &supported_de_cfg))) > return 1; > > - if (data & ~supported_de_cfg) > + if (data & ~supported_de_cfg) { > + pr_warn("DE_CFG supported = %llx, WRMSR = %llx\n", > + supported_de_cfg, data); > return 1; > + } > > /* > * Don't let the guest change the host-programmed value. The > @@ -3207,8 +3210,11 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) > * are completely unknown to KVM, and the one bit known to KVM > * is simply a reflection of hardware capabilities. > */ > - if (!msr->host_initiated && data != svm->msr_decfg) > + if (!msr->host_initiated && data != svm->msr_decfg) { > + pr_warn("DE_CFG current = %llx, WRMSR = %llx\n", > + svm->msr_decfg, data); > return 1; > + } > > svm->msr_decfg = data; > break; > > base-commit: fac04efc5c793dccbd07e2d59af9f90b7fc0dca4 Relevant dmesg output with some context below. VM locked up as expected. [ 85.834971] vfio-pci 0000:0c:00.0: resetting [ 85.937573] vfio-pci 0000:0c:00.0: reset done [ 86.494210] vfio-pci 0000:0c:00.0: resetting [ 86.494264] vfio-pci 0000:0c:00.1: resetting [ 86.761442] vfio-pci 0000:0c:00.0: reset done [ 86.761480] vfio-pci 0000:0c:00.1: reset done [ 86.762392] vfio-pci 0000:0c:00.0: resetting [ 86.865462] vfio-pci 0000:0c:00.0: reset done [ 86.977360] virbr0: port 1(vnet1) entered learning state [ 88.993052] virbr0: port 1(vnet1) entered forwarding state [ 88.993057] virbr0: topology change detected, propagating [ 103.459114] kvm_amd: DE_CFG current = 0, WRMSR = 2 [ 161.442032] virbr0: port 1(vnet1) entered disabled state // VM shut down