From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 A75DB31355C for ; Wed, 5 Nov 2025 19:44:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762371871; cv=none; b=BE2omkx5o25sHzklUC44bvryQWySEIDPZ7P6xN8oQft28itZGTSIu+OWHrvQ6QLUpw+kEisCGA5Gvr6jv+2QZKFG1ZERuiknlTYNwpokWkXpFuy6tJibNtZz6ao6kB0aGfKThQUFY2bI4MHOJN0TkX9UZCY0CP+U0qy3l9jJWRU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762371871; c=relaxed/simple; bh=F1PLsq9xm+III7HBdcj18czd5KsIWEZ81RMxhvzVsNg=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=c0zTmy7QX/5RltjNd4uHwkaMHxx7kSeeB8fY9roqlTlF94VR9Aa3E9NYGmj45VCiHHeIJ9H5dg+k4TscWXtlBknPkRhSqy3Ua3ajj+ZCKaAoZd7vOsgs+slm+7k41v376aLX4ETGAkGPw1vbSc8NudqzntSq0ZpjrVdA1R0h2Z0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=HAKZpPRO; arc=none smtp.client-ip=209.85.216.74 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--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="HAKZpPRO" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-341661973daso237889a91.3 for ; Wed, 05 Nov 2025 11:44:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1762371869; x=1762976669; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:from:to:cc:subject:date:message-id :reply-to; bh=K8ZK0MiZ1hzn7iH0lOR2KZ5CJE/Z492UpE0NsitI4ac=; b=HAKZpPROeyWEmoNXYbZCWAf/QHh47RVnABxelKbu8ysPRNzzl7e7qGLAzW7PvS6n5K 7eB3jqr9d+P1H4BV37W/lh2s3kPha1D7Jw8REzCfe+h/9Ugg9CL6sxOE2joLKlwiX5uy XQQr8oCzvnWf0P58S3yGP9dCyd+SiQTvz/g67TyAuvgNub0meEUM6CJocvYxTHPmYySF 7eyya8TlVN6nWjFNP7bdLx9FodfmquHascYSE0DkgLHfas+1VRh3TK6UzbFRbGDH394R +lpMUllEBKR1/uSUGJ/cqCkP2gdLv9KRUVYMtd6i4Y88bB77h0fwMcHnf5aptZxUM/8G iNcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1762371869; x=1762976669; h=content-transfer-encoding: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; bh=K8ZK0MiZ1hzn7iH0lOR2KZ5CJE/Z492UpE0NsitI4ac=; b=jVSQlNAq4/cUkarrzGs7KxGgC9rlLTxB77J2ozxOHL6xYTH5hUdPpsVmXVALZPAlnN u+Voz3e1DKJfuNkBll//h3Zfzf4SwEEFg1pbhQA+/Sr+DFmOBp5mj5KuZYg0bU1Rgq5Z ve6TitUa0+m8Ko+Jp3a9F/M8sXZ9PA6cTEAj8XhZabaZvgi9pCetqc+56W1ctqF4AzHi EV3d0FjXNsE9awU/188etiiEQwQgDF6cMWzHyzWYKWe7UQ2pn+RfY88egAH4Be6I/GnK Y3vuTAGCBLCfRcH5qXfPmAbGDF1Sz1d7OfDdiL+w5g01d01Rlj/6cAsjKl/ay+8ayHnr a6Eg== X-Forwarded-Encrypted: i=1; AJvYcCUmJqXwvGGXrb7mGdF+Edx8ajdpimMmmAucA6+WEBp2a+u5dKdOVsWiGkOPOEy7cpqDZCiJqgoo2zNueBM=@vger.kernel.org X-Gm-Message-State: AOJu0YwcD2SjFAHCsupHKRU8N5p+xlIs3yVZ+qJh92Faff4s2Psh/Dxy +pOdAwQfNPi3gVC4zGsXY7NjKio2UbAKzguES2hw35uViKUOVFnM74tLsIUhkAgmfcHd5sR1+Ki jhPUVuw== X-Google-Smtp-Source: AGHT+IGUe19WzjgS7NVl1on3cCWT7NzacMbeJ7zc1z1lSJo6Mtsb4w1JefM4Y086HcyZXcE3ju6dHq1EPBY= X-Received: from pjbca19.prod.google.com ([2002:a17:90a:f313:b0:340:66e4:4269]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:2dc3:b0:340:f05a:3ebd with SMTP id 98e67ed59e1d1-341a6dd9a30mr4900591a91.28.1762371868572; Wed, 05 Nov 2025 11:44:28 -0800 (PST) Date: Wed, 5 Nov 2025 11:44:27 -0800 In-Reply-To: <20251024192918.3191141-3-yosry.ahmed@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251024192918.3191141-1-yosry.ahmed@linux.dev> <20251024192918.3191141-3-yosry.ahmed@linux.dev> Message-ID: Subject: Re: [PATCH 2/3] KVM: nSVM: Propagate SVM_EXIT_CR0_SEL_WRITE correctly for LMSW emulation From: Sean Christopherson To: Yosry Ahmed Cc: Paolo Bonzini , Jim Mattson , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel, Matteo Rizzo Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Fri, Oct 24, 2025, Yosry Ahmed wrote: > When emulating L2 instructions, svm_check_intercept() checks whether a > write to CR0 should trigger a synthesized #VMEXIT with > SVM_EXIT_CR0_SEL_WRITE. For MOV-to-CR0, SVM_EXIT_CR0_SEL_WRITE is only > triggered if any bit other than CR0.MP and CR0.TS is updated. However, > according to the APM (24593=E2=80=94Rev. 3.42=E2=80=94March 2024, Table = 15-7): >=20 > The LMSW instruction treats the selective CR0-write > intercept as a non-selective intercept (i.e., it intercepts > regardless of the value being written). >=20 > Skip checking the changed bits for x86_intercept_lmsw and always inject > SVM_EXIT_CR0_SEL_WRITE. >=20 > Fixes: cfec82cb7d31 ("KVM: SVM: Add intercept check for emulated cr acces= ses") > Cc: stable@vger.kernel Bad email (mostly in case you're using a macro for this; the next patch has= the same typo).