From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 4ECC412E1E9 for ; Mon, 13 Oct 2025 23:30:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760398245; cv=none; b=A81iMAvk9EO3ex37ABZ/BNscISrlRCmRDh7HGpBbbUBnjcN3noKO66n10kGZawcDkxq/FalabBqMMInciu+rwcIZ1B6Hc+dbAAA57UNxvs2a5N7UU80NicUiy6NDdX0DCxFvYnQJUehGON4tgKmnMOGsF1X7Pub79dDwheImW9E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760398245; c=relaxed/simple; bh=f1t956JBV+YwJMh+YwrrZfOciYvg7blVAnIMvPKNYWY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=C6k8655Vs6VHNTsdzSwYQRAggJmD1z8D/WpVTLaLRAFF2g6oreNsUkUTZtTBQvopYaeqzmwlG9e3JocX1BwdNgUFJScHN8VJM0yfogDvEBAzkcyY7tDJjVT4b7DjbgW6Cqm/5u3RFKqNoL9DzNFi7fhs+Xq22mVrukRQJ5xxZS4= 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=mrfvr61U; arc=none smtp.client-ip=209.85.216.73 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="mrfvr61U" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-33428befb83so11771885a91.1 for ; Mon, 13 Oct 2025 16:30:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1760398244; x=1761003044; 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=08aB01K3QlDxNQ6Di+ZC0Fy9ecw0hHQXKJJoqFOXoow=; b=mrfvr61Ugf4rpjGO8UXGuha8lRWdgkY/sLtMnr78KwaMUOdM6uKKzGfzesQl8+iPBq EtQHDsofTHP1JyBmqv6alF/edo4ODjyB9lipAMXSINBvUKBEZ+h6jgfNyF4my5fladVC quiE6ipsSnyfeEDyqPqTsGpkmvZg2wRpLtPy6hX9GPyK/2hrA128SeddJ0o5ER28d1VU CnjIwzyhCVd2aX32rcwjdLqZ7ah8e5pCR6WT/0LApLOAQj0DICy1mwXoYq+lTDR0Qd7Z JYX+ewFLTz/Mp4YF+8gU5EB9nFVWrMkzdt1/Ov+rTgjxnb7u1lEtcW08LGSdEM/dD8wZ B6Xg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760398244; x=1761003044; 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=08aB01K3QlDxNQ6Di+ZC0Fy9ecw0hHQXKJJoqFOXoow=; b=k7LdqBQbeNAg4D1BeARm907YYZj+oeiq98eiWa1dZaBPQ193Z+r2DtvqnDReeVS6eC Hc0g9Vex2qO/VpiCpwliFhAZ8V0+0KviEhcuw3dXIfQMO91/dRd0tt+xsu6kvJ1/7yKb 24qyaanQ930iTx8DqOklMjABNAEHo7OUKX1Het+RuKOa2HRbGxqYXuwzHkI0oDDwvx/l y2F2ISelj1TkGj7ECkS4DyKBWsvWYVwsd+mPhfnO3p3Hu3RFUID+eOSZkx8t0iXUycUA 0vB+agnUp9J2VNMCyZe3Fc7Pg3z+BqcUE5QxLTHI0cnNqTaAaoytXeh9nvBSYbQwaopV jaMQ== X-Forwarded-Encrypted: i=1; AJvYcCXLjTunihBpY5KnWgRBB5Ftjo9036AfGc8nQkZsB5qGcZO/etHXz+7iQH3ORfKtKDYbFb4=@vger.kernel.org X-Gm-Message-State: AOJu0YwxcrVh7QZ4W+iMZ+p/T9zdiKA8nJVRzL0YJ+bws/c/7qmNh0vi eVrAFG6Kkra56VRB7QkgQYQxEKoHhMhc+ccCw9P3llV5Ns7hPsAquH5G2rGPEGRhPJfMqiGHRQn aww926w== X-Google-Smtp-Source: AGHT+IHs68Jiesyq8CVwopkosF1NFYrZ8tVJ5yK1fRCuny9H+M0GlqQ+GEI/HXfswBxaNk8YEghSh7Wv9pM= X-Received: from pjbgl20.prod.google.com ([2002:a17:90b:1214:b0:330:acc9:302c]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:1a87:b0:339:f09b:d36f with SMTP id 98e67ed59e1d1-33b513a1e0fmr28253894a91.28.1760398243550; Mon, 13 Oct 2025 16:30:43 -0700 (PDT) Date: Mon, 13 Oct 2025 16:30:42 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250922162935.621409-1-jmattson@google.com> Message-ID: Subject: Re: [PATCH 0/2] KVM: SVM: Aggressively clear vmcb02 clean bits From: Sean Christopherson To: Jim Mattson Cc: Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable On Mon, Oct 13, 2025, Jim Mattson wrote: > On Mon, Oct 13, 2025 at 2:54=E2=80=AFPM Sean Christopherson wrote: > > > > On Mon, Sep 22, 2025, Jim Mattson wrote: > > > It is unlikely that L1 will toggle the MSR intercept bit in vmcb02, > > > or that L1 will change its own IA32_PAT MSR. However, if it does, > > > the affected fields in vmcb02 should not be marked clean. > > > > > > An alternative approach would be to implement a set of mutators for > > > vmcb02 fields, and to clear the associated clean bit whenever a field > > > is modified. > > > > Any reason not to tag these for stable@? I can't think of any meaningf= ul > > downsides, so erring on the side of caution seems prudent. >=20 > SGTM. Do you want a new version? Good gravy, no. :-)