From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 349E81C84BB for ; Fri, 14 Nov 2025 12:40:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763124028; cv=none; b=n3Ec185G7nAv8+ia/tNlNRyeGkXLR6y4QrAvpG5vc5YnN8R/KDbvV8oELrXr6+Fh1dxlbaB0GnBHTDM2DAAYdLZtrRVdoGt6DuJ7A0MRTt7MsGfTPydKiznADI1UNAI/Wqgqk+OGYQTRgtSi+aSVACx1lxOiIwLSndMO1udHvaw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763124028; c=relaxed/simple; bh=1S7oMaiMrQhbrBE5JZaaD3PrCA7SNK04RmgkbjRg6zA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=E5lnwxdfexYLEu5sUbKbFBZBERuLfoUgd+PZAmI6jbitK3lLTTWRO6eJEFmPKpVICGMpbwkBCPj/VuAnu+nNjqX3A6BNA5Vgkk6U6f7sPWCBo9ouMbSdaQUcgb4kNEMH4sOhWQ0OjjtGUM6dnztlFuzyNO1cXNbkcwSHlQOjq9o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jackmanb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=VtN5a8Wk; arc=none smtp.client-ip=209.85.128.74 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--jackmanb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="VtN5a8Wk" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-4710d174c31so18987375e9.0 for ; Fri, 14 Nov 2025 04:40:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1763124026; x=1763728826; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=+mnkKCVTFBypK6JgR4pPkzvAmtwTh/tLRTgr+WHrD5Q=; b=VtN5a8WkpibviBOENU2EobEtxaW5KYk8vBneVGJPtHg695Otpx21pniKPZDdmL+ZDg 3BNC2SvJmC8hkO4EHelmBT6nofPnVjpiev7UBA3z10GPgU3/Hh2vIcXLg60bhomU4ZQz QcFX4kZCcJ1O5o2MSRQiKkSoRrFgCWrpCd7QSff70mgpO/W9b7xjTMJp2MxG6ec3jrgS hBarAr0mqWZDRMkD+H4PxEImuwjygmW052RyLGpPfyphuQd/pvUUu+40LQEb43PUIah+ DOtn7yTehM47JarTi+7L34sWIelHeTB3elHRxcmc4BfQA22+mE2vyZALSxHyRWhe6iwE /Mcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763124026; x=1763728826; h=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=+mnkKCVTFBypK6JgR4pPkzvAmtwTh/tLRTgr+WHrD5Q=; b=xJov5+I0PrFHn/c3AdqvjMKb9v+xLDqGRFh1jfiS6N6b2NhF7GJoaDTjgjjSBovElJ rC/RAjsz8oMM082f1NQHVHBdBFH65aHH6aCCjfj5n5YC2MvqumGJu6h7JYxWU0YYKp/D YuDXbAItdg9+SXw3+tQpFAgTkS/U7+/7iRuZ3I3kmemBpVXA03JI4DFjQIOsjhPRCq2G p8ZD9zBKpb7Ut1fAWnaMH+D2zNi+mIsfrvnq/Ai2+oOD/WS6WG1V5ZK9ccaB190T4fin lFJ4P/oEOcqNHv91yDv88ch8Pyx10sxB3g5yLkXf6dMF4W8OytIUBXEHAwH4we9YNWuG BZeg== X-Gm-Message-State: AOJu0YzqfLlDNNlYcXZWs8F+o2SqId9rZZbtDKfpJxV/igNpL7vwuP22 H3Q4eygWJjKB/yfLSadFj7xzRGVqBHEL9uKrSe4n5VkWRBDomThmLUNvvzfOclMqoMrE9cbT4Ik whozUscy5/XsbzQ== X-Google-Smtp-Source: AGHT+IE3n1k80MuyIwex32RymBBJ3wkzNS9chxunz1u2NCAGwFePOCUhGXCOZClPfDc3vS+fOvbMrhUciWJf9Q== X-Received: from wmlu9.prod.google.com ([2002:a05:600c:2109:b0:477:3fdf:4c24]) (user=jackmanb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:4f93:b0:477:5c58:3d42 with SMTP id 5b1f17b1804b1-4778fe588a9mr27893345e9.10.1763124025773; Fri, 14 Nov 2025 04:40:25 -0800 (PST) Date: Fri, 14 Nov 2025 12:40:25 +0000 In-Reply-To: <20251113233746.1703361-3-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20251113233746.1703361-1-seanjc@google.com> <20251113233746.1703361-3-seanjc@google.com> X-Mailer: aerc 0.21.0 Message-ID: Subject: Re: [PATCH v5 2/9] x86/bugs: Use VM_CLEAR_CPU_BUFFERS in VMX as well From: Brendan Jackman To: Sean Christopherson , Paolo Bonzini , Thomas Gleixner , Borislav Petkov , Peter Zijlstra , Josh Poimboeuf Cc: , , Pawan Gupta , Brendan Jackman Content-Type: text/plain; charset="UTF-8" On Thu Nov 13, 2025 at 11:37 PM UTC, Sean Christopherson wrote: > From: Pawan Gupta > > TSA mitigation: > > d8010d4ba43e ("x86/bugs: Add a Transient Scheduler Attacks mitigation") > > introduced VM_CLEAR_CPU_BUFFERS for guests on AMD CPUs. Currently on Intel > CLEAR_CPU_BUFFERS is being used for guests which has a much broader scope > (kernel->user also). > > Make mitigations on Intel consistent with TSA. This would help handling the > guest-only mitigations better in future. > > Signed-off-by: Pawan Gupta > [sean: make CLEAR_CPU_BUF_VM mutually exclusive with the MMIO mitigation] > Acked-by: Borislav Petkov (AMD) > Signed-off-by: Sean Christopherson Reviewed-by: Brendan Jackman