From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D713BE77188 for ; Mon, 6 Jan 2025 13:10:51 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 71B7A6B008A; Mon, 6 Jan 2025 08:10:51 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6CD266B0093; Mon, 6 Jan 2025 08:10:51 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5937B6B0095; Mon, 6 Jan 2025 08:10:51 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 3A6446B008A for ; Mon, 6 Jan 2025 08:10:51 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id DEAB8B0C1A for ; Mon, 6 Jan 2025 13:10:50 +0000 (UTC) X-FDA: 82977061860.22.4E54D70 Received: from mail-ed1-f48.google.com (mail-ed1-f48.google.com [209.85.208.48]) by imf02.hostedemail.com (Postfix) with ESMTP id E3DBB8000A for ; Mon, 6 Jan 2025 13:10:48 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=csAtVWgu; spf=pass (imf02.hostedemail.com: domain of jannh@google.com designates 209.85.208.48 as permitted sender) smtp.mailfrom=jannh@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1736169049; h=from:from:sender: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:dkim-signature; bh=Y2/skVBTqhd4oLklzEFskLFMUMvllpIbud1I2WS39gc=; b=mRgdLV2nqzSgLK5oSQ4w1xWTIZnOA9D3irXUjJ1GyvLCwoxZt6mijC2OpoqByz3NTvcQz3 8sMA2g8Pk8ePo3fKnK3gm4LZQzNSH125sbEyHJyjtdQITzDP8fr5c6d3Gd9ZrQ0t+pi91y OTjrWT8KhBPsV2QG99nWuLE1oMhsp9E= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=csAtVWgu; spf=pass (imf02.hostedemail.com: domain of jannh@google.com designates 209.85.208.48 as permitted sender) smtp.mailfrom=jannh@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1736169049; a=rsa-sha256; cv=none; b=xN3zADeIMleAiPfY94nDPm6xE1UTQI0rLuCuHhtMLMCrZ9VU2My6jxoed0WnNlPokdiqbh G30WR+VYbvC77+BVhX1Th0cQM30bNv+2hc/7+kfp8iFLhtEs2nzTx3JtGNBBKa7sgl+QNq JCZEWKtYAoaX6NR6f3ZuJAUqpRainOs= Received: by mail-ed1-f48.google.com with SMTP id 4fb4d7f45d1cf-5d3e638e1b4so9371a12.1 for ; Mon, 06 Jan 2025 05:10:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1736169047; x=1736773847; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Y2/skVBTqhd4oLklzEFskLFMUMvllpIbud1I2WS39gc=; b=csAtVWguMfy9ctF2W4Jq4kSC8RoDPfpsm87dAAPLrGDmC90opIwYeLooRczydUd3lW 4vbxBp9IjUeceKy5KMmbKlH4jr+a39GnzVrn7Ho+wJBJgNWRid3D2lk4xCP8qjjU8C4o ub9fAH+0XcrqQ+USvu0ITNuT1eToB7OUEZvuVPzG0W6DgvFj0Ec3wz1QwkZ1l62U31oS VTZT7W8tUOXbZ888a+TC0HrU36d1eLjxceExxgMun1QDxiQS+WmQaOE6eyA37wFScMdz VVgn4A5RReCSndekxUlfV1NnLbo0kTDjeLtI9kL5oFs168xxWqQ0Uj7lVHxSAXF9O7J4 nV6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736169047; x=1736773847; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Y2/skVBTqhd4oLklzEFskLFMUMvllpIbud1I2WS39gc=; b=ruavJsgdlQOB1PYzuUp4qFjPKtyidUPI1zeyt35vbqFZFHlylbe57goig9W3yolV/o rvyd10uIc/44E0NHfvbUyDWrttoK7VnSLH/Bv+F3FhYxyeuHp+s0EJfeF5jtmDVzGkfe 1RAgEt0C1zwfEjQve3k2QeVj36RVax23KlarS6PEqJJmE4q02n+Ag9jzJyal2nIWH1R5 irpVsayU0jLHaJ7eFChyItIWjPtgLwusmpZZzZdPM1cfcTVusqVMxD5OOQoa8VX1baUy G7UcG5FYhaY7QIS6Nsdtfnq1LzuaXAhyYmIaciEtPA84twKrOYAJON7PUWwCOSt0wczS M5pg== X-Forwarded-Encrypted: i=1; AJvYcCUNe2RNgUv98iYQFSm9cYiv0FHbflB9d90RzwKJT7S1ONmsxxfhP23PCYwUFG2Sg3RsZVjD07L0iA==@kvack.org X-Gm-Message-State: AOJu0YxJlTTSNqFCkUD9CHzWLuBSQcU1n+XfZgqn1mWcDeNEbVS6I/VK u78QXVXcJYpu2duaEJdPUBZWK6fX/DXtAghxFy+XlEw/QdAxTfm+XKK36Hn6ispDNB4cZpqaqng omF7yLpcF+2nxADpkoBKMZckrGCMlDVxMpFIG X-Gm-Gg: ASbGnct2JFmbZDTw9ypKho3K1fcWJaUzoVCYZLVDz5Y287oMKGjpuEHxkQ0Sw4t4UW4 ZZYZugxNs8VBC7iYT3qEg1XsRpS8OpXziB0k9zdQciWQRmFtu98FCfRDj6z1T5AsUZg== X-Google-Smtp-Source: AGHT+IEqowVMRHCVf9ZXb1dAIIluQ3OxhsYIVJjNkQnOdq9SrGz80N4cYCOuRdXFwKizwobQGPVJK2P5N87bSNQD8gQ= X-Received: by 2002:a50:d79d:0:b0:5d0:eb21:264d with SMTP id 4fb4d7f45d1cf-5d92bc4a158mr88175a12.1.1736169046950; Mon, 06 Jan 2025 05:10:46 -0800 (PST) MIME-Version: 1.0 References: <20241230175550.4046587-1-riel@surriel.com> <20241230175550.4046587-12-riel@surriel.com> <287e8a60e302929588eaf095584838fa745d69ac.camel@surriel.com> In-Reply-To: <287e8a60e302929588eaf095584838fa745d69ac.camel@surriel.com> From: Jann Horn Date: Mon, 6 Jan 2025 14:10:11 +0100 X-Gm-Features: AbW1kva4ADdHVc-5wPKzpkJujus02xjPTKRKUxwJFcEYqAfE-LgD_XoqhrOBLng Message-ID: Subject: Re: [PATCH 11/12] x86/mm: enable AMD translation cache extensions To: Rik van Riel , Sean Christopherson , Paolo Bonzini , KVM list , Tom Lendacky Cc: x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, akpm@linux-foundation.org, nadav.amit@gmail.com, zhengqi.arch@bytedance.com, linux-mm@kvack.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: E3DBB8000A X-Stat-Signature: jp9b5fzqu5bwxkhauahrr7yroay316wu X-Rspam-User: X-Rspamd-Server: rspam11 X-HE-Tag: 1736169048-96178 X-HE-Meta: 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 7DMo1Hnc QHjs8M5IsDPj0RF9ohsn6J0n48G7yuWoulYHMgEV3D4hjLNlfVfznl6Ds6Jdkly/aTqYBQnP/AQwViPYkzT/ujqC5dY3BadkI1FJgi4GaALAYSCSSRFmSVqP8F3F+9q3h+JIGJBimpIA3xYUoLXkyn1ZkEDBbngfC/hiScwoKjPBbpDytwznkMOI3FysfjsOvtOdH4BWmy0guyYTYs553m0BRqiZXLYvYHGAELhVj4uv8x2unAIOGWOTa1R9vXuopfKd0dOpliuUS7d4hrd0pmLNGaOv4c9r16Caln1TFvWtc0gxOX0QZ+63gs/UJb12NmphXhu7L/f5InHxGqj3ZbicNRrm6CRRXfjhT X-Bogosity: Ham, tests=bogofilter, spamicity=0.000022, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: +KVM/SVM folks in case they know more about how enabling CPU features interacts with virtualization; original patch is at https://lore.kernel.org/all/20241230175550.4046587-12-riel@surriel.com/ On Sat, Jan 4, 2025 at 4:08=E2=80=AFAM Rik van Riel wrot= e: > On Fri, 2025-01-03 at 18:49 +0100, Jann Horn wrote: > > On Mon, Dec 30, 2024 at 6:53=E2=80=AFPM Rik van Riel > > > only those upper-level entries that lead to the target PTE in > > > the page table hierarchy, leaving unrelated upper-level entries > > > intact. > > > > How does this patch interact with KVM SVM guests? > > In particular, will this patch cause TLB flushes performed by guest > > kernels to behave differently? > > > That is a good question. > > A Linux guest should be fine, since Linux already > flushes the parts of the TLB where page tables are > being freed. > > I don't know whether this could potentially break > some non-Linux guests, though.