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 75962218EB1 for ; Fri, 18 Apr 2025 17:19:16 +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=1744996758; cv=none; b=V1aknqthQq/bQurpMIIpkT7y4FnHUZuXqWU7wrC4zDW8/ORd3mA08vkmJi+6T4PuSpN1P2hQ/WbBieJ6wgxNsFtxu/zXD4eMOAw45c1m6+CKu4VgG5QdKoj+mJ/oddkftmiZYgLF37AHIbLHoEUZLjdfcbLpa5y+HUTFQynd/pk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744996758; c=relaxed/simple; bh=umH6ywsc4drx9G9NcplmJ0TyaUjkmwExCrK7GVRNt5w=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=MaCx4l8Q8rDhEB43sW3xZu0k7UGk4F6JeBt0gTjsnX1XDf69Qd9raSmVor6LHH3dWkYTrJl9ZAw3bbJ2/LcVgqbV55aLmXKBMzNhTeE0VBoTOvvN7E27xGgBB3NNVMHHU21AxeQKb48BWivSbrBzIAcS/GEDkWcVh4swBtGYvO8= 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=VT3MPZzZ; 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="VT3MPZzZ" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-3086107d023so2074475a91.2 for ; Fri, 18 Apr 2025 10:19:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1744996756; x=1745601556; 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=JAMiTnJq5wGTimzHorBniJSJQObCz8zh4bLLKuMUOgs=; b=VT3MPZzZ3msHT1dZ/LgMoKOu7PthXRi4XQgX2oplccXQv3iA/oYjAnqreKsJhXDPvW NYgMmMwlg7bAI+OMZOSnJVnX6bYLt2cR6t5y9m2bYKaCAx1BdpBkB4P2lrQ9xCUu1YUp jK3SSdxDxNpzXm2vq8fVYMdylRQiXpRe9iV+rniQLGTdVsOeuiVAd4DPXGOrJBQ6ICZV mmkRP8hbixGpBm4htemOKsJOilwLR7qRNZNJ4GNVV2f7pU9HULWijOKsVgwy7/zUukkP OE3PGk2FlzbCDVDIaIw/5Ke3P/mjpV9XiKIMu1xlTL24VQzZ3rGb+q4JTf62To2r29mo PSag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744996756; x=1745601556; 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=JAMiTnJq5wGTimzHorBniJSJQObCz8zh4bLLKuMUOgs=; b=rTo19G1WmgiPrsNriZTKb3nqnJjaFMAg4NwKCle2HaoRnWKvQW6f+6OArqyGS1APyH 59EwoMkwMOoGCvyoECbDqCk9O4kMVPr12HzmwflhvpBR+A+aa10zTBzeOIvqXBYODt4/ GG6iLa2jh35CV1S62kCy4UM3233norFjnQXYtdWSH3K39XwqnDg9ta/CEARhytdKUJgw a0Ys0GIP5J73BJfwOgozFqIQdwo7XJ0zZbhQdpWO/KF8MexTPbd1kbwp0b5p2x0YAqqY ZPywl9uiCmNwF7k2tinIr+RAUDz4ixWHH+7I1EqcWjyoqrwLwRaitqN0hv6NeD6WrjS+ dwIg== X-Forwarded-Encrypted: i=1; AJvYcCXwByW+e8SR+kXZ0R3sU2Swtv1HdSSCITavkvpeeO+9rrpkYnUjxsZ+x4E2rBq/Pxv3ZmLlSwx9QAf4uOY=@vger.kernel.org X-Gm-Message-State: AOJu0YxvFmFBC0c3kAO0DdmxJ+8kKe2ZcsyAahSuIiMu/y7zNNhMH+YL 2PJDIo0hb4dgqvM6ipWqE1zG69FOd57f5ah7cIrYEAmjS8ptEhLKn/iGIp8UQuEvE0FgQHQ3GMF /bQ== X-Google-Smtp-Source: AGHT+IFYpkpjQzZ7Z5ctAJdgsF/swLP7xsl0a2d3B1YurqSDpfIGlQl4nOWEChP8tGh5x1hWI4qHIsV7y44= X-Received: from pjbee4.prod.google.com ([2002:a17:90a:fc44:b0:308:7499:3dfc]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:37c5:b0:2fe:8902:9ecd with SMTP id 98e67ed59e1d1-3087bb3e830mr4814615a91.1.1744996755737; Fri, 18 Apr 2025 10:19:15 -0700 (PDT) Date: Fri, 18 Apr 2025 10:19:14 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250331143710.1686600-1-sashal@kernel.org> <20250331143710.1686600-2-sashal@kernel.org> Message-ID: Subject: Re: [PATCH AUTOSEL 5.10 2/6] x86/cpu: Don't clear X86_FEATURE_LAHF_LM flag in init_amd_k8() on AMD when running in a virtual machine From: Sean Christopherson To: Pavel Machek Cc: Sasha Levin , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Max Grobecker , Ingo Molnar , Borislav Petkov , tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, thomas.lendacky@amd.com, perry.yuan@amd.com, mario.limonciello@amd.com, riel@surriel.com, mjguzik@gmail.com, darwi@linutronix.de Content-Type: text/plain; charset="us-ascii" On Fri, Apr 18, 2025, Pavel Machek wrote: > Hi! > > > From: Max Grobecker > > > > [ Upstream commit a4248ee16f411ac1ea7dfab228a6659b111e3d65 ] > > > This can prevent some docker containers from starting or build scripts to create > > unoptimized binaries. > > > > Admittably, this is more a small inconvenience than a severe bug in the kernel > > and the shoddy scripts that rely on parsing /proc/cpuinfo > > should be fixed instead. Uh, and the hypervisor too? Why is the hypervisor enumerating an old K8 CPU for what appears to be a modern workload? > I'd say this is not good stable candidate. Eh, practically speaking, there's no chance of this causing problems. The setup is all kinds of weird, but AIUI, K8 CPUs don't support virtualization so there's no chance that the underlying CPU is actually affected by the K8 bug, because the underlying CPU can't be K8. And no bare metal CPU will ever set the HYPERVISOR bit, so there won't be false positives on that front. I personally object to the patch itself; it's not the kernel's responsibility to deal with a misconfigured VM. But unless we revert the commit, I don't see any reason to withhold this from stable@.