From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (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 442C11A706B for ; Thu, 15 Aug 2024 15:16:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723735001; cv=none; b=TpUr+BeeFnU5fcQRfVcqbtp1fCz3n9WOrcnrlYdgw4Uth5xFNZiEP24tYbQc4I01v1ECBc10fjSz9OgztSCe7mcWLZePU+7nOYTKrvakbtpzPqTDsOQyj0JVrt+igZi8snXq9iV/6anH8ufJR05GZx0sx8dzT6bA6OozLHm27es= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723735001; c=relaxed/simple; bh=p41m5YvSjQgQm0tkYUYL+QWq1GHejmaKGY1AgryhcvY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=gUN6WzqZsngg1kVwFt/eiSmWHlc+Wg2S4djo1Skr59ncubxWq71wpYVhuyJrIrg/0iJc4DJzKADHNsm+MM7wFD0I6nBuJQzBV+TwzN9+hCUbzOCPCt6cWnDJg2z4Yg0zjaE0/hEvfmd0yU404lpTALRNCVwpwnJG0vP+7WdoBGU= 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=FfT6r+Uc; arc=none smtp.client-ip=209.85.128.202 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="FfT6r+Uc" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-6b198ecf931so421347b3.1 for ; Thu, 15 Aug 2024 08:16:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1723734999; x=1724339799; 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=p41m5YvSjQgQm0tkYUYL+QWq1GHejmaKGY1AgryhcvY=; b=FfT6r+UcQKRbDGDpXZVInCWT+bvz8y/5VravLXNilCiXc9SEPhdOfUPXiV/l95mIS8 n87pfIsw4zW2PNFrrE0OE9gs/LgZYmBXrVcQGrebSoz0bH5by+9z3DoAtrXAoWVX5uhF zSQ3XBVXhQHnFa4dfl2EOiZcIqVRKUlZMfMVsFuPXuOycAScZ/PnQ6MRfSEFuG1UxCpQ oGtinl8D/SAGb0rxH6F6jBlatWOxi187HS9Ohda5YEdTi+Qz+O49CvQVsAFolT7YPSR9 itwURHhYcbFGsXU9PfOq2M7nPl7mi+YD5kjM0wQje7JLm2foqgu2DOECOrFyKKCAMdBx Dt6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723734999; x=1724339799; 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=p41m5YvSjQgQm0tkYUYL+QWq1GHejmaKGY1AgryhcvY=; b=GLVLaAtbi9IzQSDVGeM2eIxGacQTXCwSDA6ayAEAStwY+HiEVdPctqWJC3jsJGRHup 2ahuavJay1MeIwTrwiPOE4fla8JNuvf3x70V5033tpSuiUnbnmjDLkQhedJxA7iqRRns 7qFjVkYEa6mayWCSE4NrU0C+a/TKYKIKmKi2X3HIYZ8JWjof5HbEWHFVw+XHA8fZ0rvP G6JSWF+W7PU2zTfG2GMZ8PuYYTShemuEnz1SPkTBBeFve4LEFrYSh2d8pq21PgdRjUPv VbtoYgB5dDw2lhbaIcYjkhHfDY0hLXW63Tu7hdQ+HLZ7UYQJ2/30f6pzIiAlXm9nDMd5 eMCg== X-Forwarded-Encrypted: i=1; AJvYcCUr2PRq1ELuP7eTR38VH44v5QhGzSEE192CaO+c02lth01PVXvDnG2bIU+OnS9XLqX+I+A=@vger.kernel.org X-Gm-Message-State: AOJu0Yzfp5G8Uommss/t5oQcqdEnpFP+lMVl+A2vYrSF8pLIiJAvr1o+ lZmF5NOIIwypkewlHfKlM7vempkysxCHV1hhiNMfSZhLazJn247sdN3JPXRed9Y0A2e1QJmT1ks U/Q== X-Google-Smtp-Source: AGHT+IFFoxTCAf/VBwvpKjOPtp780LvH6h9NZi2W1UhdqbZyI4z9u0aCzY3G15g7VdYrZSLAaSVeTd6UZGw= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:910e:0:b0:e0b:a34d:f223 with SMTP id 3f1490d57ef6-e116cecab95mr69092276.5.1723734999238; Thu, 15 Aug 2024 08:16:39 -0700 (PDT) Date: Thu, 15 Aug 2024 08:16:37 -0700 In-Reply-To: <20240731143649.17082-1-john.allen@amd.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240731143649.17082-1-john.allen@amd.com> Message-ID: Subject: Re: [PATCH v2] KVM: x86: Advertise SUCCOR and OVERFLOW_RECOV cpuid bits From: Sean Christopherson To: John Allen Cc: pbonzini@redhat.com, kvm@vger.kernel.org, thomas.lendacky@amd.com, bp@alien8.de, mlevitsk@redhat.com, linux-kernel@vger.kernel.org, x86@kernel.org, yazen.ghannam@amd.com Content-Type: text/plain; charset="us-ascii" s/cpuid/CPUID On Wed, Jul 31, 2024, John Allen wrote: > Handling deferred, uncorrected MCEs on AMD guests is now possible with > additional support in qemu. Ensure that the SUCCOR and OVERFLOW_RECOV > bits are advertised to the guest in KVM. To host userspace, not the guest. Please add a paragraph explaining (a) what these features do, (b) why KVM doesn't need additional enabling, and (c) why KVM can't emulate these features in software (though this can be omitted if it's quite obvious from (a)).