From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (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 3DF301A4F1C for ; Thu, 15 Aug 2024 15:16:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723735001; cv=none; b=qkuXO0ZyaZ7FvvSOsNoyeK4luIOvXX3bFTmGysi4BIW+oTihefndOgUmej9sQtSTBzzVCDY4eg9petPrs32HQSMHANGf4faTsuKz7O+bhmOlb2l/HUaped5eWtTw2gHyxQ4ZjJ1Gr/QY0YW5fS05uMB8X0XdRQU3OKkzg7FS+zM= 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=209.85.219.201 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-yb1-f201.google.com with SMTP id 3f1490d57ef6-e035f7b5976so2159200276.0 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=b9r3gj5oGMxsqLtxp7Aln9i2xYUD4+6XJb23+5d47X1bO3f5iDqm0/sf2X9wx5c6AK QAWsEseXgCT6Zk4RclneQCIMv+9G4XscIHwrqCbtc72Ijtbz1xyEkfkDmmZXuqjfprrx PFJP8uNv/S0IlJ3Q5+C0I7ssHYRuYK5LOwYCl2L5axw34ZasttRMrxWtn7VN7a5B7nk3 +bcK/vmtTzoBtEZzI3nIN1fmQZ6rsNFoaxQXThf3O4tJCEQ9THqUCn7ztd6tIHkKZJOt sU2tUonoZSgIIcJAxRRswQJqk0vekXp5r+peGQ2Eq3fO6wCd8Et4eydhk+uwy1Gcr71h FFLA== X-Forwarded-Encrypted: i=1; AJvYcCXxenOgb7hpyRL/zop7Ok331Ok1eL0Aem+GDfj7V999ro64zSJNlUZDdmA/EsG0lVKTZcAe34iAacnnr6c=@vger.kernel.org X-Gm-Message-State: AOJu0YyLTFI22jfZtgcQC9vWDkWfIP3eOktZu6a4CqwLSqNER9Xo1COM 8pFCTs9ZOhMpKfmVL7XrZ/5u9of8coUU+gHsKwH4gAZ3rk+Rya1NfSzWwTqQ9AcyY3aMv7gP5iO fbg== 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: linux-kernel@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)).