Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934069AbeAJOHC (ORCPT + 1 other); Wed, 10 Jan 2018 09:07:02 -0500 Received: from mga02.intel.com ([134.134.136.20]:10053 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752108AbeAJOHB (ORCPT ); Wed, 10 Jan 2018 09:07:01 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,340,1511856000"; d="scan'208";a="26049365" Subject: Re: [PATCH 3/8] kvm: vmx: pass MSR_IA32_SPEC_CTRL and MSR_IA32_PRED_CMD down to the guest To: Paolo Bonzini , Nadav Amit Cc: Liran Alon , jmattson@google.com, x86@kernel.org, dwmw@amazon.co.uk, bp@alien8.de, aliguori@amazon.com, thomas.lendacky@amd.com, rkrcmar@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org References: <222d0a6b-820f-4d7c-a616-ac89f77c3c09@default> <834e9b46-5d59-a81e-8cda-5f576964e1cb@redhat.com> From: Arjan van de Ven Message-ID: <9360a280-228d-26d9-5561-6688aa67881c@linux.intel.com> Date: Wed, 10 Jan 2018 06:06:59 -0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 1/10/2018 5:20 AM, Paolo Bonzini wrote: > * a simple specification that does "IBRS=1 blocks indirect branch > prediction altogether" would actually satisfy the specification just as > well, and it would be nice to know if that's what the processor actually > does. it doesn't exactly, not for all. so you really do need to write ibrs again.