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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB4DBC4332F for ; Wed, 8 Nov 2023 16:15:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230016AbjKHQPZ (ORCPT ); Wed, 8 Nov 2023 11:15:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229769AbjKHQPX (ORCPT ); Wed, 8 Nov 2023 11:15:23 -0500 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CD631FE1 for ; Wed, 8 Nov 2023 08:15:21 -0800 (PST) Received: by mail-pl1-x649.google.com with SMTP id d9443c01a7336-1cc5ef7e815so49798385ad.3 for ; Wed, 08 Nov 2023 08:15:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1699460121; x=1700064921; 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=hkv2aSpFw25Sjc2pDxCz5exBlHcYk4gTYVmkV2GOyQs=; b=jmM381QoHM6/g0FB4YGETIBR5O3J1Dych7X+lotMdYThzDNuBSm38Bvy2TsfZPUuBz LzlpsoZeXenCsP0R9cO1z5mCRUWbfMliqX3Z3O7dCfsTunpZ30Cgf3LrGqt/mpzbZSbW O46em/jCPUWIkZdsHEfghHGMlEzU+D2q9+JXzOIJcLoFDjOuitCNXbMB6+FW+S0LNsxc F5WUZwqo/HTJJeTLt/A3/SNIOAkpsY83aURbgEu8jX3rhG1CNmCXmqlv5kG2IL5HBNiD v9M9nQ6x4wQbc3Uuw3RJHsDPVCYkYFT/ksNlNSKDpcP6VV1dYHtf7ofUP8DUxJg0LVXp aDpQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699460121; x=1700064921; 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=hkv2aSpFw25Sjc2pDxCz5exBlHcYk4gTYVmkV2GOyQs=; b=DGszCAcm7vopUaP2MhM9qvNeC2r5fwp+tGcRzxZVYkrg5XETDPLT4kg0WK5XMm7ni0 x/B5XxTj9Jtr2WlvFgeLrbCZeLhzHYFAADNCOsnEJP/DR0zWh4AR+BRjOYzMUVhoCPFx QGsuz1MQ2zFAZCS1TmGNW21rif7jC5LEKOlGE/C68l7Fb9VcSxf0nLJtT4YhDNFWnPoO mqsLzsbndxL2BMpfTK7eHIUeE8kaYEHMLO8twerEDjljqSoQ0A8Gg9nSIxvkwrHUKj0d 4x7AJG55cG9HjDGdciAjSpluAOordXlw/JNPRUmXFDP6ojh676kXx4sadOAAFweS1Bw9 IK5w== X-Gm-Message-State: AOJu0YyMUYzJUmoVQytod9p/EjYASKPTlxx8xh6miYsRD08m3FQWKWqm JfM8+wWjjG8G9Pt25KdZW5iIS5qgiio= X-Google-Smtp-Source: AGHT+IFTaQxuB68rES3N/Ouf34zgkF8c8VJFXOJJTqeB2NI7Tbr2np/f2yCXpxs97M+wYFrZ4r8BXQsnFFA= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:903:1386:b0:1cc:5674:9177 with SMTP id jx6-20020a170903138600b001cc56749177mr37933plb.11.1699460120994; Wed, 08 Nov 2023 08:15:20 -0800 (PST) Date: Wed, 8 Nov 2023 08:15:19 -0800 In-Reply-To: <2573d04d-feff-4119-a79c-dbf9b85e62fd@amazon.com> Mime-Version: 1.0 References: <20231108111806.92604-1-nsaenz@amazon.com> <20231108111806.92604-30-nsaenz@amazon.com> <2573d04d-feff-4119-a79c-dbf9b85e62fd@amazon.com> Message-ID: Subject: Re: [RFC 29/33] KVM: VMX: Save instruction length on EPT violation From: Sean Christopherson To: Alexander Graf Cc: Nicolas Saenz Julienne , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, pbonzini@redhat.com, vkuznets@redhat.com, anelkz@amazon.com, dwmw@amazon.co.uk, jgowans@amazon.com, corbert@lwn.net, kys@microsoft.com, haiyangz@microsoft.com, decui@microsoft.com, x86@kernel.org, linux-doc@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 08, 2023, Alexander Graf wrote: > > On 08.11.23 12:18, Nicolas Saenz Julienne wrote: > > Save the length of the instruction that triggered an EPT violation in > > struct kvm_vcpu_arch. This will be used to populate Hyper-V VSM memory > > intercept messages. > > > > Signed-off-by: Nicolas Saenz Julienne > > > In v1, please do this for SVM as well :) Why? KVM caches values on VMX because VMREAD is measurable slower than memory accesses, especially when running nested. SVM has no such problems. I wouldn't be surprised if adding a "cache" is actually less performant due to increased pressure and misses on the hardware cache.