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 X-Spam-Level: X-Spam-Status: No, score=-14.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F407AC04EB9 for ; Wed, 5 Dec 2018 23:10:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7EEA20989 for ; Wed, 5 Dec 2018 23:10:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ZPt0qcNZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7EEA20989 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728759AbeLEXKP (ORCPT ); Wed, 5 Dec 2018 18:10:15 -0500 Received: from mail-ot1-f68.google.com ([209.85.210.68]:38168 "EHLO mail-ot1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727741AbeLEXKO (ORCPT ); Wed, 5 Dec 2018 18:10:14 -0500 Received: by mail-ot1-f68.google.com with SMTP id e12so20332823otl.5 for ; Wed, 05 Dec 2018 15:10:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PKWGlg2UOSjs1lv56V75iwQ/7WJY8e6vN8MAabWosoA=; b=ZPt0qcNZIB62WVzH0gyDiayM4HyGaDIXyiLFZNA5IM5WnzCEjx1+jeC3w4A6tBvKE6 8EeUYnb/IPqJnGLvX7pTeC3WeAynqdc/CkbDEbwJHeMXUJaWXFD7jWVdRrCZWrOwOiuN GeV4lbbmwuGFoXgSA5VNrTHiNQSS+TUhVfcISg42VIXk+XSk38pmu11Qzn6hPIaXsJEb G/yMsbg/5w6IqdIbmxFeW89RFmAKOPu1PbSTTHtY9VcaOM/ggIvTNwAD0YvV5nPZv6mr 10ZsgcxA2Id2wljj0eIXRRNOs/5pvHAQjdVhm7hAeLMoV8n9dIE9afBiWZjMHFIpXUwD TAuw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PKWGlg2UOSjs1lv56V75iwQ/7WJY8e6vN8MAabWosoA=; b=feDcdJ9WokzZBx7HUL2W8kpzOm7lL/Y3FL5etKkoNvJP/xxWkxDJyv3ztRjlaOvI1R TdzK89of3+2fS8SIjEInKaUyMlFFG6+0Lus3Blwioi2NXH9vYep+UJ+cV7vSkCTr67zy 2FHBtwYQrEzJEobnkMQdOyCc/SQup9c3oke4MkkuiWBynveX4YdPIkZrxdchN1Q8vDWJ WDlXXih7WAPxhpQqeV0ZrjE635aV+HLhYrymdLLQ086q9N4aANt7n5zk+0YBczFS8yr7 DRC9v6uJXhtLxBnZyL5PKyNt3b8W3nlY9YcKb4rPG/5F/vPbeJ4H7C0FDoOSyTtyDCkv pZNQ== X-Gm-Message-State: AA+aEWaIKaY+KMCAAsMj0kISLsxTf8NBAGvvlm8+6n3ITXyzJK72fZC+ wzrQaJ9IYMCou3uGqbxvdyJzsFkFIbiCBSeCekE4sQ== X-Google-Smtp-Source: AFSGD/X2llRnM9ET7rdCH4YdW88RrUlXNDacnBSDaGl9RM0ixx72CLvGhuNf4bL9/ZezHkNF6q65bVXQ2Jvw0BC+0+U= X-Received: by 2002:a9d:bee:: with SMTP id 101mr17358342oth.120.1544051413740; Wed, 05 Dec 2018 15:10:13 -0800 (PST) MIME-Version: 1.0 References: <1543829467-18025-1-git-send-email-karahmed@amazon.de> <1543829467-18025-3-git-send-email-karahmed@amazon.de> In-Reply-To: <1543829467-18025-3-git-send-email-karahmed@amazon.de> From: Jim Mattson Date: Wed, 5 Dec 2018 15:10:02 -0800 Message-ID: Subject: Re: [PATCH v4 02/14] X86/nVMX: handle_vmptrld: Copy the VMCS12 directly from guest memory To: KarimAllah Ahmed Cc: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Paolo Bonzini , LKML , kvm list Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 3, 2018 at 1:31 AM KarimAllah Ahmed wrote: > > Copy the VMCS12 directly from guest memory instead of the map->copy->unmap > sequence. This also avoids using kvm_vcpu_gpa_to_page() and kmap() which > assumes that there is a "struct page" for guest memory. > > Signed-off-by: KarimAllah Ahmed > --- > v3 -> v4: > - Return VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID on failure (jmattson@) > v1 -> v2: > - Massage commit message a bit. > --- > arch/x86/kvm/vmx.c | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index b84f230..75817cb 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -9301,20 +9301,22 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) > return 1; > > if (vmx->nested.current_vmptr != vmptr) { > - struct vmcs12 *new_vmcs12; > - struct page *page; > - page = kvm_vcpu_gpa_to_page(vcpu, vmptr); > - if (is_error_page(page)) > - return nested_vmx_failInvalid(vcpu); > + struct vmcs12 *new_vmcs12 = (struct vmcs12 *)__get_free_page(GFP_KERNEL); > + > + if (!new_vmcs12 || > + kvm_read_guest(vcpu->kvm, vmptr, new_vmcs12, > + sizeof(*new_vmcs12))) { Isn't this a lot slower than kmap() when there is a struct page? > + free_page((unsigned long)new_vmcs12); > + return nested_vmx_failValid(vcpu, > + VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID); I agree with David that this isn't the right thing to do for -ENOMEM.