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 08B94C433FE for ; Sat, 19 Nov 2022 01:33:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232330AbiKSBdl (ORCPT ); Fri, 18 Nov 2022 20:33:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232006AbiKSBdU (ORCPT ); Fri, 18 Nov 2022 20:33:20 -0500 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E51E415BB13 for ; Fri, 18 Nov 2022 16:37:49 -0800 (PST) Received: by mail-pf1-x449.google.com with SMTP id x11-20020a056a000bcb00b0056c6ec11eefso3954382pfu.14 for ; Fri, 18 Nov 2022 16:37:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:reply-to:from:to:cc :subject:date:message-id:reply-to; bh=qXGFKO/EkpuIeqVDphBNVjuhQ/zqYCH5ABXNmG1D7zQ=; b=jsKeef8KYLqC5oBCrTT2cPmdPYbyBgcZWYsC8Tjtf9Vil5QubiQoihVm/PBx+ruzR7 QwVuNwUGHTkeKsiG+Y4hkOmRTHJhzK4jISwRnOysFoWcOXeZD6153GkTo7VLDkCiMD9z g5U6Wutc69WUe05MvhbcYon/90cX1HO3xxkeekLBjZGqQGebpI504/Bn/FoJ3yZYXW9T 3xjkz1beKaeYcXWSA/WEefdEz8zxDl0hPPOKYqmeyjmFAfm3KKRMf99QFtdFf42zN6lO MeOvWsHHpba+S0EV+zIvejO3/mBh2Cb6j2LFa/N0bHha6nt1Hbomi+0KlVrK+it73JvX 3GXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:mime-version:date:reply-to :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=qXGFKO/EkpuIeqVDphBNVjuhQ/zqYCH5ABXNmG1D7zQ=; b=njxaeKPfgQY5EIbNmT6WTBfTOrVTCgNn4lnxintBTHeGRvciZLKrL72Utp5IHDpvcV oyZKN2dXVpR4uIseAT8VnqrU1DVx5T4mAo2DlrlgL3kHJgmDfUtu2xrXZwBF7iwe2+Z8 AW8YG3D2QjZxx0hlZjBTnRUTuJmyneU9IYe2DYQbD+zJYCUZup1FsUh7heqKcAmx+SnC FI+Z6UNmmgyxqhmlo52tVDRCkUH6jTAJaAEatisIbXbWslOlvYgbgGJIJVO/i5MONbkQ mvrE56ECWbgL20WY2k+mmYaCYS4/rMcsng/1fFCNJt8Ot7MUhp8TtmVfV3Sg4DVe2+o7 08lQ== X-Gm-Message-State: ANoB5pnU3rZ8pbXhi4/fPIKDI2aVPXzy4QBRrUMrPUFvngCmjZQo1R+d vAi836R7ENsl7YLLkRgBJgYmgomoPjs= X-Google-Smtp-Source: AA0mqf7IxIMf2B9LDq5ip8bGacxM5fpViFwU5IxlL6NRcOx+wOegVERvKTCXqg6eFFjl9iFqS9H3NsVVqx8= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a62:1cd4:0:b0:56b:deea:72e9 with SMTP id c203-20020a621cd4000000b0056bdeea72e9mr10102088pfc.47.1668818269339; Fri, 18 Nov 2022 16:37:49 -0800 (PST) Reply-To: Sean Christopherson Date: Sat, 19 Nov 2022 00:37:47 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog Message-ID: <20221119003747.2615229-1-seanjc@google.com> Subject: [PATCH] KVM: VMX: Access @flags as a 32-bit value in __vmx_vcpu_run() From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Alexey Dobriyan Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Access @flags using 32-bit operands when saving and testing @flags for VMX_RUN_VMRESUME, as using 8-bit operands is unnecessarily fragile due to relying on VMX_RUN_VMRESUME being in bits 0-7. The behavior of treating @flags a single byte is a holdover from when the param was "bool launched", i.e. is not deliberate. Cc: Alexey Dobriyan Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmenter.S | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S index 0b5db4de4d09..5bd39f63497d 100644 --- a/arch/x86/kvm/vmx/vmenter.S +++ b/arch/x86/kvm/vmx/vmenter.S @@ -69,8 +69,8 @@ SYM_FUNC_START(__vmx_vcpu_run) */ push %_ASM_ARG2 - /* Copy @flags to BL, _ASM_ARG3 is volatile. */ - mov %_ASM_ARG3B, %bl + /* Copy @flags to EBX, _ASM_ARG3 is volatile. */ + mov %_ASM_ARG3L, %ebx lea (%_ASM_SP), %_ASM_ARG2 call vmx_update_host_rsp @@ -106,7 +106,7 @@ SYM_FUNC_START(__vmx_vcpu_run) mov (%_ASM_SP), %_ASM_AX /* Check if vmlaunch or vmresume is needed */ - testb $VMX_RUN_VMRESUME, %bl + test $VMX_RUN_VMRESUME, %ebx /* Load guest registers. Don't clobber flags. */ mov VCPU_RCX(%_ASM_AX), %_ASM_CX @@ -128,7 +128,7 @@ SYM_FUNC_START(__vmx_vcpu_run) /* Load guest RAX. This kills the @regs pointer! */ mov VCPU_RAX(%_ASM_AX), %_ASM_AX - /* Check EFLAGS.ZF from 'testb' above */ + /* Check EFLAGS.ZF from 'test VMX_RUN_VMRESUME' above */ jz .Lvmlaunch /* base-commit: d663b8a285986072428a6a145e5994bc275df994 -- 2.38.1.584.g0f3c55d4c2-goog