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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 D5A2DC388F4 for ; Fri, 27 Sep 2019 21:45:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ABF302146E for ; Fri, 27 Sep 2019 21:45:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728588AbfI0Vp3 (ORCPT ); Fri, 27 Sep 2019 17:45:29 -0400 Received: from mga12.intel.com ([192.55.52.136]:45953 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728513AbfI0Vp0 (ORCPT ); Fri, 27 Sep 2019 17:45:26 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Sep 2019 14:45:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,557,1559545200"; d="scan'208";a="196852066" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.41]) by FMSMGA003.fm.intel.com with ESMTP; 27 Sep 2019 14:45:25 -0700 From: Sean Christopherson To: Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Reto Buerki , Liran Alon Subject: [PATCH v2 4/8] KVM: VMX: Optimize vmx_set_rflags() for unrestricted guest Date: Fri, 27 Sep 2019 14:45:19 -0700 Message-Id: <20190927214523.3376-5-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190927214523.3376-1-sean.j.christopherson@intel.com> References: <20190927214523.3376-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rework vmx_set_rflags() to avoid the extra code need to handle emulation of real mode and invalid state when unrestricted guest is disabled. The primary reason for doing so is to avoid the call to vmx_get_rflags(), which will incur a VMREAD when RFLAGS is not already available. When running nested VMs, the majority of calls to vmx_set_rflags() will occur without an associated vmx_get_rflags(), i.e. when stuffing GUEST_RFLAGS during transitions between vmcs01 and vmcs02. Note, vmx_get_rflags() guarantees RFLAGS is marked available. Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 83fe8b02b732..814d3e6d0264 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1426,18 +1426,26 @@ unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu) void vmx_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags) { struct vcpu_vmx *vmx = to_vmx(vcpu); - unsigned long old_rflags = vmx_get_rflags(vcpu); + unsigned long old_rflags; - __set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail); - vmx->rflags = rflags; - if (vmx->rmode.vm86_active) { - vmx->rmode.save_rflags = rflags; - rflags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM; + if (enable_unrestricted_guest) { + __set_bit(VCPU_EXREG_RFLAGS, (ulong *)&vcpu->arch.regs_avail); + + vmx->rflags = rflags; + vmcs_writel(GUEST_RFLAGS, rflags); + } else { + old_rflags = vmx_get_rflags(vcpu); + + vmx->rflags = rflags; + if (vmx->rmode.vm86_active) { + vmx->rmode.save_rflags = rflags; + rflags |= X86_EFLAGS_IOPL | X86_EFLAGS_VM; + } + vmcs_writel(GUEST_RFLAGS, rflags); + + if ((old_rflags ^ vmx->rflags) & X86_EFLAGS_VM) + vmx->emulation_required = emulation_required(vcpu); } - vmcs_writel(GUEST_RFLAGS, rflags); - - if ((old_rflags ^ vmx->rflags) & X86_EFLAGS_VM) - vmx->emulation_required = emulation_required(vcpu); } u32 vmx_get_interrupt_shadow(struct kvm_vcpu *vcpu) -- 2.22.0