Message ID | 20200317045238.30434-22-sean.j.christopherson@intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show
Return-Path: <SRS0=C8aH=5C=vger.kernel.org=kvm-owner@kernel.org> Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 02DB91668 for <patchwork-kvm@patchwork.kernel.org>; Tue, 17 Mar 2020 04:54:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E230320663 for <patchwork-kvm@patchwork.kernel.org>; Tue, 17 Mar 2020 04:54:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726248AbgCQEy3 (ORCPT <rfc822;patchwork-kvm@patchwork.kernel.org>); Tue, 17 Mar 2020 00:54:29 -0400 Received: from mga04.intel.com ([192.55.52.120]:34117 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726949AbgCQExU (ORCPT <rfc822;kvm@vger.kernel.org>); Tue, 17 Mar 2020 00:53:20 -0400 IronPort-SDR: nYR2eiJM8rB468PzpJguwE52od/AyMWM3MfaM1FdBXc+UBCwUhrcHZj1smBLyRvZoknFatH7pF DQz9JJcanDMw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2020 21:53:19 -0700 IronPort-SDR: DK8Lwi9fXYsuCsnch1Nu2tPbvDX/rgWQS7eRWPcMyhxFeiKsMe+Om31vX31uIoiw6wG/5qq1Jz RfQIL5nmQgiA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,563,1574150400"; d="scan'208";a="355252803" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by fmsmga001.fm.intel.com with ESMTP; 16 Mar 2020 21:53:19 -0700 From: Sean Christopherson <sean.j.christopherson@intel.com> To: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <sean.j.christopherson@intel.com>, Vitaly Kuznetsov <vkuznets@redhat.com>, Wanpeng Li <wanpengli@tencent.com>, Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Ben Gardon <bgardon@google.com>, Junaid Shahid <junaids@google.com>, Liran Alon <liran.alon@oracle.com>, Boris Ostrovsky <boris.ostrovsky@oracle.com>, John Haxby <john.haxby@oracle.com>, Miaohe Lin <linmiaohe@huawei.com>, Tom Lendacky <thomas.lendacky@amd.com> Subject: [PATCH v2 21/32] KVM: SVM: Document the ASID logic in svm_flush_tlb() Date: Mon, 16 Mar 2020 21:52:27 -0700 Message-Id: <20200317045238.30434-22-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200317045238.30434-1-sean.j.christopherson@intel.com> References: <20200317045238.30434-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: <kvm.vger.kernel.org> X-Mailing-List: kvm@vger.kernel.org |
Series |
KVM: x86: TLB flushing fixes and enhancements
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diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index dfa3b53f8437..8c3700b44eb4 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -5630,6 +5630,13 @@ static void svm_flush_tlb(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + /* + * Flush only the current ASID even if the TLB flush was invoked via + * kvm_flush_remote_tlbs(). Although flushing remote TLBs requires all + * ASIDs to be flushed, KVM uses a single ASID for L1 and L2, and + * unconditionally does a TLB flush on both nested VM-Enter and nested + * VM-Exit (via kvm_mmu_reset_context()). + */ if (static_cpu_has(X86_FEATURE_FLUSHBYASID)) svm->vmcb->control.tlb_ctl = TLB_CONTROL_FLUSH_ASID; else
Add a comment in svm_flush_tlb() to document why it flushes only the current ASID, even when it is invoked when flushing remote TLBs. Cc: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/kvm/svm.c | 7 +++++++ 1 file changed, 7 insertions(+)