From patchwork Sat Jan 9 00:47:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 12007841 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=-26.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 C81FBC4332B for ; Sat, 9 Jan 2021 00:50:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 984D823B09 for ; Sat, 9 Jan 2021 00:50:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726886AbhAIAtp (ORCPT ); Fri, 8 Jan 2021 19:49:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726960AbhAIAtj (ORCPT ); Fri, 8 Jan 2021 19:49:39 -0500 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF7B7C0617AA for ; Fri, 8 Jan 2021 16:48:08 -0800 (PST) Received: by mail-yb1-xb4a.google.com with SMTP id o8so17219460ybq.22 for ; Fri, 08 Jan 2021 16:48:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=fVKJcIBGyQ8ofth+2r+58SAdhl2FPbPE0WCNDEMMDk4=; b=sV2kXazNx3+wC2Yq0tFCfvFkxuQ8uXG6rdN9zX9NROD55PWnPh0AprGhmarvvrE/Ks srn/Y6hNixdWjZTmVJ7muGoFZ8Y2hVc645/zNmkyR+beufPJ/zSPTPJuLharLBkugmvg kBwiMT3XRfhsnHEuUNh8KkhGlHZwZX8EijET8Vi0AkNpX28n/ZQij+4/fdsEhC5K161y YrtOpmHIbDWQ6sIYluL6KJfdJo4h2nER3g3BkRS2UvRgqMbQjNBMWM1LAovL62/sCMKI 1GM+jxKOyBr3luJeuF1iy4bYYqD6cdjeBXn3RSgV67SvlDWQutqGDxRzBaSIGFCh5hKg 6EAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=fVKJcIBGyQ8ofth+2r+58SAdhl2FPbPE0WCNDEMMDk4=; b=kb+ks/q4x41HHuxd3/rcwqrxmmqlHstAMAL7J2HC94h5Y+GvmSZ/SFzGHEURtZGTi3 y5zfVQ0DJMuOEcViGRCEFhaiaCYoxNKkmNeCBGzmCyzgvRR3K5mglizsq3tzwS5+1Cfd CQcf6p0YrkhzJ1s7udP6dFHVbDv1az5jn6GvJD1pQ4dxYgf25h0YxKZfxQ3/Y70SuIri vnGxRaB7VDQt5y2vRDWlAOMARDD67RMaEPidekdeF7dUVzf/Zx8XRR6rHZHS7RYPk60w lcrGqzQOrfIywBZnzT/DY/OEakTMdczdQmv0+LjQJnZpWKdmhtxlmc3wtRxeaxI7vLpA Rjpg== X-Gm-Message-State: AOAM530jtY+a8Am46MaO2xwqzqO3JTHXMeZG25PD4z2On0RwIjo9dsvr AjbzorYA5gI3oAGSUuOfvGL8TjpP0Qk= X-Google-Smtp-Source: ABdhPJwkUpCfLMqhX7OFP7/TPxLCfPGVqnIV++qq6RbW6+AzZ8TZu4ZGF0NRg7hqrAiAuHqTHJm1tlBGHBk= Sender: "seanjc via sendgmr" X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:1ea0:b8ff:fe73:50f5]) (user=seanjc job=sendgmr) by 2002:a25:3ac3:: with SMTP id h186mr8587398yba.155.1610153288080; Fri, 08 Jan 2021 16:48:08 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 8 Jan 2021 16:47:14 -0800 In-Reply-To: <20210109004714.1341275-1-seanjc@google.com> Message-Id: <20210109004714.1341275-14-seanjc@google.com> Mime-Version: 1.0 References: <20210109004714.1341275-1-seanjc@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH 13/13] KVM: SVM: Skip SEV cache flush if no ASIDs have been used From: Sean Christopherson To: Paolo Bonzini , Dave Hansen , Andy Lutomirski , Peter Zijlstra Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Tom Lendacky , Borislav Petkov , Brijesh Singh Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Skip SEV's expensive WBINVD and DF_FLUSH if there are no SEV ASIDs waiting to be reclaimed, e.g. if SEV was never used. This "fixes" an issue where the DF_FLUSH fails during hardware teardown if the original SEV_INIT failed. Ideally, SEV wouldn't be marked as enabled in KVM if SEV_INIT fails, but that's a problem for another day. Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/sev.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index b4a9c12cf8ce..eb8e4dca4bf2 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -51,9 +51,14 @@ struct enc_region { unsigned long size; }; -static int sev_flush_asids(void) +static int sev_flush_asids(int min_asid, int max_asid) { - int ret, error = 0; + int ret, pos, error = 0; + + /* Check if there are any ASIDs to reclaim before performing a flush */ + pos = find_next_bit(sev_reclaim_asid_bitmap, max_sev_asid, min_asid); + if (pos >= max_asid) + return -EBUSY; /* * DEACTIVATE will clear the WBINVD indicator causing DF_FLUSH to fail, @@ -75,14 +80,7 @@ static int sev_flush_asids(void) /* Must be called with the sev_bitmap_lock held */ static bool __sev_recycle_asids(int min_asid, int max_asid) { - int pos; - - /* Check if there are any ASIDs to reclaim before performing a flush */ - pos = find_next_bit(sev_reclaim_asid_bitmap, max_sev_asid, min_asid); - if (pos >= max_asid) - return false; - - if (sev_flush_asids()) + if (sev_flush_asids(min_asid, max_asid)) return false; /* The flush process will flush all reclaimable SEV and SEV-ES ASIDs */ @@ -1316,10 +1314,10 @@ void sev_hardware_teardown(void) if (!sev_enabled) return; + sev_flush_asids(0, max_sev_asid); + bitmap_free(sev_asid_bitmap); bitmap_free(sev_reclaim_asid_bitmap); - - sev_flush_asids(); } int sev_cpu_init(struct svm_cpu_data *sd)