From patchwork Thu Jan 14 00:37:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 12018147 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=-26.3 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 3AA4EC433E0 for ; Thu, 14 Jan 2021 01:48:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D788E2343B for ; Thu, 14 Jan 2021 01:48:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728366AbhANBsN (ORCPT ); Wed, 13 Jan 2021 20:48:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729698AbhANAlN (ORCPT ); Wed, 13 Jan 2021 19:41:13 -0500 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 450D1C061389 for ; Wed, 13 Jan 2021 16:38:11 -0800 (PST) Received: by mail-qt1-x84a.google.com with SMTP id e14so2973877qtr.8 for ; Wed, 13 Jan 2021 16:38:11 -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=GWAuLMH7Ls1Ey0iR5g9WiKswv9AMybZldn+rr0xf6ac=; b=EA5dGny0b2252/x6CNsCPKBTA7REUvSuQY/vkBnPivTVuhM8e9yuI+i12+7oOOBfFs Odc8VO6oCuwkhgHeMO+Kxl6qhi2hPsfF3AMD/AelinGodE7PUAjSE2Hbn6mYPuzD+w4d LW+nnVBmYuL7Q9TFywnfbudkkng1w4GhDAzXOBhadAtiu9hGgckJrjPvsivW2pFpifvX h6E0oo6T0I6oQ0JDleuIMT5bTm+bToe6ZTjz8pFVJZzaiJJwRGcqDwuTYFwkyCcriWBq RRUBgVnbMg3apSIZ/HOwOt7LW/AeIm7+/suFXahOMBLws5n4KwAcBrIv8PxRySYRViTF k6Bw== 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=GWAuLMH7Ls1Ey0iR5g9WiKswv9AMybZldn+rr0xf6ac=; b=HABQokuQez8XvMNdQoUIwfZjGNjpsdy6ROCqygbx+hUKOQ2fni19TZxL7gACn/4687 8fMh86hwssMZ7DVPqyKOM0Q6fFjnNJ0LHjMddlAYfVzYA4XGsuOGDCTdexFvSB0Q1ySu fe7lTDV1XUGIg8k9DAY3BNrdGIxZF7Os/2brPqv8AI3OigSCs3hE8KdZj2jh8r5IF9BS yCVKRYbtx66lNvTHgS36PXO2YQH+CJz3SDV7A88+2DgcuhyRD2smx+QduovoonC5m02C O8VeX9jkfEoEIcYnVxnObIR4mKjQpPre+qVPyyrmUZDMIqfVtZSReZXva7djY+ouQmao 6w/A== X-Gm-Message-State: AOAM5306Nbf9MGOCgFMavMz56bSHHcYHA2MW4CcbJgjKXioMTPStkA+5 LUpUnQ1/h7ikbVqqNukYCJouNgKNTdE= X-Google-Smtp-Source: ABdhPJxd26knuMip8++7sqtHgt8IOL56+LllnVUDn9Zy+jMdU8upn1suW+wnmfnhT20jDRW580FRWd3GuJ0= 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:cf08:: with SMTP id f8mr7105191ybg.210.1610584690440; Wed, 13 Jan 2021 16:38:10 -0800 (PST) Reply-To: Sean Christopherson Date: Wed, 13 Jan 2021 16:37:08 -0800 In-Reply-To: <20210114003708.3798992-1-seanjc@google.com> Message-Id: <20210114003708.3798992-15-seanjc@google.com> Mime-Version: 1.0 References: <20210114003708.3798992-1-seanjc@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH v2 14/14] 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, Borislav Petkov , Tom Lendacky , 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 23a4bead4a82..e71bc742d8da 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -56,9 +56,14 @@ 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, @@ -80,14 +85,7 @@ 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 */ @@ -1323,10 +1321,10 @@ 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)