From nobody Sun Feb 8 16:31:34 2026 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 A42E1C3DA7A for ; Fri, 6 Jan 2023 01:16:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229938AbjAFBQo (ORCPT ); Thu, 5 Jan 2023 20:16:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229757AbjAFBP7 (ORCPT ); Thu, 5 Jan 2023 20:15:59 -0500 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B3A73E863 for ; Thu, 5 Jan 2023 17:14:10 -0800 (PST) Received: by mail-pg1-x549.google.com with SMTP id r126-20020a632b84000000b004393806c06eso216745pgr.4 for ; Thu, 05 Jan 2023 17:14:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=o4UAETXkM62nM2yYuGHBJ1AdJGjwtbarF4DTw13SG8M=; b=j2HNEccBP7np7M1sGlh/lR9iiwoxeu2tDdMfTtFmom/1SMGw9AQClRjRPjxLcQnERb P92ChTGaFkoInGodIaAPnUdfY53bosFhp2WBXli5H0PS/7/07MxxqJE4tVPSrQgL9zZ4 iy1PiDEc0mmhxGDEB4e9NZbEj87Xzb/ZJTKCAfEMolx9oL+EUzsxesFZVBys6msUS/dV BlERFFcesl/Aa0+XdXyltbE2MS4q6xScax+5zeprGT9eHK5nBMbpS06o+TwXC7g9SbZh y2NdVD5PQ5H5gTO6T23k2qqLzFuLP2O4eK7GOViM+89twqSlz/6vLB7iSc/KWmjVNb6L ngZw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=o4UAETXkM62nM2yYuGHBJ1AdJGjwtbarF4DTw13SG8M=; b=JSDbWrD9ACsmneEMnSvpKY+4E20r6+d6E4pO/k4nPU9msbFGlbKJcW8j0RRf9r+BZZ yUnya16QLTgCsCwRQ75Hi+kewz7KAbU/tWo9UWW1/hgvdQncKk6M1Tl+jnfvYYBjVPh4 v+MGhDHf2/4BlVoVQcAxDOjRyuAF8AXTa6vsuV04ZvhDapfTNuMevRd9mGwzXDiu0FOm Xae5sVfNUS/7vVlLUytYLskgyRzMk0GwuoqESQailk/oP8rAT4/Kv5vZUudNbOP4pJPp 1a87JiN3qknpgQyVmYqdGmP5VCXFIKJRYlvDDI8q+WTKL34yz/hgDPBFbodIrxBE7yXM qcDA== X-Gm-Message-State: AFqh2krladJi4DOtGA+m+s56lEWTikJHvgl979FgryCoAoh/I4sePL0z V1JrafXLtYsh7DQWNxg4ST6F6U8lfLs= X-Google-Smtp-Source: AMrXdXuxaeNgG3qV2/dc3S4AdIlGeqilvlmQHbJQGHhMswaBgY/s1jn0nF3f3Xk4hQBpGykQGzmLpuaPAjQ= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90a:2e05:b0:225:b536:1209 with SMTP id q5-20020a17090a2e0500b00225b5361209mr4108245pjd.101.1672967634940; Thu, 05 Jan 2023 17:13:54 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 6 Jan 2023 01:12:57 +0000 In-Reply-To: <20230106011306.85230-1-seanjc@google.com> Mime-Version: 1.0 References: <20230106011306.85230-1-seanjc@google.com> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20230106011306.85230-25-seanjc@google.com> Subject: [PATCH v5 24/33] KVM: SVM: Inhibit AVIC if vCPUs are aliased in logical mode From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Alejandro Jimenez , Maxim Levitsky , Suravee Suthikulpanit , Li RongQing , Greg Edwards Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Inhibit SVM's AVIC if multiple vCPUs are aliased to the same logical ID. Architecturally, all CPUs whose logical ID matches the MDA are supposed to receive the interrupt; overwriting existing entries in AVIC's logical=3D>physical map can result in missed IPIs. Fixes: 18f40c53e10f ("svm: Add VMEXIT handlers for AVIC") Reviewed-by: Maxim Levitsky Signed-off-by: Sean Christopherson --- arch/x86/include/asm/kvm_host.h | 6 ++++++ arch/x86/kvm/lapic.c | 5 +++++ arch/x86/kvm/svm/avic.c | 3 ++- 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_hos= t.h index 5865bad08a23..b41a01b3a4af 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1218,6 +1218,12 @@ enum kvm_apicv_inhibit { * AVIC is disabled because SEV doesn't support it. */ APICV_INHIBIT_REASON_SEV, + + /* + * AVIC is disabled because not all vCPUs with a valid LDR have a 1:1 + * mapping between logical ID and vCPU. + */ + APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED, }; =20 struct kvm_arch { diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 297da684c25f..0faf80cdc1be 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -396,6 +396,11 @@ void kvm_recalculate_apic_map(struct kvm *kvm) else kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED); =20 + if (!new || new->logical_mode =3D=3D KVM_APIC_MODE_MAP_DISABLED) + kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED); + else + kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED); + old =3D rcu_dereference_protected(kvm->arch.apic_map, lockdep_is_held(&kvm->arch.apic_map_lock)); rcu_assign_pointer(kvm->arch.apic_map, new); diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index d1ac19f053ce..1fd473a57159 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -967,7 +967,8 @@ bool avic_check_apicv_inhibit_reasons(enum kvm_apicv_in= hibit reason) BIT(APICV_INHIBIT_REASON_SEV) | BIT(APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED) | BIT(APICV_INHIBIT_REASON_APIC_ID_MODIFIED) | - BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED); + BIT(APICV_INHIBIT_REASON_APIC_BASE_MODIFIED) | + BIT(APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED); =20 return supported & BIT(reason); } --=20 2.39.0.314.g84b9a713c41-goog