From nobody Sun Feb 8 17:37:52 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 5648AC3DA7A for ; Fri, 6 Jan 2023 01:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234596AbjAFBOF (ORCPT ); Thu, 5 Jan 2023 20:14:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236642AbjAFBNZ (ORCPT ); Thu, 5 Jan 2023 20:13:25 -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 48F5F71FF6 for ; Thu, 5 Jan 2023 17:13:24 -0800 (PST) Received: by mail-pg1-x549.google.com with SMTP id d10-20020a631d4a000000b00491da16dc44so198549pgm.16 for ; Thu, 05 Jan 2023 17:13:24 -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=skmNHPbTYLwyxoraHBJpLpuS512+i4UR+d4KzIFrXzo=; b=eHspZ09DmK7JKDuAkYFgw2Tmeu1pkc8IkPzAYI2GCsgpOY4NyVmsDEUKctJkeXrE5G LzYk2RkJgeauHLVZqTm7drTchkyldaitSOOoRqSr/yjfeEX5NiuSamVpMc+U2c7qLwm0 DngxD2loLWSr9XkOBdkVspM0ynT+X312xS8jTpu12DQVxNUrLf2h1jHb9Cj7PvkPYJq9 PhfxFoez2ibzGpvO7NqkRNK/0zsGH8c+GZf2gzf2Gb5NhhqUfFIKjJIioj3koUdYLD1X CU1kGCr00qZon5e991QguAtr2xKfe87a1tWqbR3kLl7vIweiPI7nyLBf2MzZ7dQo82LK Tm4A== 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=skmNHPbTYLwyxoraHBJpLpuS512+i4UR+d4KzIFrXzo=; b=ghda/v9xypluNcHAcY1xjwPKWv/Eyvmh2G0yXbT2TTQXVhiCMHzBDptGkLkRECjMiy wHvB4LC8k/3PoBA+A+lIqSzqjznPdw8XEtGluyxka3hIiknbhsqnCctz9A0G6qscDj6T YrkVvdPgRMbE7DJ/sIRTbEeRJzzfJlCALH3yPjL+Xv/bSthPwCPEQsM8EoDKXj83nqpj beDlTgysCpV72do3CRCESZgYc9ExkbQmbB7729gJBSF891khIrUgV/tgSp5b2lCgcuS8 8MOPNy3Us/Oizorz9zwQQUcIsjI/HK6uUR0UBxnKXCSkfQlPCN6fRtTM304/y6vhhm+1 g8cw== X-Gm-Message-State: AFqh2koJwcVDwmD7MrAo0KChFFcNPBsbjb8ZqckAGkgFLSkTYu2MrT+Z lnn3HT5UjTPQsgFZzRDeutA7trftnDw= X-Google-Smtp-Source: AMrXdXvwxPom+8pP9fNt6a6nAoWVR8+muMZ9FIRFEqS1HHzsnhrSJPf0g6plar5raO5p9grs5bFtPDq/NHI= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:90b:3c81:b0:219:dbed:ade9 with SMTP id pv1-20020a17090b3c8100b00219dbedade9mr4575858pjb.125.1672967603847; Thu, 05 Jan 2023 17:13:23 -0800 (PST) Reply-To: Sean Christopherson Date: Fri, 6 Jan 2023 01:12:38 +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: <20230106011306.85230-6-seanjc@google.com> Subject: [PATCH v5 05/33] KVM: x86: Don't inhibit APICv/AVIC on xAPIC ID "change" if APIC is disabled 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" Don't inhibit APICv/AVIC due to an xAPIC ID mismatch if the APIC is hardware disabled. The ID cannot be consumed while the APIC is disabled, and the ID is guaranteed to be set back to the vcpu_id when the APIC is hardware enabled (architectural behavior correctly emulated by KVM). Fixes: 3743c2f02517 ("KVM: x86: inhibit APICv/AVIC on changes to APIC ID or= APIC base") Cc: stable@vger.kernel.org Reviewed-by: Maxim Levitsky Signed-off-by: Sean Christopherson --- arch/x86/kvm/lapic.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 33a661d82da7..191b5a962700 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2072,6 +2072,9 @@ static void kvm_lapic_xapic_id_updated(struct kvm_lap= ic *apic) { struct kvm *kvm =3D apic->vcpu->kvm; =20 + if (!kvm_apic_hw_enabled(apic)) + return; + if (KVM_BUG_ON(apic_x2apic_mode(apic), kvm)) return; =20 --=20 2.39.0.314.g84b9a713c41-goog