From mboxrd@z Thu Jan 1 00:00:00 1970 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 D1DB6C433F5 for ; Sat, 1 Oct 2022 01:00:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232949AbiJABAa (ORCPT ); Fri, 30 Sep 2022 21:00:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232870AbiJABAB (ORCPT ); Fri, 30 Sep 2022 21:00:01 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6372FAF8 for ; Fri, 30 Sep 2022 17:59:34 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id z24-20020a056a001d9800b0054667d493bdso3623517pfw.0 for ; Fri, 30 Sep 2022 17:59:34 -0700 (PDT) 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; bh=0E11MpL6SGTty3WKUuaZinB/c2Ize2TmmIc0ubmGHxI=; b=QgihTGnwFiYnFKRuH+UiepjpjJg4APHcd1IGU17rqdVZSYwxxTkSk2beb1FwD6KrGK JubLFWX96s+DzWJ8mRm2AVVniuBn7ZekEBnyDiN3TvLDmDXYaEYFagtTjqvVaW/WrmUF kZRYCPx2+/qIDiEgT4wgjMqrsKJzBFpJAfNTRY4Fy0BI1VNy090DPOBuSJ2I+3+SdIlY dqmcpYSEx3xRFwZq0S2Tfnc0i4jw97xMt6dnnbdh+TUnS9BlPLkE4SY2YaRm1r8Fu6Rt 0fZvjwEJxn6b1gloDMaJHyZYdqnobIGmBeOrHL5wICGMzOYu1bEAk46rPmq7zSv/XbXQ aWzQ== 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; bh=0E11MpL6SGTty3WKUuaZinB/c2Ize2TmmIc0ubmGHxI=; b=hjEBhSrnNGwWsrI2xGtgBrtQxeaGNqTg7guImJ1sUNmgZYalCmak2A5UZp7IqlVoJo dz1YTUu5QYX/PsF3RUMFSB7fW0YrAW4H7MYYKHwym4lWQTxC9lDk2oUaOTqpvMGhnfUk PIG2AcpD2aDpwjUZPjh2ZMsPfjNtcJM1FacxQAwJ9YRLNzo1OC6hc1kKbzs7VWGJuEoQ Ty57r+FpSOOod03R3otogEMoNfjvBcH/7HYiv6ghMlexont7As1QOGJH/D2S5kxYSHOI nFwi1kBqsz4bc/RvEsb51OZd4WueSTWjPqw/IeoS4lhyEFWB9c/GvO3vKz3efvJHOk6H 06yg== X-Gm-Message-State: ACrzQf2DW4DxKgKi9EGBIT1Q2f+p1hFXDUijE2eyk93YtJ8DDn4sQu4s IUZozU8tJgDRzNK3okbG71D0GlHkr1I= X-Google-Smtp-Source: AMsMyM5xd4LpP4RpJnL1ZlZz+D8f72c6fcZYgwlUZ+UVAQHly5Xs2TUx4gtmjHL6k4DVTKF3UcUTTpr0qeg= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a62:1684:0:b0:554:cade:6970 with SMTP id 126-20020a621684000000b00554cade6970mr11617488pfw.11.1664585973738; Fri, 30 Sep 2022 17:59:33 -0700 (PDT) Reply-To: Sean Christopherson Date: Sat, 1 Oct 2022 00:58:52 +0000 In-Reply-To: <20221001005915.2041642-1-seanjc@google.com> Mime-Version: 1.0 References: <20221001005915.2041642-1-seanjc@google.com> X-Mailer: git-send-email 2.38.0.rc1.362.ged0d419d3c-goog Message-ID: <20221001005915.2041642-10-seanjc@google.com> Subject: [PATCH v4 09/32] KVM: x86: Handle APICv updates for APIC "mode" changes via request From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Alejandro Jimenez , Suravee Suthikulpanit , Maxim Levitsky , Li RongQing Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use KVM_REQ_UPDATE_APICV to react to APIC "mode" changes, i.e. to handle the APIC being hardware enabled/disabled and/or x2APIC being toggled. There is no need to immediately update APICv state, the only requirement is that APICv be updating prior to the next VM-Enter. Making a request will allow piggybacking KVM_REQ_UPDATE_APICV to "inhibit" the APICv memslot when x2APIC is enabled. Doing that directly from kvm_lapic_set_base() isn't feasible as KVM's SRCU must not be held when modifying memslots (to avoid deadlock), and may or may not be held when kvm_lapic_set_base() is called, i.e. KVM can't do the right thing without tracking that is rightly buried behind CONFIG_PROVE_RCU=y. Suggested-by: Maxim Levitsky Signed-off-by: Sean Christopherson --- arch/x86/kvm/lapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 2503f162eb95..316b61b56cca 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2401,7 +2401,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id); if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) { - kvm_vcpu_update_apicv(vcpu); + kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu); static_call_cond(kvm_x86_set_virtual_apic_mode)(vcpu); } -- 2.38.0.rc1.362.ged0d419d3c-goog