From patchwork Wed Apr 27 20:02:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 12829490 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3959BC4332F for ; Wed, 27 Apr 2022 20:03:47 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B4FC610E367; Wed, 27 Apr 2022 20:03:45 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4140F10E33A for ; Wed, 27 Apr 2022 20:03:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1651089820; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=d3HuyXBj7sbCyPJII4k+rhKVq+N2QJKVq0tQDMGX/Io=; b=GcRkOj24qrxd3yDptZ3EenF8elMiQ9OfTfrILX59eJHgqY6ECkqLMyaKmX6ophzabx6Hrx GkdKEC61pNWDhkVEBvHT9Jtd09E7db/GA3Exbv7ESvE3oc7FkNKvkO/TNRwnjlVUgdWhMM LSHfDEPJZsFWNyysWf3MY80fApk5MfM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-99-gDqYxOC3NJe1YVvQKWXlBQ-1; Wed, 27 Apr 2022 16:03:36 -0400 X-MC-Unique: gDqYxOC3NJe1YVvQKWXlBQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 92F9D101AA44; Wed, 27 Apr 2022 20:03:34 +0000 (UTC) Received: from localhost.localdomain (unknown [10.40.192.41]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2AE3D9E82; Wed, 27 Apr 2022 20:03:28 +0000 (UTC) From: Maxim Levitsky To: kvm@vger.kernel.org Date: Wed, 27 Apr 2022 23:02:57 +0300 Message-Id: <20220427200314.276673-3-mlevitsk@redhat.com> In-Reply-To: <20220427200314.276673-1-mlevitsk@redhat.com> References: <20220427200314.276673-1-mlevitsk@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 Subject: [Intel-gfx] [RFC PATCH v3 02/19] KVM: x86: inhibit APICv/AVIC when the guest and/or host changes apic id/base from the defaults. X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wanpeng Li , David Airlie , Dave Hansen , dri-devel@lists.freedesktop.org, "H. Peter Anvin" , Brijesh Singh , Joerg Roedel , x86@kernel.org, Maxim Levitsky , Ingo Molnar , Tom Lendacky , intel-gfx@lists.freedesktop.org, Borislav Petkov , Rodrigo Vivi , Thomas Gleixner , intel-gvt-dev@lists.freedesktop.org, Jim Mattson , Sean Christopherson , linux-kernel@vger.kernel.org, Paolo Bonzini , Vitaly Kuznetsov Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Neither of these settings should be changed by the guest and it is a burden to support it in the acceleration code, so just inhibit it instead. Also add a boolean 'apic_id_changed' to indicate if apic id ever changed. Signed-off-by: Maxim Levitsky --- arch/x86/include/asm/kvm_host.h | 3 +++ arch/x86/kvm/lapic.c | 25 ++++++++++++++++++++++--- arch/x86/kvm/lapic.h | 8 ++++++++ 3 files changed, 33 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 63eae00625bda..636df87542555 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1070,6 +1070,8 @@ enum kvm_apicv_inhibit { APICV_INHIBIT_REASON_ABSENT, /* AVIC is disabled because SEV doesn't support it */ APICV_INHIBIT_REASON_SEV, + /* APIC ID and/or APIC base was changed by the guest */ + APICV_INHIBIT_REASON_RO_SETTINGS, }; struct kvm_arch { @@ -1258,6 +1260,7 @@ struct kvm_arch { hpa_t hv_root_tdp; spinlock_t hv_root_tdp_lock; #endif + bool apic_id_changed; }; struct kvm_vm_stat { diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 66b0eb0bda94e..8996675b3ef4c 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2038,6 +2038,19 @@ static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val) } } +static void kvm_lapic_check_initial_apic_id(struct kvm_lapic *apic) +{ + if (kvm_apic_has_initial_apic_id(apic)) + return; + + pr_warn_once("APIC ID change is unsupported by KVM"); + + kvm_set_apicv_inhibit(apic->vcpu->kvm, + APICV_INHIBIT_REASON_RO_SETTINGS); + + apic->vcpu->kvm->arch.apic_id_changed = true; +} + static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) { int ret = 0; @@ -2046,9 +2059,11 @@ static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) switch (reg) { case APIC_ID: /* Local APIC ID */ - if (!apic_x2apic_mode(apic)) + if (!apic_x2apic_mode(apic)) { + kvm_apic_set_xapic_id(apic, val >> 24); - else + kvm_lapic_check_initial_apic_id(apic); + } else ret = 1; break; @@ -2335,8 +2350,11 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) MSR_IA32_APICBASE_BASE; if ((value & MSR_IA32_APICBASE_ENABLE) && - apic->base_address != APIC_DEFAULT_PHYS_BASE) + apic->base_address != APIC_DEFAULT_PHYS_BASE) { + kvm_set_apicv_inhibit(apic->vcpu->kvm, + APICV_INHIBIT_REASON_RO_SETTINGS); pr_warn_once("APIC base relocation is unsupported by KVM"); + } } void kvm_apic_update_apicv(struct kvm_vcpu *vcpu) @@ -2649,6 +2667,7 @@ static int kvm_apic_state_fixup(struct kvm_vcpu *vcpu, } } + kvm_lapic_check_initial_apic_id(vcpu->arch.apic); return 0; } diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 4e4f8a22754f9..b9c406d383080 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -252,4 +252,12 @@ static inline u8 kvm_xapic_id(struct kvm_lapic *apic) return kvm_lapic_get_reg(apic, APIC_ID) >> 24; } +static inline bool kvm_apic_has_initial_apic_id(struct kvm_lapic *apic) +{ + if (apic_x2apic_mode(apic)) + return true; + + return kvm_xapic_id(apic) == apic->vcpu->vcpu_id; +} + #endif