From patchwork Thu Nov 18 07:25:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 12626111 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75423C433F5 for ; Thu, 18 Nov 2021 07:25:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4CAED61A89 for ; Thu, 18 Nov 2021 07:25:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243447AbhKRH2g (ORCPT ); Thu, 18 Nov 2021 02:28:36 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:59220 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229914AbhKRH2f (ORCPT ); Thu, 18 Nov 2021 02:28:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1637220335; 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; bh=WqErHdfxUiLKqF/HEdQc/BLEInPll3lUng20RpVCeYg=; b=et/q8py3s4rBMUn3GUMNgO5LFP5SKwIKjiIjuxKzWGxoO4rVvtJbDKJDubKXK0aHBBRFKv zGHDjhmesEyvX6mDMVvalbpc3s2tp4UmuVteV0tDb5Lx8moUTbfGoNeRoB2EInGgdRqzIE USGIGblyjPhIU+efqRQ8XmLN6c0pWvk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-61-4EN42HLVNSardqcQ0GBPpg-1; Thu, 18 Nov 2021 02:25:33 -0500 X-MC-Unique: 4EN42HLVNSardqcQ0GBPpg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 377341006AA0; Thu, 18 Nov 2021 07:25:32 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id BED46604CC; Thu, 18 Nov 2021 07:25:31 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: stable@vger.kernel.org, Sean Christopherson Subject: [PATCH v2] KVM: x86: check PIR even for vCPUs with disabled APICv Date: Thu, 18 Nov 2021 02:25:31 -0500 Message-Id: <20211118072531.1534938-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The IRTE for an assigned device can trigger a POSTED_INTR_VECTOR even if APICv is disabled on the vCPU that receives it. In that case, the interrupt will just cause a vmexit and leave the ON bit set together with the PIR bit corresponding to the interrupt. Right now, the interrupt would not be delivered until APICv is re-enabled. However, fixing this is just a matter of always doing the PIR->IRR synchronization, even if the vCPU has temporarily disabled APICv. This is not a problem for performance, or if anything it is an improvement. First, in the common case where vcpu->arch.apicv_active is true, one fewer check has to be performed. Second, static_call_cond will elide the function call if APICv is not present or disabled. Finally, in the case for AMD hardware we can remove the sync_pir_to_irr callback: it is only needed for apic_has_interrupt_for_ppr, and that function already has a fallback for !APICv. Cc: stable@vger.kernel.org Co-developed-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Sean Christopherson --- arch/x86/kvm/lapic.c | 2 +- arch/x86/kvm/svm/svm.c | 1 - arch/x86/kvm/x86.c | 18 +++++++++--------- 3 files changed, 10 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 759952dd1222..f206fc35deff 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -707,7 +707,7 @@ static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu) static int apic_has_interrupt_for_ppr(struct kvm_lapic *apic, u32 ppr) { int highest_irr; - if (apic->vcpu->arch.apicv_active) + if (kvm_x86_ops.sync_pir_to_irr) highest_irr = static_call(kvm_x86_sync_pir_to_irr)(apic->vcpu); else highest_irr = apic_find_highest_irr(apic); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 5630c241d5f6..d0f68d11ec70 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4651,7 +4651,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = { .load_eoi_exitmap = svm_load_eoi_exitmap, .hwapic_irr_update = svm_hwapic_irr_update, .hwapic_isr_update = svm_hwapic_isr_update, - .sync_pir_to_irr = kvm_lapic_find_highest_irr, .apicv_post_state_restore = avic_post_state_restore, .set_tss_addr = svm_set_tss_addr, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 627c955101a0..a8f12c83db4b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4448,8 +4448,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) { - if (vcpu->arch.apicv_active) - static_call(kvm_x86_sync_pir_to_irr)(vcpu); + static_call_cond(kvm_x86_sync_pir_to_irr)(vcpu); return kvm_apic_get_state(vcpu, s); } @@ -9528,8 +9527,7 @@ static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu) if (irqchip_split(vcpu->kvm)) kvm_scan_ioapic_routes(vcpu, vcpu->arch.ioapic_handled_vectors); else { - if (vcpu->arch.apicv_active) - static_call(kvm_x86_sync_pir_to_irr)(vcpu); + static_call_cond(kvm_x86_sync_pir_to_irr)(vcpu); if (ioapic_in_kernel(vcpu->kvm)) kvm_ioapic_scan_entry(vcpu, vcpu->arch.ioapic_handled_vectors); } @@ -9802,10 +9800,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) /* * This handles the case where a posted interrupt was - * notified with kvm_vcpu_kick. + * notified with kvm_vcpu_kick. Assigned devices can + * use the POSTED_INTR_VECTOR even if APICv is disabled, + * so do it even if !kvm_vcpu_apicv_active(vcpu). */ - if (kvm_lapic_enabled(vcpu) && vcpu->arch.apicv_active) - static_call(kvm_x86_sync_pir_to_irr)(vcpu); + if (kvm_lapic_enabled(vcpu)) + static_call_cond(kvm_x86_sync_pir_to_irr)(vcpu); if (kvm_vcpu_exit_request(vcpu)) { vcpu->mode = OUTSIDE_GUEST_MODE; @@ -9849,8 +9849,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (likely(exit_fastpath != EXIT_FASTPATH_REENTER_GUEST)) break; - if (kvm_lapic_enabled(vcpu) && kvm->arch.apicv_active) - static_call(kvm_x86_sync_pir_to_irr)(vcpu); + if (kvm_lapic_enabled(vcpu)) + static_call_cond(kvm_x86_sync_pir_to_irr)(vcpu); if (unlikely(kvm_vcpu_exit_request(vcpu))) { exit_fastpath = EXIT_FASTPATH_EXIT_HANDLED;