From nobody Tue Feb 10 08:27:52 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1512719278085539.6469659267108; Thu, 7 Dec 2017 23:47:58 -0800 (PST) Received: from localhost ([::1]:35897 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eNDNu-0003lx-0D for importer@patchew.org; Fri, 08 Dec 2017 02:47:50 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58509) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eNDLh-00025A-GX for qemu-devel@nongnu.org; Fri, 08 Dec 2017 02:45:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eNDLg-0005oj-8h for qemu-devel@nongnu.org; Fri, 08 Dec 2017 02:45:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39676) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eNDLf-0005mX-Vs for qemu-devel@nongnu.org; Fri, 08 Dec 2017 02:45:32 -0500 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 mx1.redhat.com (Postfix) with ESMTPS id 1DFB983F43; Fri, 8 Dec 2017 07:45:31 +0000 (UTC) Received: from dhcp-1-107.brq.redhat.com (ovpn-204-198.brq.redhat.com [10.40.204.198]) by smtp.corp.redhat.com (Postfix) with ESMTP id 961C11964B; Fri, 8 Dec 2017 07:45:29 +0000 (UTC) From: Ladi Prosek To: qemu-devel@nongnu.org Date: Fri, 8 Dec 2017 08:45:13 +0100 Message-Id: <20171208074515.1553-3-lprosek@redhat.com> In-Reply-To: <20171208074515.1553-1-lprosek@redhat.com> References: <20171208074515.1553-1-lprosek@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 08 Dec 2017 07:45:31 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v3 2/4] ivshmem: Always remove irqfd notifiers X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: geoff@hostfission.com, pbonzini@redhat.com, armbru@redhat.com, marcandre.lureau@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" As of commit 660c97eef6f8 ("ivshmem: use kvm irqfd for msi notifications"), QEMU crashes with: ivshmem: msix_set_vector_notifiers failed msix_unset_vector_notifiers: Assertion `dev->msix_vector_use_notifier && de= v->msix_vector_release_notifier' failed. if MSI-X is repeatedly enabled and disabled on the ivshmem device, for exam= ple by loading and unloading the Windows ivshmem driver. This is because msix_unset_vector_notifiers() doesn't call any of the release notifier call= backs since MSI-X is already disabled at that point (msix_enabled() returning fal= se is how this transition is detected in the first place). Thus ivshmem_vector= _mask() doesn't run and when MSI-X is subsequently enabled again ivshmem_vector_unm= ask() fails. This is fixed by keeping track of unmasked vectors and making sure that ivshmem_vector_mask() always runs on MSI-X disable. Fixes: 660c97eef6f8 ("ivshmem: use kvm irqfd for msi notifications") Signed-off-by: Ladi Prosek Reviewed-by: Markus Armbruster --- hw/misc/ivshmem.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 6e46669744..91364d8364 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -77,6 +77,7 @@ typedef struct Peer { typedef struct MSIVector { PCIDevice *pdev; int virq; + bool unmasked; } MSIVector; =20 typedef struct IVShmemState { @@ -321,6 +322,7 @@ static int ivshmem_vector_unmask(PCIDevice *dev, unsign= ed vector, error_report("ivshmem: vector %d route does not exist", vector); return -EINVAL; } + assert(!v->unmasked); =20 ret =3D kvm_irqchip_update_msi_route(kvm_state, v->virq, msg, dev); if (ret < 0) { @@ -328,7 +330,13 @@ static int ivshmem_vector_unmask(PCIDevice *dev, unsig= ned vector, } kvm_irqchip_commit_routes(kvm_state); =20 - return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq); + ret =3D kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq= ); + if (ret < 0) { + return ret; + } + v->unmasked =3D true; + + return 0; } =20 static void ivshmem_vector_mask(PCIDevice *dev, unsigned vector) @@ -343,11 +351,14 @@ static void ivshmem_vector_mask(PCIDevice *dev, unsig= ned vector) error_report("ivshmem: vector %d route does not exist", vector); return; } + assert(v->unmasked); =20 ret =3D kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n, v->virq); - if (ret !=3D 0) { + if (ret < 0) { error_report("remove_irqfd_notifier_gsi failed"); + return; } + v->unmasked =3D false; } =20 static void ivshmem_vector_poll(PCIDevice *dev, @@ -817,11 +828,20 @@ static void ivshmem_disable_irqfd(IVShmemState *s) PCIDevice *pdev =3D PCI_DEVICE(s); int i; =20 - for (i =3D 0; i < s->peers[s->vm_id].nb_eventfds; i++) { - ivshmem_remove_kvm_msi_virq(s, i); - } - msix_unset_vector_notifiers(pdev); + + for (i =3D 0; i < s->peers[s->vm_id].nb_eventfds; i++) { + /* + * MSI-X is already disabled here so msix_unset_vector_notifiers() + * didn't call our release notifier. Do it now to keep our masks = and + * unmasks balanced. + */ + if (s->msi_vectors[i].unmasked) { + ivshmem_vector_mask(pdev, i); + } + ivshmem_remove_kvm_msi_virq(s, i); + } + } =20 static void ivshmem_write_config(PCIDevice *pdev, uint32_t address, --=20 2.13.6