From nobody Thu Jul 3 16:03:48 2025 Delivered-To: importer2@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1677577242; cv=none; d=zohomail.com; s=zohoarc; b=KCNf9cIr0bozRxmvzaImoEhWFyEn+OBHH5l96Ys3qY1ifmIXzlgze1rBG3OdnXEvTX7AcoaSF+UnAO7H0RLJcXQJ1hFBzR08/TU1fgYM2s5fmQ+/ch6nUvyFe5n+/EPMPXVQNwEXBYwoElU0U6FJcGN9zliO4utSXvibktbblSg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1677577242; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Reply-To:References:Sender:Subject:To; bh=bo6Vg60eQ6GecgKmQlI82TfylZAqPfN+6thoYnIiClg=; b=XkXGxqYLlPHlHFAgHiSWMYkXRnqCrdrxtxryY06v5eoZ5+WkD3Tt7W/VMHVo9b/huuK0y2/wJmd9qITfkSOagvcsUwFYZu+YVn/w43sJ1YuN/ZlzRSAlYkThBEq6KYHzIP1qz8aJEIGK1B/QTjXl25sqpJ892gTUHRPmX863/XE= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer2=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 167757724250758.12904816479465; Tue, 28 Feb 2023 01:40:42 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pWwSo-0002N3-Dx; Tue, 28 Feb 2023 04:40:02 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pWwSm-0002Kn-HO for qemu-devel@nongnu.org; Tue, 28 Feb 2023 04:40:00 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pWwSi-0003Be-CK for qemu-devel@nongnu.org; Tue, 28 Feb 2023 04:40:00 -0500 Received: from kwepemi100025.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4PQsjM4WG4z9tD0; Tue, 28 Feb 2023 17:37:43 +0800 (CST) Received: from DESKTOP-27KDQMV.china.huawei.com (10.174.148.223) by kwepemi100025.china.huawei.com (7.221.188.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Tue, 28 Feb 2023 17:39:41 +0800 To: , , CC: , , , , , , , Longpeng Subject: [PATCH v1 1/3] virtio-pci: submit msi route changes in batch Date: Tue, 28 Feb 2023 17:39:35 +0800 Message-ID: <20230228093937.2515-2-longpeng2@huawei.com> X-Mailer: git-send-email 2.25.0.windows.1 In-Reply-To: <20230228093937.2515-1-longpeng2@huawei.com> References: <20230228093937.2515-1-longpeng2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.174.148.223] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemi100025.china.huawei.com (7.221.188.158) X-CFilter-Loop: Reflected Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer2=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=45.249.212.188; envelope-from=longpeng2@huawei.com; helo=szxga02-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-to: "Longpeng(Mike)" From: "Longpeng(Mike)" via Errors-To: qemu-devel-bounces+importer2=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer2=patchew.org@nongnu.org X-ZM-MESSAGEID: 1677577243837100005 Content-Type: text/plain; charset="utf-8" From: Longpeng The kvm_irqchip_commit_routes() is a time-intensive operation, it needs scan and update all irqfds that are already assigned during each invocation, so more vectors means need more time to process them. For virtio-pci, we can just submit once when enabling vectors of a virtio-pci device. This can reduce the downtime when migrating a VM with vhost-vdpa devices. Signed-off-by: Longpeng --- hw/virtio/virtio-pci.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 247325c193..22e76e3902 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -49,6 +49,19 @@ * configuration space */ #define VIRTIO_PCI_CONFIG_SIZE(dev) VIRTIO_PCI_CONFIG_OFF(msix_enabled= (dev)) =20 +/* Protected by the BQL */ +static KVMRouteChange virtio_pci_route_change; + +static inline void virtio_pci_begin_route_changes(void) +{ + virtio_pci_route_change =3D kvm_irqchip_begin_route_changes(kvm_state); +} + +static inline void virtio_pci_commit_route_changes(void) +{ + kvm_irqchip_commit_route_changes(&virtio_pci_route_change); +} + static void virtio_pci_bus_new(VirtioBusState *bus, size_t bus_size, VirtIOPCIProxy *dev); static void virtio_pci_reset(DeviceState *qdev); @@ -790,12 +803,11 @@ static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProx= y *proxy, int ret; =20 if (irqfd->users =3D=3D 0) { - KVMRouteChange c =3D kvm_irqchip_begin_route_changes(kvm_state); - ret =3D kvm_irqchip_add_msi_route(&c, vector, &proxy->pci_dev); + ret =3D kvm_irqchip_add_msi_route(&virtio_pci_route_change, vector, + &proxy->pci_dev); if (ret < 0) { return ret; } - kvm_irqchip_commit_route_changes(&c); irqfd->virq =3D ret; } irqfd->users++; @@ -903,12 +915,18 @@ static int kvm_virtio_pci_vector_vq_use(VirtIOPCIProx= y *proxy, int nvqs) int ret =3D 0; VirtIODevice *vdev =3D virtio_bus_get_device(&proxy->bus); =20 + virtio_pci_begin_route_changes(); + for (queue_no =3D 0; queue_no < nvqs; queue_no++) { if (!virtio_queue_get_num(vdev, queue_no)) { + virtio_pci_commit_route_changes(); return -1; } ret =3D kvm_virtio_pci_vector_use_one(proxy, queue_no); } + + virtio_pci_commit_route_changes(); + return ret; } =20 --=20 2.23.0