From patchwork Fri Sep 9 21:47:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 9324479 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 22C3860752 for ; Fri, 9 Sep 2016 21:52:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1163B2A007 for ; Fri, 9 Sep 2016 21:52:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 061C92A024; Fri, 9 Sep 2016 21:52:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7695D2A007 for ; Fri, 9 Sep 2016 21:52:39 +0000 (UTC) Received: from localhost ([::1]:60431 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1biTiw-0008E7-M6 for patchwork-qemu-devel@patchwork.kernel.org; Fri, 09 Sep 2016 17:52:38 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40293) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1biTdz-00048Z-6r for qemu-devel@nongnu.org; Fri, 09 Sep 2016 17:47:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1biTdy-0004O0-0o for qemu-devel@nongnu.org; Fri, 09 Sep 2016 17:47:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48638) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1biTdx-0004Nv-Ov for qemu-devel@nongnu.org; Fri, 09 Sep 2016 17:47:29 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 566F97F368; Fri, 9 Sep 2016 21:47:29 +0000 (UTC) Received: from redhat.com (vpn-62-83.rdu2.redhat.com [10.10.62.83]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id u89LlSdx002534; Fri, 9 Sep 2016 17:47:28 -0400 Date: Sat, 10 Sep 2016 00:47:28 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <1473456998-14863-6-git-send-email-mst@redhat.com> References: <1473456998-14863-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1473456998-14863-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 09 Sep 2016 21:47:29 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v2 05/14] virtio-pci: reduce modern_mem_bar size 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: Marcel Apfelbaum , Peter Maydell Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Marcel Apfelbaum Currently each VQ Notification Virtio Capability is allocated on a different page. The idea is to enable split drivers within guests, however there are no known plans to do that. The allocation will result in a 8MB BAR, more than various guest firmwares pre-allocates for PCI Bridges hotplug process. Reserve 4 bytes per VQ by default and add a new parameter "page-per-vq" to be used with split drivers. Signed-off-by: Marcel Apfelbaum Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio-pci.h | 5 +++++ include/hw/compat.h | 6 +++++- hw/virtio/virtio-pci.c | 22 +++++++++++++++------- 3 files changed, 25 insertions(+), 8 deletions(-) diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h index 25fbf8a..a745512 100644 --- a/hw/virtio/virtio-pci.h +++ b/hw/virtio/virtio-pci.h @@ -64,6 +64,7 @@ enum { VIRTIO_PCI_FLAG_MIGRATE_EXTRA_BIT, VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT, VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT, + VIRTIO_PCI_FLAG_PAGE_PER_VQ_BIT, }; /* Need to activate work-arounds for buggy guests at vmstate load. */ @@ -84,6 +85,10 @@ enum { #define VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY \ (1 << VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT) +/* page per vq flag to be used by split drivers within guests */ +#define VIRTIO_PCI_FLAG_PAGE_PER_VQ \ + (1 << VIRTIO_PCI_FLAG_PAGE_PER_VQ_BIT) + typedef struct { MSIMessage msg; int virq; diff --git a/include/hw/compat.h b/include/hw/compat.h index 08dd4fb..a1d6694 100644 --- a/include/hw/compat.h +++ b/include/hw/compat.h @@ -2,7 +2,11 @@ #define HW_COMPAT_H #define HW_COMPAT_2_7 \ - /* empty */ + {\ + .driver = "virtio-pci",\ + .property = "page-per-vq",\ + .value = "on",\ + }, #define HW_COMPAT_2_6 \ {\ diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 268fd8e..89bc196 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -294,6 +294,12 @@ static void virtio_pci_ioeventfd_set_disabled(DeviceState *d, bool disabled) #define QEMU_VIRTIO_PCI_QUEUE_MEM_MULT 0x1000 +static inline int virtio_pci_queue_mem_mult(struct VirtIOPCIProxy *proxy) +{ + return (proxy->flags & VIRTIO_PCI_FLAG_PAGE_PER_VQ) ? + QEMU_VIRTIO_PCI_QUEUE_MEM_MULT : 4; +} + static int virtio_pci_ioeventfd_assign(DeviceState *d, EventNotifier *notifier, int n, bool assign) { @@ -307,7 +313,7 @@ static int virtio_pci_ioeventfd_assign(DeviceState *d, EventNotifier *notifier, MemoryRegion *modern_mr = &proxy->notify.mr; MemoryRegion *modern_notify_mr = &proxy->notify_pio.mr; MemoryRegion *legacy_mr = &proxy->bar; - hwaddr modern_addr = QEMU_VIRTIO_PCI_QUEUE_MEM_MULT * + hwaddr modern_addr = virtio_pci_queue_mem_mult(proxy) * virtio_get_queue_index(vq); hwaddr legacy_addr = VIRTIO_PCI_QUEUE_NOTIFY; @@ -1370,7 +1376,8 @@ static void virtio_pci_notify_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) { VirtIODevice *vdev = opaque; - unsigned queue = addr / QEMU_VIRTIO_PCI_QUEUE_MEM_MULT; + VirtIOPCIProxy *proxy = VIRTIO_PCI(DEVICE(vdev)->parent_bus->parent); + unsigned queue = addr / virtio_pci_queue_mem_mult(proxy); if (queue < VIRTIO_QUEUE_MAX) { virtio_queue_notify(vdev, queue); @@ -1609,7 +1616,7 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) struct virtio_pci_notify_cap notify = { .cap.cap_len = sizeof notify, .notify_off_multiplier = - cpu_to_le32(QEMU_VIRTIO_PCI_QUEUE_MEM_MULT), + cpu_to_le32(virtio_pci_queue_mem_mult(proxy)), }; struct virtio_pci_cfg_cap cfg = { .cap.cap_len = sizeof cfg, @@ -1744,8 +1751,7 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp) proxy->device.type = VIRTIO_PCI_CAP_DEVICE_CFG; proxy->notify.offset = 0x3000; - proxy->notify.size = - QEMU_VIRTIO_PCI_QUEUE_MEM_MULT * VIRTIO_QUEUE_MAX; + proxy->notify.size = virtio_pci_queue_mem_mult(proxy) * VIRTIO_QUEUE_MAX; proxy->notify.type = VIRTIO_PCI_CAP_NOTIFY_CFG; proxy->notify_pio.offset = 0x0; @@ -1754,8 +1760,8 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp) /* subclasses can enforce modern, so do this unconditionally */ memory_region_init(&proxy->modern_bar, OBJECT(proxy), "virtio-pci", - 2 * QEMU_VIRTIO_PCI_QUEUE_MEM_MULT * - VIRTIO_QUEUE_MAX); + /* PCI BAR regions must be powers of 2 */ + pow2ceil(proxy->notify.offset + proxy->notify.size)); memory_region_init_alias(&proxy->modern_cfg, OBJECT(proxy), @@ -1833,6 +1839,8 @@ static Property virtio_pci_properties[] = { VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT, false), DEFINE_PROP_BIT("x-disable-pcie", VirtIOPCIProxy, flags, VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT, false), + DEFINE_PROP_BIT("page-per-vq", VirtIOPCIProxy, flags, + VIRTIO_PCI_FLAG_PAGE_PER_VQ_BIT, false), DEFINE_PROP_END_OF_LIST(), };