From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50678) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eimft-0001UM-4p for qemu-devel@nongnu.org; Mon, 05 Feb 2018 14:43:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eimfp-0007v8-VO for qemu-devel@nongnu.org; Mon, 05 Feb 2018 14:43:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49560) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eimfp-0007uB-OM for qemu-devel@nongnu.org; Mon, 05 Feb 2018 14:43:29 -0500 References: <1517464293-7012-1-git-send-email-changpeng.liu@intel.com> From: Paolo Bonzini Message-ID: <883c5971-b8a6-d554-b19e-755bc8807a24@redhat.com> Date: Mon, 5 Feb 2018 20:43:17 +0100 MIME-Version: 1.0 In-Reply-To: <1517464293-7012-1-git-send-email-changpeng.liu@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] virtio-blk: enable multiple vectors when using multiple I/O queues List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Changpeng Liu , qemu-devel@nongnu.org Cc: stefanha@gmail.com, mst@redhat.com, marcandre.lureau@redhat.com, james.r.harris@intel.com On 01/02/2018 06:51, Changpeng Liu wrote: > Currently virtio-pci driver hardcoded 2 vectors for virtio-blk device, > for multiple I/O queues scenario, all the I/O queues will share one > interrupt vector, while here, enable multiple vectors according to > the number of I/O queues. > > Signed-off-by: Changpeng Liu This is a change in the device's interface to the guest ("guest ABI"), so it has to be protected with migration compatibility: just add to HW_COMPAT_2_11 in include/hw/compat.h the following: {\ .driver = "virtio-blk-pci",\ .property = "vectors",\ .value = "2",\ },\ {\ .driver = "vhost-user-blk-pci",\ .property = "vectors",\ .value = "2",\ },\ Otherwise, it looks good. Thanks, Paolo > --- > hw/virtio/virtio-pci.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 9ae10f0..379b00c 100644 > --- a/hw/virtio/virtio-pci.c > +++ b/hw/virtio/virtio-pci.c > @@ -1932,7 +1932,7 @@ static Property virtio_blk_pci_properties[] = { > DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0), > DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags, > VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true), > - DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2), > + DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, DEV_NVECTORS_UNSPECIFIED), > DEFINE_PROP_END_OF_LIST(), > }; > > @@ -1941,6 +1941,10 @@ static void virtio_blk_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp) > VirtIOBlkPCI *dev = VIRTIO_BLK_PCI(vpci_dev); > DeviceState *vdev = DEVICE(&dev->vdev); > > + if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) { > + vpci_dev->nvectors = dev->vdev.conf.num_queues + 1; > + } > + > qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus)); > object_property_set_bool(OBJECT(vdev), true, "realized", errp); > } > @@ -1983,7 +1987,7 @@ static const TypeInfo virtio_blk_pci_info = { > > static Property vhost_user_blk_pci_properties[] = { > DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0), > - DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2), > + DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, DEV_NVECTORS_UNSPECIFIED), > DEFINE_PROP_END_OF_LIST(), > }; > > @@ -1992,6 +1996,10 @@ static void vhost_user_blk_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp) > VHostUserBlkPCI *dev = VHOST_USER_BLK_PCI(vpci_dev); > DeviceState *vdev = DEVICE(&dev->vdev); > > + if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) { > + vpci_dev->nvectors = dev->vdev.num_queues + 1; > + } > + > qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus)); > object_property_set_bool(OBJECT(vdev), true, "realized", errp); > } >