From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35686) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1er8cU-0004Ke-B2 for qemu-devel@nongnu.org; Wed, 28 Feb 2018 15:46:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1er8cR-0003zR-8q for qemu-devel@nongnu.org; Wed, 28 Feb 2018 15:46:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51664) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1er8cQ-0003ys-Vx for qemu-devel@nongnu.org; Wed, 28 Feb 2018 15:46:31 -0500 From: Alex Williamson Date: Wed, 28 Feb 2018 13:46:20 -0700 Message-ID: <20180228204620.26629.74688.stgit@gimli.home> In-Reply-To: <20180228201837.26629.3346.stgit@gimli.home> References: <20180228201837.26629.3346.stgit@gimli.home> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PATCH 5/5] vfio/quirks: Enable ioeventfd quirks to be handled by vfio directly List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, alex.williamson@redhat.com, peterx@redhat.com, eric.auger@redhat.com With vfio ioeventfd support, we can program vfio-pci to perform a specified BAR write when an eventfd is triggered. This allows the KVM ioeventfd to be wired directly to vfio-pci, entirely avoiding userspace handling for these events. On the same micro-benchmark where the ioeventfd got us to almost 90% of performance versus disabling the GeForce quirks, this gets us to within 95%. Signed-off-by: Alex Williamson --- hw/vfio/pci-quirks.c | 45 +++++++++++++++++++++++++++++++++++++++------ hw/vfio/pci.h | 1 + 2 files changed, 40 insertions(+), 6 deletions(-) diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c index e01e2f0f69df..561fa6ea321d 100644 --- a/hw/vfio/pci-quirks.c +++ b/hw/vfio/pci-quirks.c @@ -16,6 +16,7 @@ #include "qemu/range.h" #include "qapi/error.h" #include "qapi/visitor.h" +#include #include "hw/nvram/fw_cfg.h" #include "pci.h" #include "trace.h" @@ -287,13 +288,31 @@ static VFIOQuirk *vfio_quirk_alloc(int nr_mem) return quirk; } -static void vfio_ioeventfd_exit(VFIOIOEventFD *ioeventfd) +static void vfio_ioeventfd_exit(VFIOPCIDevice *vdev, VFIOIOEventFD *ioeventfd) { QLIST_REMOVE(ioeventfd, next); + memory_region_del_eventfd(ioeventfd->mr, ioeventfd->addr, ioeventfd->size, ioeventfd->match_data, ioeventfd->data, &ioeventfd->e); - qemu_set_fd_handler(event_notifier_get_fd(&ioeventfd->e), NULL, NULL, NULL); + + if (ioeventfd->vfio) { + struct vfio_device_ioeventfd vfio_ioeventfd; + + vfio_ioeventfd.argsz = sizeof(vfio_ioeventfd); + vfio_ioeventfd.flags = ioeventfd->size; + vfio_ioeventfd.data = ioeventfd->data; + vfio_ioeventfd.offset = ioeventfd->region->fd_offset + + ioeventfd->region_addr; + vfio_ioeventfd.fd = -1; + + ioctl(vdev->vbasedev.fd, VFIO_DEVICE_IOEVENTFD, &vfio_ioeventfd); + + } else { + qemu_set_fd_handler(event_notifier_get_fd(&ioeventfd->e), + NULL, NULL, NULL); + } + event_notifier_cleanup(&ioeventfd->e); g_free(ioeventfd); } @@ -304,7 +323,7 @@ static void vfio_drop_dynamic_eventfds(VFIOPCIDevice *vdev, VFIOQuirk *quirk) QLIST_FOREACH_SAFE(ioeventfd, &quirk->ioeventfds, next, tmp) { if (ioeventfd->dynamic) { - vfio_ioeventfd_exit(ioeventfd); + vfio_ioeventfd_exit(vdev, ioeventfd); } } } @@ -326,6 +345,7 @@ static VFIOIOEventFD *vfio_ioeventfd_init(VFIOPCIDevice *vdev, hwaddr region_addr, bool dynamic) { VFIOIOEventFD *ioeventfd = g_malloc0(sizeof(*ioeventfd)); + struct vfio_device_ioeventfd vfio_ioeventfd; if (event_notifier_init(&ioeventfd->e, 0)) { g_free(ioeventfd); @@ -349,8 +369,21 @@ static VFIOIOEventFD *vfio_ioeventfd_init(VFIOPCIDevice *vdev, ioeventfd->region = region; ioeventfd->region_addr = region_addr; - qemu_set_fd_handler(event_notifier_get_fd(&ioeventfd->e), - vfio_ioeventfd_handler, NULL, ioeventfd); + vfio_ioeventfd.argsz = sizeof(vfio_ioeventfd); + vfio_ioeventfd.flags = ioeventfd->size; + vfio_ioeventfd.data = ioeventfd->data; + vfio_ioeventfd.offset = ioeventfd->region->fd_offset + + ioeventfd->region_addr; + vfio_ioeventfd.fd = event_notifier_get_fd(&ioeventfd->e); + + ioeventfd->vfio = !ioctl(vdev->vbasedev.fd, + VFIO_DEVICE_IOEVENTFD, &vfio_ioeventfd); + + if (!ioeventfd->vfio) { + qemu_set_fd_handler(event_notifier_get_fd(&ioeventfd->e), + vfio_ioeventfd_handler, NULL, ioeventfd); + } + memory_region_add_eventfd(ioeventfd->mr, ioeventfd->addr, ioeventfd->size, ioeventfd->match_data, ioeventfd->data, &ioeventfd->e); @@ -1820,7 +1853,7 @@ void vfio_bar_quirk_exit(VFIOPCIDevice *vdev, int nr) QLIST_FOREACH(quirk, &bar->quirks, next) { while (!QLIST_EMPTY(&quirk->ioeventfds)) { - vfio_ioeventfd_exit(QLIST_FIRST(&quirk->ioeventfds)); + vfio_ioeventfd_exit(vdev, QLIST_FIRST(&quirk->ioeventfds)); } for (i = 0; i < quirk->nr_mem; i++) { diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h index de651993b57a..26c06e92ec26 100644 --- a/hw/vfio/pci.h +++ b/hw/vfio/pci.h @@ -35,6 +35,7 @@ typedef struct VFIOIOEventFD { hwaddr region_addr; bool match_data; bool dynamic; + bool vfio; } VFIOIOEventFD; typedef struct VFIOQuirk {