From 22664f4115d9b297ef4276e48f8ba0bc195ec99e Mon Sep 17 00:00:00 2001 From: Zhenzhong Duan Date: Tue, 21 Nov 2023 16:44:12 +0800 Subject: [PATCH 033/101] vfio/platform: Make vfio cdev pre-openable by passing a file handle MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Eric Auger RH-MergeRequest: 211: IOMMUFD backend backport RH-Jira: RHEL-19302 RHEL-21057 RH-Acked-by: Cédric Le Goater RH-Acked-by: Sebastian Ott RH-Commit: [32/67] 069867dce64b826e92dc2051405a4ded5261981f (eauger1/centos-qemu-kvm) This gives management tools like libvirt a chance to open the vfio cdev with privilege and pass FD to qemu. This way qemu never needs to have privilege to open a VFIO or iommu cdev node. Signed-off-by: Zhenzhong Duan Reviewed-by: Cédric Le Goater Tested-by: Nicolin Chen Signed-off-by: Cédric Le Goater (cherry picked from commit 3016e60f8f715d2058a48e4956be994482c5e218) Signed-off-by: Eric Auger --- hw/vfio/platform.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c index 98ae4bc655..a97d9c6234 100644 --- a/hw/vfio/platform.c +++ b/hw/vfio/platform.c @@ -531,14 +531,13 @@ static VFIODeviceOps vfio_platform_ops = { */ static int vfio_base_device_init(VFIODevice *vbasedev, Error **errp) { - struct stat st; int ret; - /* @sysfsdev takes precedence over @host */ - if (vbasedev->sysfsdev) { + /* @fd takes precedence over @sysfsdev which takes precedence over @host */ + if (vbasedev->fd < 0 && vbasedev->sysfsdev) { g_free(vbasedev->name); vbasedev->name = g_path_get_basename(vbasedev->sysfsdev); - } else { + } else if (vbasedev->fd < 0) { if (!vbasedev->name || strchr(vbasedev->name, '/')) { error_setg(errp, "wrong host device name"); return -EINVAL; @@ -548,10 +547,9 @@ static int vfio_base_device_init(VFIODevice *vbasedev, Error **errp) vbasedev->name); } - if (stat(vbasedev->sysfsdev, &st) < 0) { - error_setg_errno(errp, errno, - "failed to get the sysfs host device file status"); - return -errno; + ret = vfio_device_get_name(vbasedev, errp); + if (ret) { + return ret; } ret = vfio_attach_device(vbasedev->name, vbasedev, @@ -658,6 +656,20 @@ static Property vfio_platform_dev_properties[] = { DEFINE_PROP_END_OF_LIST(), }; +static void vfio_platform_instance_init(Object *obj) +{ + VFIOPlatformDevice *vdev = VFIO_PLATFORM_DEVICE(obj); + + vdev->vbasedev.fd = -1; +} + +#ifdef CONFIG_IOMMUFD +static void vfio_platform_set_fd(Object *obj, const char *str, Error **errp) +{ + vfio_device_set_fd(&VFIO_PLATFORM_DEVICE(obj)->vbasedev, str, errp); +} +#endif + static void vfio_platform_class_init(ObjectClass *klass, void *data) { DeviceClass *dc = DEVICE_CLASS(klass); @@ -665,6 +677,9 @@ static void vfio_platform_class_init(ObjectClass *klass, void *data) dc->realize = vfio_platform_realize; device_class_set_props(dc, vfio_platform_dev_properties); +#ifdef CONFIG_IOMMUFD + object_class_property_add_str(klass, "fd", NULL, vfio_platform_set_fd); +#endif dc->vmsd = &vfio_platform_vmstate; dc->desc = "VFIO-based platform device assignment"; sbc->connect_irq_notifier = vfio_start_irqfd_injection; @@ -677,6 +692,7 @@ static const TypeInfo vfio_platform_dev_info = { .name = TYPE_VFIO_PLATFORM, .parent = TYPE_SYS_BUS_DEVICE, .instance_size = sizeof(VFIOPlatformDevice), + .instance_init = vfio_platform_instance_init, .class_init = vfio_platform_class_init, .class_size = sizeof(VFIOPlatformDeviceClass), }; -- 2.39.3