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Wed, 29 Nov 2023 06:38:58 -0800 From: Yishai Hadas To: , , , CC: , , , , , , , , , , Subject: [PATCH V4 vfio 9/9] vfio/virtio: Introduce a vfio driver over virtio devices Date: Wed, 29 Nov 2023 16:37:46 +0200 Message-ID: <20231129143746.6153-10-yishaih@nvidia.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20231129143746.6153-1-yishaih@nvidia.com> References: <20231129143746.6153-1-yishaih@nvidia.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-NV-OnPremToCloud: ExternallySecured X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY4PEPF0000EDD1:EE_|SJ1PR12MB6289:EE_ X-MS-Office365-Filtering-Correlation-Id: b5288521-ee6c-4d2b-fa80-08dbf0e8f67e X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:216.228.118.232;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc7edge1.nvidia.com;CAT:NONE;SFS:(13230031)(4636009)(136003)(396003)(376002)(346002)(39860400002)(230922051799003)(64100799003)(82310400011)(186009)(1800799012)(451199024)(40470700004)(46966006)(36840700001)(6666004)(7696005)(83380400001)(36860700001)(40480700001)(7636003)(36756003)(47076005)(356005)(5660300002)(4326008)(8676002)(478600001)(82740400003)(966005)(8936002)(41300700001)(70586007)(2616005)(70206006)(107886003)(54906003)(110136005)(1076003)(40460700003)(26005)(30864003)(86362001)(6636002)(316002)(336012)(426003)(2906002)(2101003);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 Nov 2023 14:39:16.0715 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: b5288521-ee6c-4d2b-fa80-08dbf0e8f67e X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.118.232];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000EDD1.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ1PR12MB6289 Introduce a vfio driver over virtio devices to support the legacy interface functionality for VFs. Background, from the virtio spec [1]. -------------------------------------------------------------------- In some systems, there is a need to support a virtio legacy driver with a device that does not directly support the legacy interface. In such scenarios, a group owner device can provide the legacy interface functionality for the group member devices. The driver of the owner device can then access the legacy interface of a member device on behalf of the legacy member device driver. For example, with the SR-IOV group type, group members (VFs) can not present the legacy interface in an I/O BAR in BAR0 as expected by the legacy pci driver. If the legacy driver is running inside a virtual machine, the hypervisor executing the virtual machine can present a virtual device with an I/O BAR in BAR0. The hypervisor intercepts the legacy driver accesses to this I/O BAR and forwards them to the group owner device (PF) using group administration commands. -------------------------------------------------------------------- Specifically, this driver adds support for a virtio-net VF to be exposed as a transitional device to a guest driver and allows the legacy IO BAR functionality on top. This allows a VM which uses a legacy virtio-net driver in the guest to work transparently over a VF which its driver in the host is that new driver. The driver can be extended easily to support some other types of virtio devices (e.g virtio-blk), by adding in a few places the specific type properties as was done for virtio-net. For now, only the virtio-net use case was tested and as such we introduce the support only for such a device. Practically, Upon probing a VF for a virtio-net device, in case its PF supports legacy access over the virtio admin commands and the VF doesn't have BAR 0, we set some specific 'vfio_device_ops' to be able to simulate in SW a transitional device with I/O BAR in BAR 0. The existence of the simulated I/O bar is reported later on by overwriting the VFIO_DEVICE_GET_REGION_INFO command and the device exposes itself as a transitional device by overwriting some properties upon reading its config space. Once we report the existence of I/O BAR as BAR 0 a legacy driver in the guest may use it via read/write calls according to the virtio specification. Any read/write towards the control parts of the BAR will be captured by the new driver and will be translated into admin commands towards the device. Any data path read/write access (i.e. virtio driver notifications) will be forwarded to the physical BAR which its properties were supplied by the admin command VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO upon the probing/init flow. With that code in place a legacy driver in the guest has the look and feel as if having a transitional device with legacy support for both its control and data path flows. [1] https://github.com/oasis-tcs/virtio-spec/commit/03c2d32e5093ca9f2a17797242fbef88efe94b8c Signed-off-by: Yishai Hadas --- MAINTAINERS | 7 + drivers/vfio/pci/Kconfig | 2 + drivers/vfio/pci/Makefile | 2 + drivers/vfio/pci/virtio/Kconfig | 16 + drivers/vfio/pci/virtio/Makefile | 4 + drivers/vfio/pci/virtio/main.c | 554 +++++++++++++++++++++++++++++++ 6 files changed, 585 insertions(+) create mode 100644 drivers/vfio/pci/virtio/Kconfig create mode 100644 drivers/vfio/pci/virtio/Makefile create mode 100644 drivers/vfio/pci/virtio/main.c diff --git a/MAINTAINERS b/MAINTAINERS index 012df8ccf34e..b246b769092d 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22872,6 +22872,13 @@ L: kvm@vger.kernel.org S: Maintained F: drivers/vfio/pci/mlx5/ +VFIO VIRTIO PCI DRIVER +M: Yishai Hadas +L: kvm@vger.kernel.org +L: virtualization@lists.linux-foundation.org +S: Maintained +F: drivers/vfio/pci/virtio + VFIO PCI DEVICE SPECIFIC DRIVERS R: Jason Gunthorpe R: Yishai Hadas diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig index 8125e5f37832..18c397df566d 100644 --- a/drivers/vfio/pci/Kconfig +++ b/drivers/vfio/pci/Kconfig @@ -65,4 +65,6 @@ source "drivers/vfio/pci/hisilicon/Kconfig" source "drivers/vfio/pci/pds/Kconfig" +source "drivers/vfio/pci/virtio/Kconfig" + endmenu diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile index 45167be462d8..046139a4eca5 100644 --- a/drivers/vfio/pci/Makefile +++ b/drivers/vfio/pci/Makefile @@ -13,3 +13,5 @@ obj-$(CONFIG_MLX5_VFIO_PCI) += mlx5/ obj-$(CONFIG_HISI_ACC_VFIO_PCI) += hisilicon/ obj-$(CONFIG_PDS_VFIO_PCI) += pds/ + +obj-$(CONFIG_VIRTIO_VFIO_PCI) += virtio/ diff --git a/drivers/vfio/pci/virtio/Kconfig b/drivers/vfio/pci/virtio/Kconfig new file mode 100644 index 000000000000..3a6707639220 --- /dev/null +++ b/drivers/vfio/pci/virtio/Kconfig @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0-only +config VIRTIO_VFIO_PCI + tristate "VFIO support for VIRTIO NET PCI devices" + depends on VIRTIO_PCI + select VFIO_PCI_CORE + help + This provides support for exposing VIRTIO NET VF devices which support + legacy IO access, using the VFIO framework that can work with a legacy + virtio driver in the guest. + Based on PCIe spec, VFs do not support I/O Space; thus, VF BARs shall + not indicate I/O Space. + As of that this driver emulated I/O BAR in software to let a VF be + seen as a transitional device in the guest and let it work with + a legacy driver. + + If you don't know what to do here, say N. diff --git a/drivers/vfio/pci/virtio/Makefile b/drivers/vfio/pci/virtio/Makefile new file mode 100644 index 000000000000..2039b39fb723 --- /dev/null +++ b/drivers/vfio/pci/virtio/Makefile @@ -0,0 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_VIRTIO_VFIO_PCI) += virtio-vfio-pci.o +virtio-vfio-pci-y := main.o + diff --git a/drivers/vfio/pci/virtio/main.c b/drivers/vfio/pci/virtio/main.c new file mode 100644 index 000000000000..3ca19c891673 --- /dev/null +++ b/drivers/vfio/pci/virtio/main.c @@ -0,0 +1,554 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct virtiovf_pci_core_device { + struct vfio_pci_core_device core_device; + u8 bar0_virtual_buf_size; + u8 *bar0_virtual_buf; + /* synchronize access to the virtual buf */ + struct mutex bar_mutex; + void __iomem *notify_addr; + u64 notify_offset; + __le32 pci_base_addr_0; + __le16 pci_cmd; + u8 notify_bar; +}; + +static int +virtiovf_issue_legacy_rw_cmd(struct virtiovf_pci_core_device *virtvdev, + loff_t pos, char __user *buf, + size_t count, bool read) +{ + bool msix_enabled = + (virtvdev->core_device.irq_type == VFIO_PCI_MSIX_IRQ_INDEX); + struct pci_dev *pdev = virtvdev->core_device.pdev; + u8 *bar0_buf = virtvdev->bar0_virtual_buf; + bool common; + u8 offset; + int ret; + + common = pos < VIRTIO_PCI_CONFIG_OFF(msix_enabled); + /* offset within the relevant configuration area */ + offset = common ? pos : pos - VIRTIO_PCI_CONFIG_OFF(msix_enabled); + mutex_lock(&virtvdev->bar_mutex); + if (read) { + if (common) + ret = virtio_pci_admin_legacy_common_io_read(pdev, offset, + count, bar0_buf + pos); + else + ret = virtio_pci_admin_legacy_device_io_read(pdev, offset, + count, bar0_buf + pos); + if (ret) + goto out; + if (copy_to_user(buf, bar0_buf + pos, count)) + ret = -EFAULT; + } else { + if (copy_from_user(bar0_buf + pos, buf, count)) { + ret = -EFAULT; + goto out; + } + + if (common) + ret = virtio_pci_admin_legacy_common_io_write(pdev, offset, + count, bar0_buf + pos); + else + ret = virtio_pci_admin_legacy_device_io_write(pdev, offset, + count, bar0_buf + pos); + } +out: + mutex_unlock(&virtvdev->bar_mutex); + return ret; +} + +static int +translate_io_bar_to_mem_bar(struct virtiovf_pci_core_device *virtvdev, + loff_t pos, char __user *buf, + size_t count, bool read) +{ + struct vfio_pci_core_device *core_device = &virtvdev->core_device; + u16 queue_notify; + int ret; + + if (pos + count > virtvdev->bar0_virtual_buf_size) + return -EINVAL; + + switch (pos) { + case VIRTIO_PCI_QUEUE_NOTIFY: + if (count != sizeof(queue_notify)) + return -EINVAL; + if (read) { + ret = vfio_pci_ioread16(core_device, true, &queue_notify, + virtvdev->notify_addr); + if (ret) + return ret; + if (copy_to_user(buf, &queue_notify, + sizeof(queue_notify))) + return -EFAULT; + } else { + if (copy_from_user(&queue_notify, buf, count)) + return -EFAULT; + ret = vfio_pci_iowrite16(core_device, true, queue_notify, + virtvdev->notify_addr); + } + break; + default: + ret = virtiovf_issue_legacy_rw_cmd(virtvdev, pos, buf, count, + read); + } + + return ret ? ret : count; +} + +static bool range_intersect_range(loff_t range1_start, size_t count1, + loff_t range2_start, size_t count2, + loff_t *start_offset, + size_t *intersect_count, + size_t *register_offset) +{ + if (range1_start <= range2_start && + range1_start + count1 > range2_start) { + *start_offset = range2_start - range1_start; + *intersect_count = min_t(size_t, count2, + range1_start + count1 - range2_start); + *register_offset = 0; + return true; + } + + if (range1_start > range2_start && + range1_start < range2_start + count2) { + *start_offset = 0; + *intersect_count = min_t(size_t, count1, + range2_start + count2 - range1_start); + *register_offset = range1_start - range2_start; + return true; + } + + return false; +} + +static ssize_t virtiovf_pci_read_config(struct vfio_device *core_vdev, + char __user *buf, size_t count, + loff_t *ppos) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; + size_t register_offset; + loff_t copy_offset; + size_t copy_count; + __le32 val32; + __le16 val16; + u8 val8; + int ret; + + ret = vfio_pci_core_read(core_vdev, buf, count, ppos); + if (ret < 0) + return ret; + + if (range_intersect_range(pos, count, PCI_DEVICE_ID, sizeof(val16), + ©_offset, ©_count, ®ister_offset)) { + val16 = cpu_to_le16(VIRTIO_TRANS_ID_NET); + if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, copy_count)) + return -EFAULT; + } + + if ((le16_to_cpu(virtvdev->pci_cmd) & PCI_COMMAND_IO) && + range_intersect_range(pos, count, PCI_COMMAND, sizeof(val16), + ©_offset, ©_count, ®ister_offset)) { + if (copy_from_user((void *)&val16 + register_offset, buf + copy_offset, + copy_count)) + return -EFAULT; + val16 |= cpu_to_le16(PCI_COMMAND_IO); + if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, + copy_count)) + return -EFAULT; + } + + if (range_intersect_range(pos, count, PCI_REVISION_ID, sizeof(val8), + ©_offset, ©_count, ®ister_offset)) { + /* Transional needs to have revision 0 */ + val8 = 0; + if (copy_to_user(buf + copy_offset, &val8, copy_count)) + return -EFAULT; + } + + if (range_intersect_range(pos, count, PCI_BASE_ADDRESS_0, sizeof(val32), + ©_offset, ©_count, ®ister_offset)) { + u8 log_bar_size = ilog2(roundup_pow_of_two(virtvdev->bar0_virtual_buf_size)); + u32 mask_size = ~((BIT(log_bar_size) - 1)); + u32 pci_base_addr_0 = le32_to_cpu(virtvdev->pci_base_addr_0); + + val32 = cpu_to_le32((pci_base_addr_0 & mask_size) | PCI_BASE_ADDRESS_SPACE_IO); + if (copy_to_user(buf + copy_offset, (void *)&val32 + register_offset, copy_count)) + return -EFAULT; + } + + if (range_intersect_range(pos, count, PCI_SUBSYSTEM_ID, sizeof(val16), + ©_offset, ©_count, ®ister_offset)) { + /* + * Transitional devices use the PCI subsystem device id as + * virtio device id, same as legacy driver always did. + */ + val16 = cpu_to_le16(VIRTIO_ID_NET); + if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, + copy_count)) + return -EFAULT; + } + + if (range_intersect_range(pos, count, PCI_SUBSYSTEM_VENDOR_ID, sizeof(val16), + ©_offset, ©_count, ®ister_offset)) { + val16 = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET); + if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, + copy_count)) + return -EFAULT; + } + + return count; +} + +static ssize_t +virtiovf_pci_core_read(struct vfio_device *core_vdev, char __user *buf, + size_t count, loff_t *ppos) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + struct pci_dev *pdev = virtvdev->core_device.pdev; + unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; + int ret; + + if (!count) + return 0; + + if (index == VFIO_PCI_CONFIG_REGION_INDEX) + return virtiovf_pci_read_config(core_vdev, buf, count, ppos); + + if (index != VFIO_PCI_BAR0_REGION_INDEX) + return vfio_pci_core_read(core_vdev, buf, count, ppos); + + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret) { + pci_info_ratelimited(pdev, "runtime resume failed %d\n", + ret); + return -EIO; + } + + ret = translate_io_bar_to_mem_bar(virtvdev, pos, buf, count, true); + pm_runtime_put(&pdev->dev); + return ret; +} + +static ssize_t +virtiovf_pci_core_write(struct vfio_device *core_vdev, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + struct pci_dev *pdev = virtvdev->core_device.pdev; + unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos); + loff_t pos = *ppos & VFIO_PCI_OFFSET_MASK; + int ret; + + if (!count) + return 0; + + if (index == VFIO_PCI_CONFIG_REGION_INDEX) { + size_t register_offset; + loff_t copy_offset; + size_t copy_count; + + if (range_intersect_range(pos, count, PCI_COMMAND, sizeof(virtvdev->pci_cmd), + ©_offset, ©_count, + ®ister_offset)) { + if (copy_from_user((void *)&virtvdev->pci_cmd + register_offset, + buf + copy_offset, + copy_count)) + return -EFAULT; + } + + if (range_intersect_range(pos, count, PCI_BASE_ADDRESS_0, + sizeof(virtvdev->pci_base_addr_0), + ©_offset, ©_count, + ®ister_offset)) { + if (copy_from_user((void *)&virtvdev->pci_base_addr_0 + register_offset, + buf + copy_offset, + copy_count)) + return -EFAULT; + } + } + + if (index != VFIO_PCI_BAR0_REGION_INDEX) + return vfio_pci_core_write(core_vdev, buf, count, ppos); + + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret) { + pci_info_ratelimited(pdev, "runtime resume failed %d\n", ret); + return -EIO; + } + + ret = translate_io_bar_to_mem_bar(virtvdev, pos, (char __user *)buf, count, false); + pm_runtime_put(&pdev->dev); + return ret; +} + +static int +virtiovf_pci_ioctl_get_region_info(struct vfio_device *core_vdev, + unsigned int cmd, unsigned long arg) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + unsigned long minsz = offsetofend(struct vfio_region_info, offset); + void __user *uarg = (void __user *)arg; + struct vfio_region_info info = {}; + + if (copy_from_user(&info, uarg, minsz)) + return -EFAULT; + + if (info.argsz < minsz) + return -EINVAL; + + switch (info.index) { + case VFIO_PCI_BAR0_REGION_INDEX: + info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index); + info.size = virtvdev->bar0_virtual_buf_size; + info.flags = VFIO_REGION_INFO_FLAG_READ | + VFIO_REGION_INFO_FLAG_WRITE; + return copy_to_user(uarg, &info, minsz) ? -EFAULT : 0; + default: + return vfio_pci_core_ioctl(core_vdev, cmd, arg); + } +} + +static long +virtiovf_vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd, + unsigned long arg) +{ + switch (cmd) { + case VFIO_DEVICE_GET_REGION_INFO: + return virtiovf_pci_ioctl_get_region_info(core_vdev, cmd, arg); + default: + return vfio_pci_core_ioctl(core_vdev, cmd, arg); + } +} + +static int +virtiovf_set_notify_addr(struct virtiovf_pci_core_device *virtvdev) +{ + struct vfio_pci_core_device *core_device = &virtvdev->core_device; + int ret; + + /* + * Setup the BAR where the 'notify' exists to be used by vfio as well + * This will let us mmap it only once and use it when needed. + */ + ret = vfio_pci_core_setup_barmap(core_device, + virtvdev->notify_bar); + if (ret) + return ret; + + virtvdev->notify_addr = core_device->barmap[virtvdev->notify_bar] + + virtvdev->notify_offset; + return 0; +} + +static int virtiovf_pci_open_device(struct vfio_device *core_vdev) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + struct vfio_pci_core_device *vdev = &virtvdev->core_device; + int ret; + + ret = vfio_pci_core_enable(vdev); + if (ret) + return ret; + + if (virtvdev->bar0_virtual_buf) { + /* + * Upon close_device() the vfio_pci_core_disable() is called + * and will close all the previous mmaps, so it seems that the + * valid life cycle for the 'notify' addr is per open/close. + */ + ret = virtiovf_set_notify_addr(virtvdev); + if (ret) { + vfio_pci_core_disable(vdev); + return ret; + } + } + + vfio_pci_core_finish_enable(vdev); + return 0; +} + +static int virtiovf_get_device_config_size(unsigned short device) +{ + /* Network card */ + return offsetofend(struct virtio_net_config, status); +} + +static int virtiovf_read_notify_info(struct virtiovf_pci_core_device *virtvdev) +{ + u64 offset; + int ret; + u8 bar; + + ret = virtio_pci_admin_legacy_io_notify_info(virtvdev->core_device.pdev, + VIRTIO_ADMIN_CMD_NOTIFY_INFO_FLAGS_OWNER_MEM, + &bar, &offset); + if (ret) + return ret; + + virtvdev->notify_bar = bar; + virtvdev->notify_offset = offset; + return 0; +} + +static int virtiovf_pci_init_device(struct vfio_device *core_vdev) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + struct pci_dev *pdev; + int ret; + + ret = vfio_pci_core_init_dev(core_vdev); + if (ret) + return ret; + + pdev = virtvdev->core_device.pdev; + ret = virtiovf_read_notify_info(virtvdev); + if (ret) + return ret; + + /* Being ready with a buffer that supports MSIX */ + virtvdev->bar0_virtual_buf_size = VIRTIO_PCI_CONFIG_OFF(true) + + virtiovf_get_device_config_size(pdev->device); + virtvdev->bar0_virtual_buf = kzalloc(virtvdev->bar0_virtual_buf_size, + GFP_KERNEL); + if (!virtvdev->bar0_virtual_buf) + return -ENOMEM; + mutex_init(&virtvdev->bar_mutex); + return 0; +} + +static void virtiovf_pci_core_release_dev(struct vfio_device *core_vdev) +{ + struct virtiovf_pci_core_device *virtvdev = container_of( + core_vdev, struct virtiovf_pci_core_device, core_device.vdev); + + kfree(virtvdev->bar0_virtual_buf); + vfio_pci_core_release_dev(core_vdev); +} + +static const struct vfio_device_ops virtiovf_vfio_pci_tran_ops = { + .name = "virtio-vfio-pci-trans", + .init = virtiovf_pci_init_device, + .release = virtiovf_pci_core_release_dev, + .open_device = virtiovf_pci_open_device, + .close_device = vfio_pci_core_close_device, + .ioctl = virtiovf_vfio_pci_core_ioctl, + .read = virtiovf_pci_core_read, + .write = virtiovf_pci_core_write, + .mmap = vfio_pci_core_mmap, + .request = vfio_pci_core_request, + .match = vfio_pci_core_match, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, +}; + +static const struct vfio_device_ops virtiovf_vfio_pci_ops = { + .name = "virtio-vfio-pci", + .init = vfio_pci_core_init_dev, + .release = vfio_pci_core_release_dev, + .open_device = virtiovf_pci_open_device, + .close_device = vfio_pci_core_close_device, + .ioctl = vfio_pci_core_ioctl, + .device_feature = vfio_pci_core_ioctl_feature, + .read = vfio_pci_core_read, + .write = vfio_pci_core_write, + .mmap = vfio_pci_core_mmap, + .request = vfio_pci_core_request, + .match = vfio_pci_core_match, + .bind_iommufd = vfio_iommufd_physical_bind, + .unbind_iommufd = vfio_iommufd_physical_unbind, + .attach_ioas = vfio_iommufd_physical_attach_ioas, +}; + +static bool virtiovf_bar0_exists(struct pci_dev *pdev) +{ + struct resource *res = pdev->resource; + + return res->flags ? true : false; +} + +static int virtiovf_pci_probe(struct pci_dev *pdev, + const struct pci_device_id *id) +{ + const struct vfio_device_ops *ops = &virtiovf_vfio_pci_ops; + struct virtiovf_pci_core_device *virtvdev; + int ret; + + if (pdev->is_virtfn && virtio_pci_admin_has_legacy_io(pdev) && + !virtiovf_bar0_exists(pdev)) + ops = &virtiovf_vfio_pci_tran_ops; + + virtvdev = vfio_alloc_device(virtiovf_pci_core_device, core_device.vdev, + &pdev->dev, ops); + if (IS_ERR(virtvdev)) + return PTR_ERR(virtvdev); + + dev_set_drvdata(&pdev->dev, &virtvdev->core_device); + ret = vfio_pci_core_register_device(&virtvdev->core_device); + if (ret) + goto out; + return 0; +out: + vfio_put_device(&virtvdev->core_device.vdev); + return ret; +} + +static void virtiovf_pci_remove(struct pci_dev *pdev) +{ + struct virtiovf_pci_core_device *virtvdev = dev_get_drvdata(&pdev->dev); + + vfio_pci_core_unregister_device(&virtvdev->core_device); + vfio_put_device(&virtvdev->core_device.vdev); +} + +static const struct pci_device_id virtiovf_pci_table[] = { + /* Only virtio-net is supported/tested so far */ + { PCI_DRIVER_OVERRIDE_DEVICE_VFIO(PCI_VENDOR_ID_REDHAT_QUMRANET, 0x1041) }, + {} +}; + +MODULE_DEVICE_TABLE(pci, virtiovf_pci_table); + +static struct pci_driver virtiovf_pci_driver = { + .name = KBUILD_MODNAME, + .id_table = virtiovf_pci_table, + .probe = virtiovf_pci_probe, + .remove = virtiovf_pci_remove, + .err_handler = &vfio_pci_core_err_handlers, + .driver_managed_dma = true, +}; + +module_pci_driver(virtiovf_pci_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Yishai Hadas "); +MODULE_DESCRIPTION( + "VIRTIO VFIO PCI - User Level meta-driver for VIRTIO NET devices");