+ * @offset: starting byte offset within the registers to write to
+ * @size: size of the data to write
+ * @buf: buffer which holds the data
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+int virtio_pci_admin_legacy_io_write(struct pci_dev *pdev, u16 opcode,
+ u8 offset, u8 size, u8 *buf)
+{
+ struct virtio_device *virtio_dev = virtio_pci_vf_get_pf_dev(pdev);
+ struct virtio_admin_cmd_legacy_wr_data *data;
+ struct virtio_admin_cmd cmd = {};
+ struct scatterlist data_sg;
+ int vf_id;
+ int ret;
+
+ if (!virtio_dev)
+ return -ENODEV;
+
+ vf_id = pci_iov_vf_id(pdev);
+ if (vf_id < 0)
+ return vf_id;
+
+ data = kzalloc(sizeof(*data) + size, GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->offset = offset;
+ memcpy(data->registers, buf, size);
+ sg_init_one(&data_sg, data, sizeof(*data) + size);
+ cmd.opcode = cpu_to_le16(opcode);
+ cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SRIOV);
+ cmd.group_member_id = cpu_to_le64(vf_id + 1);
+ cmd.data_sg = &data_sg;
+ ret = vp_modern_admin_cmd_exec(virtio_dev, &cmd);
+
+ kfree(data);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(virtio_pci_admin_legacy_io_write);
+
+/*
+ * virtio_pci_admin_legacy_io_read - Read legacy registers of a member device
+ * @dev: VF pci_dev
+ * @opcode: op code of the io read command
+ * @offset: starting byte offset within the registers to read from
+ * @size: size of the data to be read
+ * @buf: buffer to hold the returned data
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+int virtio_pci_admin_legacy_io_read(struct pci_dev *pdev, u16 opcode,
+ u8 offset, u8 size, u8 *buf)
+{
+ struct virtio_device *virtio_dev = virtio_pci_vf_get_pf_dev(pdev);
+ struct virtio_admin_cmd_legacy_rd_data *data;
+ struct scatterlist data_sg, result_sg;
+ struct virtio_admin_cmd cmd = {};
+ int vf_id;
+ int ret;
+
+ if (!virtio_dev)
+ return -ENODEV;
+
+ vf_id = pci_iov_vf_id(pdev);
+ if (vf_id < 0)
+ return vf_id;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->offset = offset;
+ sg_init_one(&data_sg, data, sizeof(*data));
+ sg_init_one(&result_sg, buf, size);
+ cmd.opcode = cpu_to_le16(opcode);
+ cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SRIOV);
+ cmd.group_member_id = cpu_to_le64(vf_id + 1);
+ cmd.data_sg = &data_sg;
+ cmd.result_sg = &result_sg;
+ ret = vp_modern_admin_cmd_exec(virtio_dev, &cmd);
+
+ kfree(data);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(virtio_pci_admin_legacy_io_read);
+
+/*
+ * virtio_pci_admin_legacy_io_notify_info - Read the queue notification
+ * information for legacy interface
+ * @dev: VF pci_dev
+ * @req_bar_flags: requested bar flags
+ * @bar: on output the BAR number of the member device
+ * @bar_offset: on output the offset within bar
+ *
+ * Returns 0 on success, or negative on failure.
+ */
+int virtio_pci_admin_legacy_io_notify_info(struct pci_dev *pdev,
+ u8 req_bar_flags, u8 *bar,
+ u64 *bar_offset)
+{
+ struct virtio_device *virtio_dev = virtio_pci_vf_get_pf_dev(pdev);
+ struct virtio_admin_cmd_notify_info_result *result;
+ struct virtio_admin_cmd cmd = {};
+ struct scatterlist result_sg;
+ int vf_id;
+ int ret;
+
+ if (!virtio_dev)
+ return -ENODEV;
+
+ vf_id = pci_iov_vf_id(pdev);
+ if (vf_id < 0)
+ return vf_id;
+
+ result = kzalloc(sizeof(*result), GFP_KERNEL);
+ if (!result)
+ return -ENOMEM;
+
+ sg_init_one(&result_sg, result, sizeof(*result));
+ cmd.opcode = cpu_to_le16(VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO);
+ cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SRIOV);
+ cmd.group_member_id = cpu_to_le64(vf_id + 1);
+ cmd.result_sg = &result_sg;
+ ret = vp_modern_admin_cmd_exec(virtio_dev, &cmd);
+ if (!ret) {
+ struct virtio_admin_cmd_notify_info_data *entry;
+ int i;
+
+ ret = -ENOENT;
+ for (i = 0; i < VIRTIO_ADMIN_CMD_MAX_NOTIFY_INFO; i++) {
+ entry = &result->entries[i];
+ if (entry->flags == VIRTIO_ADMIN_CMD_NOTIFY_INFO_FLAGS_END)
+ break;
+ if (entry->flags != req_bar_flags)
+ continue;
+ *bar = entry->bar;
+ *bar_offset = le64_to_cpu(entry->offset);
+ ret = 0;
+ break;
+ }
+ }
+
+ kfree(result);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(virtio_pci_admin_legacy_io_notify_info);
+
static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
.get = NULL,
.set = NULL,
diff --git a/include/linux/virtio_pci_admin.h b/include/linux/virtio_pci_admin.h
new file mode 100644
index 000000000000..cb916a4bc1b1
--- /dev/null
+++ b/include/linux/virtio_pci_admin.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_VIRTIO_PCI_ADMIN_H
+#define _LINUX_VIRTIO_PCI_ADMIN_H
+
+#include <linux/types.h>
+#include <linux/pci.h>
+
+int virtio_pci_admin_list_use(struct pci_dev *pdev, u8 *buf, int buf_size);
+int virtio_pci_admin_list_query(struct pci_dev *pdev, u8 *buf, int buf_size);
+int virtio_pci_admin_legacy_io_write(struct pci_dev *pdev, u16 opcode,
+ u8 offset, u8 size, u8 *buf);
+int virtio_pci_admin_legacy_io_read(struct pci_dev *pdev, u16 opcode,
+ u8 offset, u8 size, u8 *buf);
+int virtio_pci_admin_legacy_io_notify_info(struct pci_dev *pdev,
+ u8 req_bar_flags, u8 *bar,
+ u64 *bar_offset);
+
+#endif /* _LINUX_VIRTIO_PCI_ADMIN_H */
--
2.27.0
