Introduce APIs to execute legacy IO admin commands.
It includes: io_legacy_read/write for both common and the device
configuration, io_legacy_notify_info.
In addition, exposing an API to check whether the legacy IO commands are
supported. (i.e. virtio_pci_admin_has_legacy_io()).
Those APIs will be used by the next patches from this series.
Note:
As of some limitations in the legacy driver (e.g. lack of memory
barriers in ARM, endian-ness is broken in PPC) the
virtio_pci_admin_has_legacy_io() returns false on non X86 systems.
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Yishai Hadas <yishaih@xxxxxxxxxx>
---
drivers/virtio/virtio_pci_common.c | 11 ++
drivers/virtio/virtio_pci_common.h | 2 +
drivers/virtio/virtio_pci_modern.c | 252 +++++++++++++++++++++++++++++
include/linux/virtio_pci_admin.h | 21 +++
4 files changed, 286 insertions(+)
create mode 100644 include/linux/virtio_pci_admin.h
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index fafd13d0e4d4..9f93330fc2cc 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -645,6 +645,17 @@ static struct pci_driver virtio_pci_driver = {
.sriov_configure = virtio_pci_sriov_configure,
};
+struct virtio_device *virtio_pci_vf_get_pf_dev(struct pci_dev *pdev)
+{
+ struct virtio_pci_device *pf_vp_dev;
+
+ pf_vp_dev = pci_iov_get_pf_drvdata(pdev, &virtio_pci_driver);
+ if (IS_ERR(pf_vp_dev))
+ return NULL;
+
+ return &pf_vp_dev->vdev;
+}
+
module_pci_driver(virtio_pci_driver);
MODULE_AUTHOR("Anthony Liguori <aliguori@xxxxxxxxxx>");
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index 2e3ae417519d..af676b3b9907 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -156,4 +156,6 @@ static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
int virtio_pci_modern_probe(struct virtio_pci_device *);
void virtio_pci_modern_remove(struct virtio_pci_device *);
+struct virtio_device *virtio_pci_vf_get_pf_dev(struct pci_dev *pdev);
+
#endif
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 951014dbb086..53e29824d404 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -15,6 +15,7 @@
*/
#include <linux/delay.h>
+#include <linux/virtio_pci_admin.h>
#define VIRTIO_PCI_NO_LEGACY
#define VIRTIO_RING_NO_LEGACY
#include "virtio_pci_common.h"
@@ -774,6 +775,257 @@ static void vp_modern_destroy_avq(struct virtio_device *vdev)
vp_dev->del_vq(&vp_dev->admin_vq.info);
}
+#define VIRTIO_LEGACY_ADMIN_CMD_BITMAP \
+ (BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE) | \
+ BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ) | \
+ BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE) | \
+ BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ) | \
+ BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO))
+
+#ifdef CONFIG_X86
+/*
+ * virtio_pci_admin_has_legacy_io - Checks whether the legacy IO
+ * commands are supported
+ * @dev: VF pci_dev
+ *
+ * Returns true on success.
+ */
+bool virtio_pci_admin_has_legacy_io(struct pci_dev *pdev)
+{
+ struct virtio_device *virtio_dev = virtio_pci_vf_get_pf_dev(pdev);
+ struct virtio_pci_device *vp_dev;
+
+ if (!virtio_dev)
+ return false;
+
+ if (!virtio_has_feature(virtio_dev, VIRTIO_F_ADMIN_VQ))
+ return false;
+
+ vp_dev = to_vp_device(virtio_dev);
+
+ if ((vp_dev->admin_vq.supported_cmds & VIRTIO_LEGACY_ADMIN_CMD_BITMAP) ==
+ VIRTIO_LEGACY_ADMIN_CMD_BITMAP)
+ return true;
+ return false;
+}
+#else
+bool virtio_pci_admin_has_legacy_io(struct pci_dev *pdev)
+{
+ return false;
+}
+#endif
+EXPORT_SYMBOL_GPL(virtio_pci_admin_has_legacy_io);
+
+static 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;
+}
+
+/*
+ * virtio_pci_admin_legacy_io_write_common - Write legacy common configuration
+ * of a member device
+ * @dev: VF pci_dev
+ * @offset: starting byte offset within the common configuration area to write to
+ * @size: size of the data to write
+ * @buf: buffer which holds the data
+ *
+ * Note: caller must serialize access for the given device.
+ * Returns 0 on success, or negative on failure.
+ */
+int virtio_pci_admin_legacy_common_io_write(struct pci_dev *pdev, u8 offset,
+ u8 size, u8 *buf)
+{
+ return virtio_pci_admin_legacy_io_write(pdev,
+ VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE,
+ offset, size, buf);
+}
+EXPORT_SYMBOL_GPL(virtio_pci_admin_legacy_common_io_write);
+
+/*
+ * virtio_pci_admin_legacy_io_write_device - Write legacy device configuration
+ * of a member device
+ * @dev: VF pci_dev
+ * @offset: starting byte offset within the device configuration area to write to
+ * @size: size of the data to write
+ * @buf: buffer which holds the data
+ *
+ * Note: caller must serialize access for the given device.
+ * Returns 0 on success, or negative on failure.
+ */
+int virtio_pci_admin_legacy_device_io_write(struct pci_dev *pdev, u8 offset,
+ u8 size, u8 *buf)
+{
+ return virtio_pci_admin_legacy_io_write(pdev,
+ VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE,
+ offset, size, buf);
+}
+EXPORT_SYMBOL_GPL(virtio_pci_admin_legacy_device_io_write);
+
+static 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;
+}
+
+/*
+ * virtio_pci_admin_legacy_device_io_read - Read legacy device configuration of
+ * a member device
+ * @dev: VF pci_dev
+ * @offset: starting byte offset within the device configuration area to read from
+ * @size: size of the data to be read
+ * @buf: buffer to hold the returned data
+ *
+ * Note: caller must serialize access for the given device.
+ * Returns 0 on success, or negative on failure.
+ */
+int virtio_pci_admin_legacy_device_io_read(struct pci_dev *pdev, u8 offset,
+ u8 size, u8 *buf)
+{
+ return virtio_pci_admin_legacy_io_read(pdev,
+ VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ,
+ offset, size, buf);
+}
+EXPORT_SYMBOL_GPL(virtio_pci_admin_legacy_device_io_read);
+
+/*
+ * virtio_pci_admin_legacy_common_io_read - Read legacy common configuration of
+ * a member device
+ * @dev: VF pci_dev
+ * @offset: starting byte offset within the common configuration area to read from
+ * @size: size of the data to be read
+ * @buf: buffer to hold the returned data
+ *
+ * Note: caller must serialize access for the given device.
+ * Returns 0 on success, or negative on failure.
+ */
+int virtio_pci_admin_legacy_common_io_read(struct pci_dev *pdev, u8 offset,
+ u8 size, u8 *buf)
+{
+ return virtio_pci_admin_legacy_io_read(pdev,
+ VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ,
+ offset, size, buf);
+}
+EXPORT_SYMBOL_GPL(virtio_pci_admin_legacy_common_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 owner or 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..446ced8cb050
--- /dev/null
+++ b/include/linux/virtio_pci_admin.h
@@ -0,0 +1,21 @@
+/* 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>
+
+bool virtio_pci_admin_has_legacy_io(struct pci_dev *pdev);
+int virtio_pci_admin_legacy_common_io_write(struct pci_dev *pdev, u8 offset,
+ u8 size, u8 *buf);
+int virtio_pci_admin_legacy_common_io_read(struct pci_dev *pdev, u8 offset,
+ u8 size, u8 *buf);
+int virtio_pci_admin_legacy_device_io_write(struct pci_dev *pdev, u8 offset,
+ u8 size, u8 *buf);
+int virtio_pci_admin_legacy_device_io_read(struct pci_dev *pdev, 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
