thr3ads.net - Virtualization - [PATCH vfio 10/11] vfio/virtio: Expose admin commands over virtio device [Sep 2023]

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Michael S. Tsirkin

2023-Sep-22 09:54 UTC

[PATCH vfio 10/11] vfio/virtio: Expose admin commands over virtio device

On Thu, Sep 21, 2023 at 03:40:39PM +0300, Yishai Hadas
wrote:> Expose admin commands over the virtio device, to be used by the
> vfio-virtio driver in the next patches.
> 
> It includes: list query/use, legacy write/read, read notify_info.
> 
> Signed-off-by: Yishai Hadas <yishaih at nvidia.com>

This stuff is pure virtio spec. I think it should live under
drivers/virtio, too.
> ---
>  drivers/vfio/pci/virtio/cmd.c | 146 ++++++++++++++++++++++++++++++++++
>  drivers/vfio/pci/virtio/cmd.h |  27 +++++++
>  2 files changed, 173 insertions(+)
>  create mode 100644 drivers/vfio/pci/virtio/cmd.c
>  create mode 100644 drivers/vfio/pci/virtio/cmd.h
> 
> diff --git a/drivers/vfio/pci/virtio/cmd.c b/drivers/vfio/pci/virtio/cmd.c
> new file mode 100644
> index 000000000000..f068239cdbb0
> --- /dev/null
> +++ b/drivers/vfio/pci/virtio/cmd.c
> @@ -0,0 +1,146 @@
> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
> +/*
> + * Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights
reserved
> + */
> +
> +#include "cmd.h"
> +
> +int virtiovf_cmd_list_query(struct pci_dev *pdev, u8 *buf, int buf_size)
> +{
> +	struct virtio_device *virtio_dev = virtio_pci_vf_get_pf_dev(pdev);
> +	struct scatterlist out_sg;
> +	struct virtio_admin_cmd cmd = {};
> +
> +	if (!virtio_dev)
> +		return -ENOTCONN;
> +
> +	sg_init_one(&out_sg, buf, buf_size);
> +	cmd.opcode = VIRTIO_ADMIN_CMD_LIST_QUERY;
> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
> +	cmd.result_sg = &out_sg;
> +
> +	return virtio_admin_cmd_exec(virtio_dev, &cmd);
> +}
> +
> +int virtiovf_cmd_list_use(struct pci_dev *pdev, u8 *buf, int buf_size)
> +{
> +	struct virtio_device *virtio_dev = virtio_pci_vf_get_pf_dev(pdev);
> +	struct scatterlist in_sg;
> +	struct virtio_admin_cmd cmd = {};
> +
> +	if (!virtio_dev)
> +		return -ENOTCONN;
> +
> +	sg_init_one(&in_sg, buf, buf_size);
> +	cmd.opcode = VIRTIO_ADMIN_CMD_LIST_USE;
> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
> +	cmd.data_sg = &in_sg;
> +
> +	return virtio_admin_cmd_exec(virtio_dev, &cmd);
> +}
> +
> +int virtiovf_cmd_lr_write(struct virtiovf_pci_core_device *virtvdev, u16
opcode,
> +			  u8 offset, u8 size, u8 *buf)
> +{
> +	struct virtio_device *virtio_dev > +	
virtio_pci_vf_get_pf_dev(virtvdev->core_device.pdev);
> +	struct virtio_admin_cmd_data_lr_write *in;
> +	struct scatterlist in_sg;
> +	struct virtio_admin_cmd cmd = {};
> +	int ret;
> +
> +	if (!virtio_dev)
> +		return -ENOTCONN;
> +
> +	in = kzalloc(sizeof(*in) + size, GFP_KERNEL);
> +	if (!in)
> +		return -ENOMEM;
> +
> +	in->offset = offset;
> +	memcpy(in->registers, buf, size);
> +	sg_init_one(&in_sg, in, sizeof(*in) + size);
> +	cmd.opcode = opcode;
> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
> +	cmd.group_member_id = virtvdev->vf_id + 1;
> +	cmd.data_sg = &in_sg;
> +	ret = virtio_admin_cmd_exec(virtio_dev, &cmd);
> +
> +	kfree(in);
> +	return ret;
> +}
> +
> +int virtiovf_cmd_lr_read(struct virtiovf_pci_core_device *virtvdev, u16
opcode,
> +			 u8 offset, u8 size, u8 *buf)
> +{
> +	struct virtio_device *virtio_dev > +	
virtio_pci_vf_get_pf_dev(virtvdev->core_device.pdev);
> +	struct virtio_admin_cmd_data_lr_read *in;
> +	struct scatterlist in_sg, out_sg;
> +	struct virtio_admin_cmd cmd = {};
> +	int ret;
> +
> +	if (!virtio_dev)
> +		return -ENOTCONN;
> +
> +	in = kzalloc(sizeof(*in), GFP_KERNEL);
> +	if (!in)
> +		return -ENOMEM;
> +
> +	in->offset = offset;
> +	sg_init_one(&in_sg, in, sizeof(*in));
> +	sg_init_one(&out_sg, buf, size);
> +	cmd.opcode = opcode;
> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
> +	cmd.data_sg = &in_sg;
> +	cmd.result_sg = &out_sg;
> +	cmd.group_member_id = virtvdev->vf_id + 1;
> +	ret = virtio_admin_cmd_exec(virtio_dev, &cmd);
> +
> +	kfree(in);
> +	return ret;
> +}
> +
> +int virtiovf_cmd_lq_read_notify(struct virtiovf_pci_core_device *virtvdev,
> +				u8 req_bar_flags, u8 *bar, u64 *bar_offset)
> +{
> +	struct virtio_device *virtio_dev > +	
virtio_pci_vf_get_pf_dev(virtvdev->core_device.pdev);
> +	struct virtio_admin_cmd_notify_info_result *out;
> +	struct scatterlist out_sg;
> +	struct virtio_admin_cmd cmd = {};
> +	int ret;
> +
> +	if (!virtio_dev)
> +		return -ENOTCONN;
> +
> +	out = kzalloc(sizeof(*out), GFP_KERNEL);
> +	if (!out)
> +		return -ENOMEM;
> +
> +	sg_init_one(&out_sg, out, sizeof(*out));
> +	cmd.opcode = VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO;
> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
> +	cmd.result_sg = &out_sg;
> +	cmd.group_member_id = virtvdev->vf_id + 1;
> +	ret = virtio_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 = &out->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(out);
> +	return ret;
> +}
> diff --git a/drivers/vfio/pci/virtio/cmd.h b/drivers/vfio/pci/virtio/cmd.h
> new file mode 100644
> index 000000000000..c2a3645f4b90
> --- /dev/null
> +++ b/drivers/vfio/pci/virtio/cmd.h
> @@ -0,0 +1,27 @@
> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
> +/*
> + * Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights
reserved.
> + */
> +
> +#ifndef VIRTIO_VFIO_CMD_H
> +#define VIRTIO_VFIO_CMD_H
> +
> +#include <linux/kernel.h>
> +#include <linux/virtio.h>
> +#include <linux/vfio_pci_core.h>
> +#include <linux/virtio_pci.h>
> +
> +struct virtiovf_pci_core_device {
> +	struct vfio_pci_core_device core_device;
> +	int vf_id;
> +};
> +
> +int virtiovf_cmd_list_query(struct pci_dev *pdev, u8 *buf, int buf_size);
> +int virtiovf_cmd_list_use(struct pci_dev *pdev, u8 *buf, int buf_size);
> +int virtiovf_cmd_lr_write(struct virtiovf_pci_core_device *virtvdev, u16
opcode,
> +			  u8 offset, u8 size, u8 *buf);
> +int virtiovf_cmd_lr_read(struct virtiovf_pci_core_device *virtvdev, u16
opcode,
> +			 u8 offset, u8 size, u8 *buf);
> +int virtiovf_cmd_lq_read_notify(struct virtiovf_pci_core_device *virtvdev,
> +				u8 req_bar_flags, u8 *bar, u64 *bar_offset);
> +#endif /* VIRTIO_VFIO_CMD_H */
> -- 
> 2.27.0

Yishai Hadas

2023-Sep-26 11:14 UTC

head link

[PATCH vfio 10/11] vfio/virtio: Expose admin commands over virtio device

On 22/09/2023 12:54, Michael S. Tsirkin wrote:> On Thu, Sep 21, 2023 at 03:40:39PM +0300, Yishai Hadas wrote:
>> Expose admin commands over the virtio device, to be used by the
>> vfio-virtio driver in the next patches.
>>
>> It includes: list query/use, legacy write/read, read notify_info.
>>
>> Signed-off-by: Yishai Hadas <yishaih at nvidia.com>
>
> This stuff is pure virtio spec. I think it should live under
> drivers/virtio, too.
The motivation to put it in the vfio layer was from the below main reasons:

1) Having it inside virtio may require to export a symbol/function per 
command.

 ?? This will end up today by 5 and in the future (e.g. live migration) 
with much more exported symbols.

 ?? With current code we export only 2 generic symbols 
virtio_pci_vf_get_pf_dev(), virtio_admin_cmd_exec() which may fit for 
any further extension.

2) For now there is no logic in this vfio layer, however, in the future 
we may have some DMA/other logic that should better fit to the 
caller/client layer (i.e. vfio).

By the way, this follows what was done already between vfio/mlx5 to 
mlx5_core modules where mlx5_core exposes generic APIs to execute a 
command and to get the a PF from a given mlx5 VF.

This way, we can enable further commands to be added/extended 
easily/cleanly.

See for example here [1, 2].

[1] 
https://elixir.bootlin.com/linux/v6.6-rc3/source/drivers/vfio/pci/mlx5/cmd.c#L210

[2] 
https://elixir.bootlin.com/linux/v6.6-rc3/source/drivers/vfio/pci/mlx5/cmd.c#L683

Yishai
>
>> ---
>>   drivers/vfio/pci/virtio/cmd.c | 146
++++++++++++++++++++++++++++++++++
>>   drivers/vfio/pci/virtio/cmd.h |  27 +++++++
>>   2 files changed, 173 insertions(+)
>>   create mode 100644 drivers/vfio/pci/virtio/cmd.c
>>   create mode 100644 drivers/vfio/pci/virtio/cmd.h
>>
>> diff --git a/drivers/vfio/pci/virtio/cmd.c
b/drivers/vfio/pci/virtio/cmd.c
>> new file mode 100644
>> index 000000000000..f068239cdbb0
>> --- /dev/null
>> +++ b/drivers/vfio/pci/virtio/cmd.c
>> @@ -0,0 +1,146 @@
>> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
>> +/*
>> + * Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights
reserved
>> + */
>> +
>> +#include "cmd.h"
>> +
>> +int virtiovf_cmd_list_query(struct pci_dev *pdev, u8 *buf, int
buf_size)
>> +{
>> +	struct virtio_device *virtio_dev = virtio_pci_vf_get_pf_dev(pdev);
>> +	struct scatterlist out_sg;
>> +	struct virtio_admin_cmd cmd = {};
>> +
>> +	if (!virtio_dev)
>> +		return -ENOTCONN;
>> +
>> +	sg_init_one(&out_sg, buf, buf_size);
>> +	cmd.opcode = VIRTIO_ADMIN_CMD_LIST_QUERY;
>> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
>> +	cmd.result_sg = &out_sg;
>> +
>> +	return virtio_admin_cmd_exec(virtio_dev, &cmd);
>> +}
>> +
>> +int virtiovf_cmd_list_use(struct pci_dev *pdev, u8 *buf, int buf_size)
>> +{
>> +	struct virtio_device *virtio_dev = virtio_pci_vf_get_pf_dev(pdev);
>> +	struct scatterlist in_sg;
>> +	struct virtio_admin_cmd cmd = {};
>> +
>> +	if (!virtio_dev)
>> +		return -ENOTCONN;
>> +
>> +	sg_init_one(&in_sg, buf, buf_size);
>> +	cmd.opcode = VIRTIO_ADMIN_CMD_LIST_USE;
>> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
>> +	cmd.data_sg = &in_sg;
>> +
>> +	return virtio_admin_cmd_exec(virtio_dev, &cmd);
>> +}
>> +
>> +int virtiovf_cmd_lr_write(struct virtiovf_pci_core_device *virtvdev,
u16 opcode,
>> +			  u8 offset, u8 size, u8 *buf)
>> +{
>> +	struct virtio_device *virtio_dev >> +	
virtio_pci_vf_get_pf_dev(virtvdev->core_device.pdev);
>> +	struct virtio_admin_cmd_data_lr_write *in;
>> +	struct scatterlist in_sg;
>> +	struct virtio_admin_cmd cmd = {};
>> +	int ret;
>> +
>> +	if (!virtio_dev)
>> +		return -ENOTCONN;
>> +
>> +	in = kzalloc(sizeof(*in) + size, GFP_KERNEL);
>> +	if (!in)
>> +		return -ENOMEM;
>> +
>> +	in->offset = offset;
>> +	memcpy(in->registers, buf, size);
>> +	sg_init_one(&in_sg, in, sizeof(*in) + size);
>> +	cmd.opcode = opcode;
>> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
>> +	cmd.group_member_id = virtvdev->vf_id + 1;
>> +	cmd.data_sg = &in_sg;
>> +	ret = virtio_admin_cmd_exec(virtio_dev, &cmd);
>> +
>> +	kfree(in);
>> +	return ret;
>> +}
>> +
>> +int virtiovf_cmd_lr_read(struct virtiovf_pci_core_device *virtvdev,
u16 opcode,
>> +			 u8 offset, u8 size, u8 *buf)
>> +{
>> +	struct virtio_device *virtio_dev >> +	
virtio_pci_vf_get_pf_dev(virtvdev->core_device.pdev);
>> +	struct virtio_admin_cmd_data_lr_read *in;
>> +	struct scatterlist in_sg, out_sg;
>> +	struct virtio_admin_cmd cmd = {};
>> +	int ret;
>> +
>> +	if (!virtio_dev)
>> +		return -ENOTCONN;
>> +
>> +	in = kzalloc(sizeof(*in), GFP_KERNEL);
>> +	if (!in)
>> +		return -ENOMEM;
>> +
>> +	in->offset = offset;
>> +	sg_init_one(&in_sg, in, sizeof(*in));
>> +	sg_init_one(&out_sg, buf, size);
>> +	cmd.opcode = opcode;
>> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
>> +	cmd.data_sg = &in_sg;
>> +	cmd.result_sg = &out_sg;
>> +	cmd.group_member_id = virtvdev->vf_id + 1;
>> +	ret = virtio_admin_cmd_exec(virtio_dev, &cmd);
>> +
>> +	kfree(in);
>> +	return ret;
>> +}
>> +
>> +int virtiovf_cmd_lq_read_notify(struct virtiovf_pci_core_device
*virtvdev,
>> +				u8 req_bar_flags, u8 *bar, u64 *bar_offset)
>> +{
>> +	struct virtio_device *virtio_dev >> +	
virtio_pci_vf_get_pf_dev(virtvdev->core_device.pdev);
>> +	struct virtio_admin_cmd_notify_info_result *out;
>> +	struct scatterlist out_sg;
>> +	struct virtio_admin_cmd cmd = {};
>> +	int ret;
>> +
>> +	if (!virtio_dev)
>> +		return -ENOTCONN;
>> +
>> +	out = kzalloc(sizeof(*out), GFP_KERNEL);
>> +	if (!out)
>> +		return -ENOMEM;
>> +
>> +	sg_init_one(&out_sg, out, sizeof(*out));
>> +	cmd.opcode = VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO;
>> +	cmd.group_type = VIRTIO_ADMIN_GROUP_TYPE_SRIOV;
>> +	cmd.result_sg = &out_sg;
>> +	cmd.group_member_id = virtvdev->vf_id + 1;
>> +	ret = virtio_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 = &out->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(out);
>> +	return ret;
>> +}
>> diff --git a/drivers/vfio/pci/virtio/cmd.h
b/drivers/vfio/pci/virtio/cmd.h
>> new file mode 100644
>> index 000000000000..c2a3645f4b90
>> --- /dev/null
>> +++ b/drivers/vfio/pci/virtio/cmd.h
>> @@ -0,0 +1,27 @@
>> +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
>> +/*
>> + * Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights
reserved.
>> + */
>> +
>> +#ifndef VIRTIO_VFIO_CMD_H
>> +#define VIRTIO_VFIO_CMD_H
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/virtio.h>
>> +#include <linux/vfio_pci_core.h>
>> +#include <linux/virtio_pci.h>
>> +
>> +struct virtiovf_pci_core_device {
>> +	struct vfio_pci_core_device core_device;
>> +	int vf_id;
>> +};
>> +
>> +int virtiovf_cmd_list_query(struct pci_dev *pdev, u8 *buf, int
buf_size);
>> +int virtiovf_cmd_list_use(struct pci_dev *pdev, u8 *buf, int
buf_size);
>> +int virtiovf_cmd_lr_write(struct virtiovf_pci_core_device *virtvdev,
u16 opcode,
>> +			  u8 offset, u8 size, u8 *buf);
>> +int virtiovf_cmd_lr_read(struct virtiovf_pci_core_device *virtvdev,
u16 opcode,
>> +			 u8 offset, u8 size, u8 *buf);
>> +int virtiovf_cmd_lq_read_notify(struct virtiovf_pci_core_device
*virtvdev,
>> +				u8 req_bar_flags, u8 *bar, u64 *bar_offset);
>> +#endif /* VIRTIO_VFIO_CMD_H */
>> -- 
>> 2.27.0

Virtualization - Sep 2023 - [PATCH vfio 10/11] vfio/virtio: Expose admin commands over virtio device

[PATCH vfio 10/11] vfio/virtio: Expose admin commands over virtio device

[PATCH vfio 10/11] vfio/virtio: Expose admin commands over virtio device