[PATCH 12/17] xen: pvblock: Add initial support for para-virtualized block driver

Heinrich Schuchardt xypron.glpk at gmx.de
Thu Jul 2 06:29:29 CEST 2020


On 7/1/20 6:29 PM, Anastasiia Lukianenko wrote:
> From: Anastasiia Lukianenko <anastasiia_lukianenko at epam.com>
>
> Add initial infrastructure for Xen para-virtualized block device.
> This includes compile-time configuration and the skeleton for
> the future driver implementation.
> Add new class UCLASS_PVBLOCK which is going to be a parent for
> virtual block devices.

We already have virtual block devices: virtio_blk, efi_blk.

They work fine using the exising UCLASS_BLK. Why do we need a new uclass?

> Add new interface type IF_TYPE_PVBLOCK.
>
> Implement basic driver setup by reading XenStore configuration.
>
> Signed-off-by: Andrii Anisov <andrii_anisov at epam.com>
> Signed-off-by: Anastasiia Lukianenko <anastasiia_lukianenko at epam.com>
> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko at epam.com>
> ---
>  cmd/Kconfig                      |   7 ++
>  cmd/Makefile                     |   1 +
>  cmd/pvblock.c                    |  31 ++++++++
>  common/board_r.c                 |  14 ++++
>  configs/xenguest_arm64_defconfig |   4 +
>  disk/part.c                      |   4 +
>  drivers/Kconfig                  |   2 +
>  drivers/block/blk-uclass.c       |   2 +
>  drivers/xen/Kconfig              |  10 +++
>  drivers/xen/Makefile             |   2 +
>  drivers/xen/pvblock.c            | 121 +++++++++++++++++++++++++++++++
>  include/blk.h                    |   1 +
>  include/configs/xenguest_arm64.h |   8 ++
>  include/dm/uclass-id.h           |   1 +
>  include/pvblock.h                |  12 +++
>  15 files changed, 220 insertions(+)
>  create mode 100644 cmd/pvblock.c
>  create mode 100644 drivers/xen/Kconfig
>  create mode 100644 drivers/xen/pvblock.c
>  create mode 100644 include/pvblock.h
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 192b3b262f..f28576947b 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -1335,6 +1335,13 @@ config CMD_USB_MASS_STORAGE
>  	help
>  	  USB mass storage support
>
> +config CMD_PVBLOCK
> +	bool "Xen para-virtualized block device"
> +	depends on XEN
> +	select PVBLOCK
> +	help
> +	  Xen para-virtualized block device support
> +
>  config CMD_VIRTIO
>  	bool "virtio"
>  	depends on VIRTIO
> diff --git a/cmd/Makefile b/cmd/Makefile
> index 974ad48b0a..117284a28c 100644
> --- a/cmd/Makefile
> +++ b/cmd/Makefile
> @@ -169,6 +169,7 @@ obj-$(CONFIG_CMD_DFU) += dfu.o
>  obj-$(CONFIG_CMD_GPT) += gpt.o
>  obj-$(CONFIG_CMD_ETHSW) += ethsw.o
>  obj-$(CONFIG_CMD_AXI) += axi.o
> +obj-$(CONFIG_CMD_PVBLOCK) += pvblock.o
>
>  # Power
>  obj-$(CONFIG_CMD_PMIC) += pmic.o
> diff --git a/cmd/pvblock.c b/cmd/pvblock.c
> new file mode 100644
> index 0000000000..7dbb243a74
> --- /dev/null
> +++ b/cmd/pvblock.c
> @@ -0,0 +1,31 @@
> +/*
> + * SPDX-License-Identifier:	GPL-2.0+

Please, correct the formatting.

https://www.kernel.org/doc/html/latest/process/license-rules.html#license-identifier-syntax

> + *
> + * (C) Copyright 2020 EPAM Systems Inc.
> + *
> + * XEN para-virtualized block device support
> + */
> +
> +#include <blk.h>
> +#include <common.h>
> +#include <command.h>
> +
> +/* Current I/O Device	*/
> +static int pvblock_curr_device;
> +
> +int do_pvblock(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
> +{
> +	return blk_common_cmd(argc, argv, IF_TYPE_PVBLOCK,
> +			      &pvblock_curr_device);
> +}
> +
> +U_BOOT_CMD(pvblock, 5, 1, do_pvblock,
> +	   "Xen para-virtualized block device",
> +	   "info  - show available block devices\n"
> +	   "pvblock device [dev] - show or set current device\n"
> +	   "pvblock part [dev] - print partition table of one or all devices\n"
> +	   "pvblock read  addr blk# cnt\n"
> +	   "pvblock write addr blk# cnt - read/write `cnt'"
> +	   " blocks starting at block `blk#'\n"
> +	   "    to/from memory address `addr'");
> +
> diff --git a/common/board_r.c b/common/board_r.c
> index fd36edb4e5..40cd0e5d3c 100644
> --- a/common/board_r.c
> +++ b/common/board_r.c
> @@ -49,6 +49,7 @@
>  #include <nand.h>
>  #include <of_live.h>
>  #include <onenand_uboot.h>
> +#include <pvblock.h>
>  #include <scsi.h>
>  #include <serial.h>
>  #include <status_led.h>
> @@ -470,6 +471,16 @@ static int initr_xen(void)
>  	return 0;
>  }
>  #endif
> +
> +#ifdef CONFIG_PVBLOCK
> +static int initr_pvblock(void)
> +{
> +	puts("PVBLOCK: ");
> +	pvblock_init();
> +	return 0;
> +}
> +#endif
> +
>  /*
>   * Tell if it's OK to load the environment early in boot.
>   *
> @@ -780,6 +791,9 @@ static init_fnc_t init_sequence_r[] = {
>  #endif
>  #ifdef CONFIG_XEN
>  	initr_xen,
> +#endif
> +#ifdef CONFIG_PVBLOCK
> +	initr_pvblock,
>  #endif
>  	initr_env,
>  #ifdef CONFIG_SYS_BOOTPARAMS_LEN
> diff --git a/configs/xenguest_arm64_defconfig b/configs/xenguest_arm64_defconfig
> index 45559a161b..46473c251d 100644
> --- a/configs/xenguest_arm64_defconfig
> +++ b/configs/xenguest_arm64_defconfig
> @@ -14,6 +14,8 @@ CONFIG_CMD_BOOTD=n
>  CONFIG_CMD_BOOTEFI=n
>  CONFIG_CMD_BOOTEFI_HELLO_COMPILE=n
>  CONFIG_CMD_ELF=n
> +CONFIG_CMD_EXT4=y
> +CONFIG_CMD_FAT=y
>  CONFIG_CMD_GO=n
>  CONFIG_CMD_RUN=n
>  CONFIG_CMD_IMI=n
> @@ -41,6 +43,8 @@ CONFIG_CMD_LZMADEC=n
>  CONFIG_CMD_SAVEENV=n
>  CONFIG_CMD_UMS=n
>
> +CONFIG_CMD_PVBLOCK=y
> +
>  #CONFIG_USB=n
>  # CONFIG_ISO_PARTITION is not set
>
> diff --git a/disk/part.c b/disk/part.c
> index f6a31025dc..b69fd345f3 100644
> --- a/disk/part.c
> +++ b/disk/part.c
> @@ -149,6 +149,7 @@ void dev_print (struct blk_desc *dev_desc)
>  	case IF_TYPE_MMC:
>  	case IF_TYPE_USB:
>  	case IF_TYPE_NVME:
> +	case IF_TYPE_PVBLOCK:
>  		printf ("Vendor: %s Rev: %s Prod: %s\n",
>  			dev_desc->vendor,
>  			dev_desc->revision,
> @@ -288,6 +289,9 @@ static void print_part_header(const char *type, struct blk_desc *dev_desc)
>  	case IF_TYPE_NVME:
>  		puts ("NVMe");
>  		break;
> +	case IF_TYPE_PVBLOCK:
> +		puts("PV BLOCK");
> +		break;
>  	case IF_TYPE_VIRTIO:
>  		puts("VirtIO");
>  		break;
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index e34a22708c..65076aab03 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -132,6 +132,8 @@ source "drivers/w1-eeprom/Kconfig"
>
>  source "drivers/watchdog/Kconfig"
>
> +source "drivers/xen/Kconfig"
> +
>  config PHYS_TO_BUS
>  	bool "Custom physical to bus address mapping"
>  	help
> diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
> index b19375cbc8..6cfabbca24 100644
> --- a/drivers/block/blk-uclass.c
> +++ b/drivers/block/blk-uclass.c
> @@ -28,6 +28,7 @@ static const char *if_typename_str[IF_TYPE_COUNT] = {
>  	[IF_TYPE_NVME]		= "nvme",
>  	[IF_TYPE_EFI]		= "efi",
>  	[IF_TYPE_VIRTIO]	= "virtio",
> +	[IF_TYPE_PVBLOCK]	= "pvblock",
>  };
>
>  static enum uclass_id if_type_uclass_id[IF_TYPE_COUNT] = {
> @@ -43,6 +44,7 @@ static enum uclass_id if_type_uclass_id[IF_TYPE_COUNT] = {
>  	[IF_TYPE_NVME]		= UCLASS_NVME,
>  	[IF_TYPE_EFI]		= UCLASS_EFI,
>  	[IF_TYPE_VIRTIO]	= UCLASS_VIRTIO,
> +	[IF_TYPE_PVBLOCK]	= UCLASS_PVBLOCK,
>  };
>
>  static enum if_type if_typename_to_iftype(const char *if_typename)
> diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
> new file mode 100644
> index 0000000000..6ad2a93668
> --- /dev/null
> +++ b/drivers/xen/Kconfig
> @@ -0,0 +1,10 @@
> +config PVBLOCK
> +	bool "Xen para-virtualized block device"
> +	depends on DM
> +	select BLK
> +	select HAVE_BLOCK_DEVICE
> +	help
> +	  This driver implements the front-end of the Xen virtual
> +	  block device driver. It communicates with a back-end driver
> +	  in another domain which drives the actual block device.
> +
> diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile
> index 243b13277a..87157df69b 100644
> --- a/drivers/xen/Makefile
> +++ b/drivers/xen/Makefile
> @@ -6,3 +6,5 @@ obj-y += hypervisor.o
>  obj-y += events.o
>  obj-y += xenbus.o
>  obj-y += gnttab.o
> +
> +obj-$(CONFIG_PVBLOCK) += pvblock.o
> diff --git a/drivers/xen/pvblock.c b/drivers/xen/pvblock.c
> new file mode 100644
> index 0000000000..057add9753
> --- /dev/null
> +++ b/drivers/xen/pvblock.c
> @@ -0,0 +1,121 @@
> +/*
> + * SPDX-License-Identifier:	GPL-2.0+

See above.

> + *
> + * (C) Copyright 2020 EPAM Systems Inc.
> + */
> +#include <blk.h>
> +#include <common.h>
> +#include <dm.h>
> +#include <dm/device-internal.h>
> +
> +#define DRV_NAME	"pvblock"
> +#define DRV_NAME_BLK	"pvblock_blk"
> +
> +struct blkfront_dev {
> +	char dummy;
> +};
> +
> +static int init_blkfront(unsigned int devid, struct blkfront_dev *dev)
> +{
> +	return 0;
> +}
> +
> +static void shutdown_blkfront(struct blkfront_dev *dev)
> +{
> +}
> +
> +ulong pvblock_blk_read(struct udevice *udev, lbaint_t blknr, lbaint_t blkcnt,
> +		       void *buffer)
> +{
> +	return 0;
> +}
> +
> +ulong pvblock_blk_write(struct udevice *udev, lbaint_t blknr, lbaint_t blkcnt,
> +			const void *buffer)
> +{
> +	return 0;
> +}
> +
> +static int pvblock_blk_bind(struct udevice *udev)
> +{
> +	return 0;
> +}
> +
> +static int pvblock_blk_probe(struct udevice *udev)
> +{
> +	struct blkfront_dev *blk_dev = dev_get_priv(udev);
> +	int ret;
> +
> +	ret = init_blkfront(0, blk_dev);
> +	if (ret < 0)
> +		return ret;
> +	return 0;
> +}
> +
> +static int pvblock_blk_remove(struct udevice *udev)
> +{
> +	struct blkfront_dev *blk_dev = dev_get_priv(udev);
> +
> +	shutdown_blkfront(blk_dev);
> +	return 0;
> +}
> +
> +static const struct blk_ops pvblock_blk_ops = {
> +	.read	= pvblock_blk_read,
> +	.write	= pvblock_blk_write,
> +};
> +
> +U_BOOT_DRIVER(pvblock_blk) = {
> +	.name			= DRV_NAME_BLK,
> +	.id			= UCLASS_BLK,
> +	.ops			= &pvblock_blk_ops,
> +	.bind			= pvblock_blk_bind,
> +	.probe			= pvblock_blk_probe,
> +	.remove			= pvblock_blk_remove,
> +	.priv_auto_alloc_size	= sizeof(struct blkfront_dev),
> +	.flags			= DM_FLAG_OS_PREPARE,
> +};
> +
> +/*******************************************************************************
> + * Para-virtual block device class
> + *******************************************************************************/
> +
> +void pvblock_init(void)
> +{
> +	struct driver_info info;
> +	struct udevice *udev;
> +	struct uclass *uc;
> +	int ret;
> +
> +	/*
> +	 * At this point Xen drivers have already initialized,
> +	 * so we can instantiate the class driver and enumerate
> +	 * virtual block devices.
> +	 */
> +	info.name = DRV_NAME;
> +	ret = device_bind_by_name(gd->dm_root, false, &info, &udev);
> +	if (ret < 0)
> +		printf("Failed to bind " DRV_NAME ", ret: %d\n", ret);
> +
> +	/* Bootstrap virtual block devices class driver */
> +	ret = uclass_get(UCLASS_PVBLOCK, &uc);
> +	if (ret)
> +		return;
> +	uclass_foreach_dev_probe(UCLASS_PVBLOCK, udev);
> +}
> +
> +static int pvblock_probe(struct udevice *udev)
> +{
> +	return 0;
> +}
> +
> +U_BOOT_DRIVER(pvblock_drv) = {
> +	.name		= DRV_NAME,
> +	.id		= UCLASS_PVBLOCK,
> +	.probe		= pvblock_probe,
> +};
> +
> +UCLASS_DRIVER(pvblock) = {
> +	.name		= DRV_NAME,
> +	.id		= UCLASS_PVBLOCK,
> +};
> diff --git a/include/blk.h b/include/blk.h
> index abcd4bedbb..9ee10fb80e 100644
> --- a/include/blk.h
> +++ b/include/blk.h
> @@ -33,6 +33,7 @@ enum if_type {
>  	IF_TYPE_HOST,
>  	IF_TYPE_NVME,
>  	IF_TYPE_EFI,
> +	IF_TYPE_PVBLOCK,
>  	IF_TYPE_VIRTIO,
>
>  	IF_TYPE_COUNT,			/* Number of interface types */
> diff --git a/include/configs/xenguest_arm64.h b/include/configs/xenguest_arm64.h
> index 467dabf1e5..2c0d3d64fb 100644
> --- a/include/configs/xenguest_arm64.h
> +++ b/include/configs/xenguest_arm64.h
> @@ -42,4 +42,12 @@
>  #define CONFIG_CMDLINE_TAG            1
>  #define CONFIG_INITRD_TAG             1
>
> +#define CONFIG_CMD_RUN
> +
> +#undef CONFIG_EXTRA_ENV_SETTINGS
> +#define CONFIG_EXTRA_ENV_SETTINGS	\
> +	"loadimage=ext4load pvblock 0 0x90000000 /boot/Image;\0" \
> +	"pvblockboot=run loadimage;" \
> +		"booti 0x90000000 - 0x88000000;\0"
> +
>  #endif /* __XENGUEST_ARM64_H */
> diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
> index 7837d459f1..4bf7501204 100644
> --- a/include/dm/uclass-id.h
> +++ b/include/dm/uclass-id.h
> @@ -121,6 +121,7 @@ enum uclass_id {
>  	UCLASS_W1,		/* Dallas 1-Wire bus */
>  	UCLASS_W1_EEPROM,	/* one-wire EEPROMs */
>  	UCLASS_WDT,		/* Watchdog Timer driver */
> +	UCLASS_PVBLOCK,		/* Xen virtual block device */
>
>  	UCLASS_COUNT,
>  	UCLASS_INVALID = -1,
> diff --git a/include/pvblock.h b/include/pvblock.h
> new file mode 100644
> index 0000000000..e3bb8ff9a7
> --- /dev/null
> +++ b/include/pvblock.h
> @@ -0,0 +1,12 @@
> +/*
> + * SPDX-License-Identifier:	GPL-2.0+

See above.

scripts/checkpatch.pl is your friend.

> + *
> + * (C) 2020 EPAM Systems Inc.
> + */
> +
> +#ifndef _PVBLOCK_H
> +#define _PVBLOCK_H
> +

Document you functions as described in

https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html#function-documentation

Include the documentation in the HTML documentation generated by

    make htmldocs.

Best regards

Heinrich

> +void pvblock_init(void);
> +
> +#endif /* _PVBLOCK_H */
>



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