virtio-blk: add support for zoned block devices

This patch adds support for Zoned Block Devices (ZBDs) to the kernel
virtio-blk driver.

The patch accompanies the virtio-blk ZBD support draft that is now
being proposed for standardization. The latest version of the draft is
linked at

https://github.com/oasis-tcs/virtio-spec/issues/143 .

The QEMU zoned device code that implements these protocol extensions
has been developed by Sam Li and it is currently in review at the QEMU
mailing list.

A number of virtblk request structure changes has been introduced to
accommodate the functionality that is specific to zoned block devices
and, most importantly, make room for carrying the Zoned Append sector
value from the device back to the driver along with the request status.

The zone-specific code in the patch is heavily influenced by NVMe ZNS
code in drivers/nvme/host/zns.c, but it is simpler because the proposed
virtio ZBD draft only covers the zoned device features that are
relevant to the zoned functionality provided by Linux block layer.

includes the following fixup:

virtio-blk: fix probe without CONFIG_BLK_DEV_ZONED

When building without CONFIG_BLK_DEV_ZONED, VIRTIO_BLK_F_ZONED
is excluded from array of driver features.
As a result virtio_has_feature panics in virtio_check_driver_offered_feature
since that by design verifies that a feature we are checking for
is listed in the feature array.

To fix, replace the call to virtio_has_feature with a stub.

Message-Id: <20221016034127.330942-3-dmitry.fomichev@wdc.com>
Co-developed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
Message-Id: <20221220112340.518841-1-mst@redhat.com>
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reported-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Debugged-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

include/uapi/linux/virtio_blk.h

@@ -41,6 +41,7 @@
 #define VIRTIO_BLK_F_DISCARD	13	/* DISCARD is supported */
 #define VIRTIO_BLK_F_WRITE_ZEROES	14	/* WRITE ZEROES is supported */
 #define VIRTIO_BLK_F_SECURE_ERASE	16 /* Secure Erase is supported */
+#define VIRTIO_BLK_F_ZONED		17	/* Zoned block device */
 
 /* Legacy feature bits */
 #ifndef VIRTIO_BLK_NO_LEGACY
@@ -137,6 +138,16 @@ struct virtio_blk_config {
 	/* Secure erase commands must be aligned to this number of sectors. */
 	__virtio32 secure_erase_sector_alignment;
 
+	/* Zoned block device characteristics (if VIRTIO_BLK_F_ZONED) */
+	struct virtio_blk_zoned_characteristics {
+		__virtio32 zone_sectors;
+		__virtio32 max_open_zones;
+		__virtio32 max_active_zones;
+		__virtio32 max_append_sectors;
+		__virtio32 write_granularity;
+		__u8 model;
+		__u8 unused2[3];
+	} zoned;
 } __attribute__((packed));
 
 /*
@@ -174,6 +185,27 @@ struct virtio_blk_config {
 /* Secure erase command */
 #define VIRTIO_BLK_T_SECURE_ERASE	14
 
+/* Zone append command */
+#define VIRTIO_BLK_T_ZONE_APPEND    15
+
+/* Report zones command */
+#define VIRTIO_BLK_T_ZONE_REPORT    16
+
+/* Open zone command */
+#define VIRTIO_BLK_T_ZONE_OPEN      18
+
+/* Close zone command */
+#define VIRTIO_BLK_T_ZONE_CLOSE     20
+
+/* Finish zone command */
+#define VIRTIO_BLK_T_ZONE_FINISH    22
+
+/* Reset zone command */
+#define VIRTIO_BLK_T_ZONE_RESET     24
+
+/* Reset All zones command */
+#define VIRTIO_BLK_T_ZONE_RESET_ALL 26
+
 #ifndef VIRTIO_BLK_NO_LEGACY
 /* Barrier before this op. */
 #define VIRTIO_BLK_T_BARRIER	0x80000000
@@ -193,6 +225,72 @@ struct virtio_blk_outhdr {
 	__virtio64 sector;
 };
 
+/*
+ * Supported zoned device models.
+ */
+
+/* Regular block device */
+#define VIRTIO_BLK_Z_NONE      0
+/* Host-managed zoned device */
+#define VIRTIO_BLK_Z_HM        1
+/* Host-aware zoned device */
+#define VIRTIO_BLK_Z_HA        2
+
+/*
+ * Zone descriptor. A part of VIRTIO_BLK_T_ZONE_REPORT command reply.
+ */
+struct virtio_blk_zone_descriptor {
+	/* Zone capacity */
+	__virtio64 z_cap;
+	/* The starting sector of the zone */
+	__virtio64 z_start;
+	/* Zone write pointer position in sectors */
+	__virtio64 z_wp;
+	/* Zone type */
+	__u8 z_type;
+	/* Zone state */
+	__u8 z_state;
+	__u8 reserved[38];
+};
+
+struct virtio_blk_zone_report {
+	__virtio64 nr_zones;
+	__u8 reserved[56];
+	struct virtio_blk_zone_descriptor zones[];
+};
+
+/*
+ * Supported zone types.
+ */
+
+/* Conventional zone */
+#define VIRTIO_BLK_ZT_CONV         1
+/* Sequential Write Required zone */
+#define VIRTIO_BLK_ZT_SWR          2
+/* Sequential Write Preferred zone */
+#define VIRTIO_BLK_ZT_SWP          3
+
+/*
+ * Zone states that are available for zones of all types.
+ */
+
+/* Not a write pointer (conventional zones only) */
+#define VIRTIO_BLK_ZS_NOT_WP       0
+/* Empty */
+#define VIRTIO_BLK_ZS_EMPTY        1
+/* Implicitly Open */
+#define VIRTIO_BLK_ZS_IOPEN        2
+/* Explicitly Open */
+#define VIRTIO_BLK_ZS_EOPEN        3
+/* Closed */
+#define VIRTIO_BLK_ZS_CLOSED       4
+/* Read-Only */
+#define VIRTIO_BLK_ZS_RDONLY       13
+/* Full */
+#define VIRTIO_BLK_ZS_FULL         14
+/* Offline */
+#define VIRTIO_BLK_ZS_OFFLINE      15
+
 /* Unmap this range (only valid for write zeroes command) */
 #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP	0x00000001
 
@@ -219,4 +317,11 @@ struct virtio_scsi_inhdr {
 #define VIRTIO_BLK_S_OK		0
 #define VIRTIO_BLK_S_IOERR	1
 #define VIRTIO_BLK_S_UNSUPP	2
+
+/* Error codes that are specific to zoned block devices */
+#define VIRTIO_BLK_S_ZONE_INVALID_CMD     3
+#define VIRTIO_BLK_S_ZONE_UNALIGNED_WP    4
+#define VIRTIO_BLK_S_ZONE_OPEN_RESOURCE   5
+#define VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE 6
+
 #endif /* _LINUX_VIRTIO_BLK_H */