Add two commands to set/get parameters generically. One important goal of ublk is to provide generic framework for making block device by userspace flexibly. As one generic block device, there are still lots of block parameters, such as max_sectors, write_cache/fua, discard related limits, zoned parameters, ...., so this patch starts to add generic mechanism for set/get device parameters. Both generic block parameters(all kinds of queue settings) and ublk feature parameters can be covered with this way, then it becomes quite easy to extend in future. Add two parameter types are used so far: basic(covers basic queue setting and misc settings which can't be grouped easily) and discard, basic type must be set, and discard type becomes optional now This way provides mechanism to simulate any kind of generic block device from userspace easily, from both block queue setting viewpoint or ublk feature viewpoint. The style of putting all parameters together is suggested by Christoph.
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| @@ -15,6 +15,8 @@ · 14 unmodified lines | |||
| 15 | #define UBLK_CMD_DEL_DEV 0x05 | 15 | #define UBLK_CMD_DEL_DEV 0x05 |
| 16 | #define UBLK_CMD_START_DEV 0x06 | 16 | #define UBLK_CMD_START_DEV 0x06 |
| 17 | #define UBLK_CMD_STOP_DEV 0x07 | 17 | #define UBLK_CMD_STOP_DEV 0x07 |
| 18 | #define UBLK_CMD_SET_PARAMS 0x08 | ||
| 19 | #define UBLK_CMD_GET_PARAMS 0x09 | ||
| 18 | 20 | ||
| 19 | /* | 21 | /* |
| 20 | * IO commands, issued by ublk server, and handled by ublk driver. | 22 | * IO commands, issued by ublk server, and handled by ublk driver. |
| @@ -158,4 +160,49 @@ struct ublksrv_io_cmd { · 137 unmodified lines | |||
| 158 | __u64 addr; | 160 | __u64 addr; |
| 159 | }; | 161 | }; |
| 160 | 162 | ||
| 163 | struct ublk_param_basic { | ||
| 164 | #define UBLK_ATTR_READ_ONLY (1 << 0) | ||
| 165 | #define UBLK_ATTR_ROTATIONAL (1 << 1) | ||
| 166 | #define UBLK_ATTR_VOLATILE_CACHE (1 << 2) | ||
| 167 | #define UBLK_ATTR_FUA (1 << 3) | ||
| 168 | __u32 attrs; | ||
| 169 | __u8 logical_bs_shift; | ||
| 170 | __u8 physical_bs_shift; | ||
| 171 | __u8 io_opt_shift; | ||
| 172 | __u8 io_min_shift; | ||
| 173 | |||
| 174 | __u32 max_sectors; | ||
| 175 | __u32 chunk_sectors; | ||
| 176 | |||
| 177 | __u64 dev_sectors; | ||
| 178 | __u64 virt_boundary_mask; | ||
| 179 | }; | ||
| 180 | |||
| 181 | struct ublk_param_discard { | ||
| 182 | __u32 discard_alignment; | ||
| 183 | |||
| 184 | __u32 discard_granularity; | ||
| 185 | __u32 max_discard_sectors; | ||
| 186 | |||
| 187 | __u32 max_write_zeroes_sectors; | ||
| 188 | __u16 max_discard_segments; | ||
| 189 | __u16 reserved0; | ||
| 190 | }; | ||
| 191 | |||
| 192 | struct ublk_params { | ||
| 193 | /* | ||
| 194 | * Total length of parameters, userspace has to set 'len' for both | ||
| 195 | * SET_PARAMS and GET_PARAMS command, and driver may update len | ||
| 196 | * if two sides use different version of 'ublk_params', same with | ||
| 197 | * 'types' fields. | ||
| 198 | */ | ||
| 199 | __u32 len; | ||
| 200 | #define UBLK_PARAM_TYPE_BASIC (1 << 0) | ||
| 201 | #define UBLK_PARAM_TYPE_DISCARD (1 << 1) | ||
| 202 | __u32 types; /* types of parameter included */ | ||
| 203 | |||
| 204 | struct ublk_param_basic basic; | ||
| 205 | struct ublk_param_discard discard; | ||
| 206 | }; | ||
| 207 | |||
| 161 | #endif | 208 | #endif |