virtio_blk_defs.h

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#pragma once
 
#include <cstddef>
#include <cstdint>
 
namespace virtio::blk {
 
enum class BlkFeatureBit : uint64_t {
  kSizeMax = 1ULL << 1,
  kSegMax = 1ULL << 2,
  kGeometry = 1ULL << 4,
  kRo = 1ULL << 5,
  kBlkSize = 1ULL << 6,
  kFlush = 1ULL << 9,
  kTopology = 1ULL << 10,
  kConfigWce = 1ULL << 11,
  kMq = 1ULL << 12,
  kDiscard = 1ULL << 13,
  kWriteZeroes = 1ULL << 14,
  kLifetime = 1ULL << 15,
  kSecureErase = 1ULL << 16,
};
 
struct [[gnu::packed]] BlkConfig {
  uint64_t capacity;
  uint32_t size_max;
  uint32_t seg_max;
 
  struct [[gnu::packed]] {
    uint16_t cylinders;
    uint8_t heads;
    uint8_t sectors;
  } geometry;
 
  uint32_t blk_size;
 
  struct [[gnu::packed]] {
    uint8_t physical_block_exp;
    uint8_t alignment_offset;
    uint16_t min_io_size;
    uint32_t opt_io_size;
  } topology;
 
  uint8_t writeback;
  uint8_t unused0[3];
 
  uint32_t max_discard_sectors;
  uint32_t max_discard_seg;
  uint32_t discard_sector_alignment;
 
  uint32_t max_write_zeroes_sectors;
  uint32_t max_write_zeroes_seg;
  uint8_t write_zeroes_may_unmap;
  uint8_t unused1[3];
 
  uint32_t max_secure_erase_sectors;
  uint32_t max_secure_erase_seg;
  uint32_t secure_erase_sector_alignment;
 
  uint16_t num_queues;
  uint8_t unused2[6];
};
 
enum class BlkConfigOffset : uint32_t {
  kCapacity = 0,
  kSizeMax = 8,
  kSegMax = 12,
  kGeometryCylinders = 16,
  kGeometryHeads = 18,
  kGeometrySectors = 19,
  kBlkSize = 20,
  kTopologyPhysBlockExp = 24,
  kTopologyAlignOffset = 25,
  kTopologyMinIoSize = 26,
  kTopologyOptIoSize = 28,
  kWriteback = 32,
  kMaxDiscardSectors = 36,
  kMaxDiscardSeg = 40,
  kDiscardSectorAlignment = 44,
  kMaxWriteZeroesSectors = 48,
  kMaxWriteZeroesSeg = 52,
  kWriteZeroesMayUnmap = 56,
  kMaxSecureEraseSectors = 60,
  kMaxSecureEraseSeg = 64,
  kSecureEraseSectorAlignment = 68,
  kNumQueues = 72,
};
 
enum class ReqType : uint32_t {
  kIn = 0,
  kOut = 1,
  kFlush = 4,
  kGetId = 8,
  kGetLifetime = 10,
  kDiscard = 11,
  kWriteZeroes = 13,
  kSecureErase = 14,
};
 
enum class BlkStatus : uint8_t {
  kOk = 0,
  kIoErr = 1,
  kUnsupp = 2,
};
 
struct [[gnu::packed]] BlkReqHeader {
  uint32_t type;
  uint32_t reserved;
  uint64_t sector;
};
 
struct [[gnu::packed]] BlkDiscardWriteZeroes {
  uint64_t sector;
  uint32_t num_sectors;
  struct [[gnu::packed]] {
    uint32_t unmap : 1;
    uint32_t reserved : 31;
  } flags;
};
 
struct [[gnu::packed]] BlkLifetime {
  enum class PreEolInfo : uint16_t {
    kUndefined = 0,
    kNormal = 1,
    kWarning = 2,
    kUrgent = 3,
  };
 
  uint16_t pre_eol_info;
  uint16_t device_lifetime_est_typ_a;
  uint16_t device_lifetime_est_typ_b;
};
 
inline constexpr size_t kSectorSize = 512;
 
inline constexpr size_t kDeviceIdMaxLen = 20;
 
struct VirtioStats {
  uint64_t bytes_transferred{0};
  uint64_t kicks_elided{0};
  uint64_t interrupts_handled{0};
  uint64_t queue_full_errors{0};
};
 
}  // namespace virtio::blk