This patch implements the missing qemu logic to interpret a '-drive .. serial=XYZ ..' flag for a virtio_blk device.
The serial number string is contained in a skeletal IDENTIFY DEVICE data structure and this structure is made available to the guest virtio_blk driver via pci i/o region 0. Signed-off-by: john cooper <john.coo...@redhat.com> --- diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index 8dd3c7a..0b7ebe9 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -25,6 +25,7 @@ typedef struct VirtIOBlock BlockDriverState *bs; VirtQueue *vq; void *rq; + char serial_str[BLOCK_SERIAL_STRLEN + 1]; } VirtIOBlock; static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev) @@ -285,6 +286,50 @@ static void virtio_blk_reset(VirtIODevice *vdev) qemu_aio_flush(); } +/* store identify data in little endian format + */ +static inline void put_le16(uint16_t *p, unsigned int v) +{ + *p = cpu_to_le16(v); +} + +/* copy to *dst from *src, nul pad dst tail as needed to len bytes + */ +static inline void padstr(char *dst, const char *src, int len) +{ + while (len--) + *dst++ = *src ? *src++ : '\0'; +} + +/* setup simulated identify data as appropriate for virtio block device + * + * ref: AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS) + */ +static inline void virtio_identify_template(struct virtio_blk_config *bc) +{ + uint16_t *p = &bc->identify[0]; + uint64_t lba_sectors = bc->capacity; + + memset(p, 0, sizeof(bc->identify)); + put_le16(p + 0, 0x0); /* ATA device */ + padstr((char *)(p + 23), QEMU_VERSION, 8); /* firmware revision */ + padstr((char *)(p + 27), "QEMU VIRT_BLK", 40); /* model# */ + put_le16(p + 47, 0x80ff); /* max xfer 255 sectors */ + put_le16(p + 49, 0x0b00); /* support IORDY/LBA/DMA */ + put_le16(p + 59, 0x1ff); /* cur xfer 255 sectors */ + put_le16(p + 80, 0x1f0); /* support ATA8/7/6/5/4 */ + put_le16(p + 81, 0x16); + put_le16(p + 82, 0x400); + put_le16(p + 83, 0x400); + put_le16(p + 100, lba_sectors); + put_le16(p + 101, lba_sectors >> 16); + put_le16(p + 102, lba_sectors >> 32); + put_le16(p + 103, lba_sectors >> 48); +} + +/* coalesce internal state, copy to pci i/o region 0 + */ + static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) { VirtIOBlock *s = to_virtio_blk(vdev); @@ -299,11 +344,15 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config) stw_raw(&blkcfg.cylinders, cylinders); blkcfg.heads = heads; blkcfg.sectors = secs; + virtio_identify_template(&blkcfg); + memcpy(&blkcfg.identify[VIRTIO_BLK_ID_SN], s->serial_str, + VIRTIO_BLK_ID_SN_BYTES); memcpy(config, &blkcfg, sizeof(blkcfg)); } static uint32_t virtio_blk_get_features(VirtIODevice *vdev) { + VirtIOBlock *s = to_virtio_blk(vdev); uint32_t features = 0; features |= (1 << VIRTIO_BLK_F_SEG_MAX); @@ -311,6 +360,8 @@ static uint32_t virtio_blk_get_features(VirtIODevice *vdev) #ifdef __linux__ features |= (1 << VIRTIO_BLK_F_SCSI); #endif + if (strcmp(s->serial_str, "0")) + features |= 1 << VIRTIO_BLK_F_IDENTIFY; return features; } @@ -354,6 +405,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev) int cylinders, heads, secs; static int virtio_blk_id; BlockDriverState *bs; + char *ps; s = (VirtIOBlock *)virtio_common_init("virtio-blk", VIRTIO_ID_BLOCK, sizeof(struct virtio_blk_config), @@ -365,6 +417,10 @@ VirtIODevice *virtio_blk_init(DeviceState *dev) s->vdev.reset = virtio_blk_reset; s->bs = bs; s->rq = NULL; + if (strlen(ps = (char *)drive_get_serial(bs))) + strncpy(s->serial_str, ps, sizeof(s->serial_str)); + else + snprintf(s->serial_str, sizeof(s->serial_str), "0"); bs->private = dev; bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs); bdrv_set_geometry_hint(s->bs, cylinders, heads, secs); diff --git a/hw/virtio-blk.h b/hw/virtio-blk.h index dff3e0c..1be4342 100644 --- a/hw/virtio-blk.h +++ b/hw/virtio-blk.h @@ -30,6 +30,11 @@ #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ +#define VIRTIO_BLK_F_IDENTIFY 8 /* ATA IDENTIFY supported */ + +#define VIRTIO_BLK_ID_LEN 256 /* length of identify u16 array */ +#define VIRTIO_BLK_ID_SN 10 /* start of char * serial# */ +#define VIRTIO_BLK_ID_SN_BYTES 20 /* length in bytes of serial# */ struct virtio_blk_config { @@ -39,6 +44,8 @@ struct virtio_blk_config uint16_t cylinders; uint8_t heads; uint8_t sectors; + uint32_t _blk_size; /* structure pad, currently unused */ + uint16_t identify[VIRTIO_BLK_ID_LEN]; } __attribute__((packed)); /* These two define direction. */ diff --git a/sysemu.h b/sysemu.h index 47d001e..d3df19f 100644 --- a/sysemu.h +++ b/sysemu.h @@ -152,6 +152,8 @@ typedef enum { BLOCK_ERR_STOP_ANY } BlockInterfaceErrorAction; +#define BLOCK_SERIAL_STRLEN 20 + typedef struct DriveInfo { BlockDriverState *bdrv; BlockInterfaceType type; @@ -160,7 +162,7 @@ typedef struct DriveInfo { int used; int drive_opt_idx; BlockInterfaceErrorAction onerror; - char serial[21]; + char serial[BLOCK_SERIAL_STRLEN + 1]; } DriveInfo; #define MAX_IDE_DEVS 2 -- john.coo...@redhat.com -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html