John Snow <js...@redhat.com> writes:
> Currently, if the block device backing the IDE drive is resized,
> the information about the device as cached inside of the IDEState
> structure is not updated, thus when a guest OS re-queries the drive,
> it is unable to see the expanded size.
>
> This patch adds a resize callback that updates the IDENTIFY data
> buffer in order to correct this.
>
> Lastly, a Linux guest as-is cannot resize a libata drive while in-use,
> but it can see the expanded size as part of a bus rescan event.
> This patch also allows guests such as Linux to see the new drive size
> after a soft reboot event, without having to exit the QEMU process.
>
> Signed-off-by: John Snow <js...@redhat.com>
> ---
>
> V3:
> - Factored out the size update into new functions.
> - Fixed the size update for CFATA.
> - Added assertion to clarify that ide_resize_cb is non-atapi.
>
> V2:
> - Do not attempt to update geometry values, to avoid clobbering
> user-specified values, if they exist.
> - Do not regenerate the entire IDENTIFY buffer to avoid losing
> any settings that occurred during normal operation.
>
> hw/ide/core.c | 69
> ++++++++++++++++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 59 insertions(+), 10 deletions(-)
>
> diff --git a/hw/ide/core.c b/hw/ide/core.c
> index db191a6..1fde54e 100644
> --- a/hw/ide/core.c
> +++ b/hw/ide/core.c
> @@ -75,6 +75,17 @@ static void put_le16(uint16_t *p, unsigned int v)
> *p = cpu_to_le16(v);
> }
>
> +static void ide_identify_size(IDEState *s)
> +{
> + uint16_t *p = (uint16_t *)s->identify_data;
> + put_le16(p + 60, s->nb_sectors);
> + put_le16(p + 61, s->nb_sectors >> 16);
> + put_le16(p + 100, s->nb_sectors);
> + put_le16(p + 101, s->nb_sectors >> 16);
> + put_le16(p + 102, s->nb_sectors >> 32);
> + put_le16(p + 103, s->nb_sectors >> 48);
> +}
This gave me pause, because identify_data() updates s->io_buffer, not
s->identify_data. It works fine, because...
> +
> static void ide_identify(IDEState *s)
> {
> uint16_t *p;
> @@ -116,8 +127,8 @@ static void ide_identify(IDEState *s)
> put_le16(p + 58, oldsize >> 16);
> if (s->mult_sectors)
> put_le16(p + 59, 0x100 | s->mult_sectors);
> - put_le16(p + 60, s->nb_sectors);
> - put_le16(p + 61, s->nb_sectors >> 16);
> + /* *(p + 60) := nb_sectors -- see ide_identify_size */
> + /* *(p + 61) := nb_sectors >> 16 -- see ide_identify_size */
> put_le16(p + 62, 0x07); /* single word dma0-2 supported */
> put_le16(p + 63, 0x07); /* mdma0-2 supported */
> put_le16(p + 64, 0x03); /* pio3-4 supported */
> @@ -162,10 +173,10 @@ static void ide_identify(IDEState *s)
> }
> put_le16(p + 88, 0x3f | (1 << 13)); /* udma5 set and supported */
> put_le16(p + 93, 1 | (1 << 14) | 0x2000);
> - put_le16(p + 100, s->nb_sectors);
> - put_le16(p + 101, s->nb_sectors >> 16);
> - put_le16(p + 102, s->nb_sectors >> 32);
> - put_le16(p + 103, s->nb_sectors >> 48);
> + /* *(p + 100) := nb_sectors -- see ide_identify_size */
> + /* *(p + 101) := nb_sectors >> 16 -- see ide_identify_size */
> + /* *(p + 102) := nb_sectors >> 32 -- see ide_identify_size */
> + /* *(p + 103) := nb_sectors >> 48 -- see ide_identify_size */
>
> if (dev && dev->conf.physical_block_size)
> put_le16(p + 106, 0x6000 | get_physical_block_exp(&dev->conf));
> @@ -181,6 +192,7 @@ static void ide_identify(IDEState *s)
> }
>
> memcpy(s->identify_data, p, sizeof(s->identify_data));
> + ide_identify_size(s);
> s->identify_set = 1;
> }
>
... you make it call ide_identify_size() after copying s->io_buffer to
s->identify_data.
> @@ -237,6 +249,15 @@ static void ide_atapi_identify(IDEState *s)
> s->identify_set = 1;
> }
>
> +static void ide_cfata_identify_size(IDEState *s)
> +{
> + uint16_t *p = (uint16_t *)s->identify_data;
> + put_le16(p + 7, s->nb_sectors >> 16); /* Sectors per card */
> + put_le16(p + 8, s->nb_sectors); /* Sectors per card */
> + put_le16(p + 60, s->nb_sectors); /* Total LBA sectors */
> + put_le16(p + 61, s->nb_sectors >> 16); /* Total LBA sectors */
> +}
> +
This one is easier to understand, because ide_cfata_identify()
constructs identify data where it belongs, in s->identify_data.
> static void ide_cfata_identify(IDEState *s)
> {
> uint16_t *p;
> @@ -254,8 +275,8 @@ static void ide_cfata_identify(IDEState *s)
> put_le16(p + 1, s->cylinders); /* Default cylinders */
> put_le16(p + 3, s->heads); /* Default heads */
> put_le16(p + 6, s->sectors); /* Default sectors per track */
> - put_le16(p + 7, s->nb_sectors >> 16); /* Sectors per card */
> - put_le16(p + 8, s->nb_sectors); /* Sectors per card */
> + /* *(p + 7) := nb_sectors >> 16 -- see ide_cfata_identify_size */
> + /* *(p + 8) := nb_sectors -- see ide_cfata_identify_size */
> padstr((char *)(p + 10), s->drive_serial_str, 20); /* serial number */
> put_le16(p + 22, 0x0004); /* ECC bytes */
> padstr((char *) (p + 23), s->version, 8); /* Firmware Revision */
> @@ -276,8 +297,8 @@ static void ide_cfata_identify(IDEState *s)
> put_le16(p + 58, cur_sec >> 16); /* Current capacity */
> if (s->mult_sectors) /* Multiple sector setting */
> put_le16(p + 59, 0x100 | s->mult_sectors);
> - put_le16(p + 60, s->nb_sectors); /* Total LBA sectors */
> - put_le16(p + 61, s->nb_sectors >> 16); /* Total LBA sectors */
> + /* *(p + 60) := nb_sectors -- see ide_cfata_identify_size */
> + /* *(p + 61) := nb_sectors >> 16 -- see ide_cfata_identify_size */
> put_le16(p + 63, 0x0203); /* Multiword DMA
> capability */
> put_le16(p + 64, 0x0001); /* Flow Control PIO
> support */
> put_le16(p + 65, 0x0096); /* Min. Multiword DMA
> cycle */
> @@ -297,6 +318,7 @@ static void ide_cfata_identify(IDEState *s)
> put_le16(p + 160, 0x8100); /* Power requirement */
> put_le16(p + 161, 0x8001); /* CF command set */
>
> + ide_cfata_identify_size(s);
> s->identify_set = 1;
>
> fill_buffer:
Factoring out the nb_sectors part removed the code duplication, but the
comments duplicate it right back %-)
I hope you didn't factor out just to please me. The choice is yours. I
hope I was able to convey that in my review of v2.
> @@ -2099,6 +2121,28 @@ static bool ide_cd_is_medium_locked(void *opaque)
> return ((IDEState *)opaque)->tray_locked;
> }
>
> +static void ide_resize_cb(void *opaque)
> +{
> + IDEState *s = opaque;
> + uint64_t nb_sectors;
> +
> + if (!s->identify_set) {
> + return;
> + }
> +
> + bdrv_get_geometry(s->bs, &nb_sectors);
> + s->nb_sectors = nb_sectors;
> +
> + /* Update the identify data buffer. */
> + if (s->drive_kind == IDE_CFATA) {
> + ide_cfata_identify_size(s);
> + } else {
> + /* IDE_CD uses a different set of callbacks entirely. */
> + assert(s->drive_kind != IDE_CD);
> + ide_identify_size(s);
> + }
If this happens while s->identify_set is still false, it's write-only.
Safe.
> +}
> +
> static const BlockDevOps ide_cd_block_ops = {
> .change_media_cb = ide_cd_change_cb,
> .eject_request_cb = ide_cd_eject_request_cb,
> @@ -2106,6 +2150,10 @@ static const BlockDevOps ide_cd_block_ops = {
> .is_medium_locked = ide_cd_is_medium_locked,
> };
>
> +static const BlockDevOps ide_hd_block_ops = {
> + .resize_cb = ide_resize_cb,
> +};
> +
> int ide_init_drive(IDEState *s, BlockDriverState *bs, IDEDriveKind kind,
> const char *version, const char *serial, const char
> *model,
> uint64_t wwn,
> @@ -2142,6 +2190,7 @@ int ide_init_drive(IDEState *s, BlockDriverState *bs,
> IDEDriveKind kind,
> error_report("Can't use a read-only drive");
> return -1;
> }
> + bdrv_set_dev_ops(bs, &ide_hd_block_ops, s);
> }
> if (serial) {
> pstrcpy(s->drive_serial_str, sizeof(s->drive_serial_str), serial);
Reviewed-by: Markus Armbruster <arm...@redhat.com>
