blk_get_max_transfer() works only with sg

Bug #1893634 reported by Tom Yan
This bug affects 1 person
Affects Status Importance Assigned to Milestone

Bug Description

blk_get_max_transfer() is supposed to be able to get the max_sectors queue limit of the scsi device on the host side and is used in both scsi-generic.c (for scsi-generic and scsi-block) and scsi-disk.c (for scsi-hd) to set/change the max_xfer_len (and opt_xfer_len in the case of scsi-generic.c).

However, it only works with the sg driver in doing so. It cannot get the queue limit with the sd driver and simply returns MAX_INT.

qemu version 5.1.0
kernel version 5.8.5

Btw, is there a particular reason that it doesn't MIN_NON_ZERO against the original max_xfer_len:

Tom Yan (tom-ty89)
description: updated
Revision history for this message
Thomas Huth (th-huth) wrote :

The QEMU project is currently moving its bug tracking to another system.
For this we need to know which bugs are still valid and which could be
closed already. Thus we are setting the bug state to "Incomplete" now.

If the bug has already been fixed in the latest upstream version of QEMU,
then please close this ticket as "Fix released".

If it is not fixed yet and you think that this bug report here is still
valid, then you have two options:

1) If you already have an account on, please open a new ticket
for this problem in our new tracker here:

and then close this ticket here on Launchpad (or let it expire auto-
matically after 60 days). Please mention the URL of this bug ticket on
Launchpad in the new ticket on GitLab.

2) If you don't have an account on and don't intend to get
one, but still would like to keep this ticket opened, then please switch
the state back to "New" or "Confirmed" within the next 60 days (other-
wise it will get closed as "Expired"). We will then eventually migrate
the ticket automatically to the new system (but you won't be the reporter
of the bug in the new system and thus you won't get notified on changes

Thank you and sorry for the inconvenience.

Changed in qemu:
status: New → Incomplete
Revision history for this message
Launchpad Janitor (janitor) wrote :

[Expired for QEMU because there has been no activity for 60 days.]

Changed in qemu:
status: Incomplete → Expired
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