tree cc4f673021aeaac13a60ec07b7f411168d7e36ec
parent 6190c0ccaf5dfee845df9c9cd8ad9fdc5856bb41
author Roger Pau Monne <roger.pau@citrix.com> 1610452438 +0100
committer Juergen Gross <jgross@suse.com> 1610537477 +0100

xen/privcmd: allow fetching resource sizes

Allow issuing an IOCTL_PRIVCMD_MMAP_RESOURCE ioctl with num = 0 and
addr = 0 in order to fetch the size of a specific resource.

Add a shortcut to the default map resource path, since fetching the
size requires no address to be passed in, and thus no VMA to setup.

This is missing from the initial implementation, and causes issues
when mapping resources that don't have fixed or known sizes.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: stable@vger.kernel.org # >= 4.18
Link: https://lore.kernel.org/r/20210112115358.23346-1-roger.pau@citrix.com
Signed-off-by: Juergen Gross <jgross@suse.com>