powerpc/fadump: collect dump when CPU_STATE_DATA is less than reserved

During Fadump in Qemu VM, when maxcpus value is set to more than current
cpus, following failure is observed.

    [    0.045806] [      T1] rtas fadump: Dump taken by platform is
        incomplete (0)

This is because the CPU_STATE_DATA is allocated for maxcpus, while the
data is only filled for current cpus. As per current implementation
of Fadump, dumped_bytes and source_len for a region have to match,
Which is failing for qemu's case, Even tough the dumped bytes are
reported correctly for only the current cpus. After this /proc/vmcore
generatition also fails.

Allowing dumped_bytes to be lesser than or equal to allocated length, for
CPU_STATE_DATA Fadump region.

Reported-by: Anushree Mathur <anushree.mathur@linux.vnet.ibm.com>
Closes: https://lore.kernel.org/all/5e66daf4-3f55-4044-94a5-4f50bb040849@linux.ibm.com/T/#u
Tested-by: Anushree Mathur <anushree.mathur@linux.ibm.com>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Shivang Upadhyay <shivangu@linux.ibm.com>
[Maddy: Fixed ppc -> powerpc in title]
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260928101646.415278-1-shivangu@linux.ibm.com

0 files changed, 0 insertions, 0 deletions