ppc64: fix compressed dump with pseries kernel

If we don't provide the page size in target-ppc:cpu_get_dump_info(),
the default one (TARGET_PAGE_SIZE, 4KB) is used to create
the compressed dump. It works fine with Macintosh, but not with
pseries as the kernel default page size is 64KB.

Without this patch, if we generate a compressed dump in the QEMU monitor:

    (qemu) dump-guest-memory -z qemu.dump

This dump cannot be read by crash:

    # crash vmlinux qemu.dump
    ...
    WARNING: cannot translate vmemmap kernel virtual addresses:
             commands requiring page structure contents will fail
    ...

Page_size is used to determine the dumpfile's block size. The
block size needs to be at least the page size, but a multiple of page
size works fine too. For PPC64, linux supports either 4KB or 64KB software
page size. So we define the page_size to 64KB.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Laurent Vivier 2016-08-08 15:08:53 +02:00 committed by David Gibson
parent 2bb15bddf2
commit 760d88d1d0

View file

@ -220,6 +220,11 @@ int cpu_get_dump_info(ArchDumpInfo *info,
} else {
info->d_endian = ELFDATA2LSB;
}
/* 64KB is the max page size for pseries kernel */
if (strncmp(object_get_typename(qdev_get_machine()),
"pseries-", 8) == 0) {
info->page_size = (1U << 16);
}
return 0;
}