On 17. 3. 2020 1:01, Daniel Henrique Barboza wrote:
Commit 7b79ee2f78 makes assumptions about die_id parsing in the sysfs that aren't true for Power hosts. In both Power8 and Power9, running 5.6 and 4.18 kernel respectively, 'die_id' is set to -1:
$ cat /sys/devices/system/cpu/cpu0/topology/die_id -1
This breaks virHostCPUGetDie() parsing because it is trying to retrieve an unsigned integer, causing problems during VM start:
virFileReadValueUint:4128 : internal error: Invalid unsigned integer value '-1' in file '/sys/devices/system/cpu/cpu0/topology/die_id'
This isn't necessarily a PowerPC only behavior. Linux kernel commit 0e344d8c70 added in the former Documentation/cputopology.txt, now Documentation/admin-guide/cputopology.rst, that:
---
This line makes git-am cut the commit message here. I'm dropping it and increasing indend of the paragraph below.
To be consistent on all architectures, include/linux/topology.h provides default definitions for any of the above macros that are not defined by include/asm-XXX/topology.h:
1) topology_physical_package_id: -1 2) topology_die_id: -1 (...) ---
This means that it can be expected that an architecture that does not implement the die_id element will mark it as -1 in sysfs.
Let's change the parsing being done in virHostCPUGetDie(), reading die_id as an integer instead of unsigned int. In case die_id is -1, default it to zero like the case of file not found.
Fixes: 7b79ee2f78bbf2af76df2f6466919e19ae05aeeb Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> --- src/util/virhostcpu.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-)
Reviewed-by: Michal Privoznik <mprivozn@redhat.com> and pushed. Michal