On 10/17/2017 02:36 PM, Thomas Huth wrote:
On 17.10.2017 18:27, Daniel Henrique Barboza wrote:
On 10/17/2017 11:32 AM, Thomas Huth wrote:
So far the CPU hot-plug qtest was only checking "cpu-add" on x86. With
these patches, we now test "device_add" for hot-plugging CPUs on x86,
and enable the test on ppc64 and s390x, too.
Question: is there a reason other than "no one bothered" to not have a
CPU hot
unplug test, something around the lines of the now cpu-plug-test.c? I might
give it a shot if there is no known roadblocks against it.
AFAIK on x86, you need some ACPI magic on the guest side to do this
(something similar to qpci_unplug_acpi_device_test() in
tests/libqos/pci-pc.c I guess). And on s390x, CPU unplug is not
supported at all. But it might work on ppc64 without guest intervention,
not sure - maybe Bharata can comment on this...
Good point, it won't work in spapr machine without guest intervention too.
Both CPU and LMB unplug relies on guest-side callbacks to complete the
operation.
I'll see how this ACPI magic you mentioned is done and see how hard it is to
do it for ppc64.
Daniel
Thomas
