From: Daniel Henrique Barboza <danielhb413@gmail.com>
To: qemu-devel@nongnu.org
Cc: Daniel Henrique Barboza <danielhb413@gmail.com>,
qemu-ppc@nongnu.org, groug@kaod.org, david@gibson.dropbear.id.au
Subject: [PATCH 0/1] pSeries: handle hotunplug errors in drc_unisolate_logical()
Date: Fri, 16 Apr 2021 18:09:40 -0300 [thread overview]
Message-ID: <20210416210941.381119-1-danielhb413@gmail.com> (raw)
Hi,
This is the QEMU side of a kernel change being proposed in [1],
where an attempt to implement a CPU hotunplug error report
mechanism was proposed.
The idea was discussed first in this mailing list [2], where the
RTAS set-indicator call would be used to signal QEMU when a kernel
side error happens during the unplug process.
Using the modified kernel and this patch, this is the result of a
failed CPU hotunplug attempt when trying to unplug the last online
CPU of the guest:
( QEMU command line: qemu-system-ppc64 -machine pseries,accel=kvm,usb=off
-smp 1,maxcpus=2,threads=1,cores=2,sockets=1 ... )
[root@localhost ~]# QEMU 5.2.92 monitor - type 'help' for more information
(qemu) device_add host-spapr-cpu-core,core-id=1,id=core1
(qemu)
[root@localhost ~]# echo 0 > /sys/devices/system/cpu/cpu0/online
[ 77.548442][ T13] IRQ 19: no longer affine to CPU0
[ 77.548452][ T13] IRQ 20: no longer affine to CPU0
[ 77.548458][ T13] IRQ 256: no longer affine to CPU0
[ 77.548465][ T13] IRQ 258: no longer affine to CPU0
[ 77.548472][ T13] IRQ 259: no longer affine to CPU0
[ 77.548479][ T13] IRQ 260: no longer affine to CPU0
[ 77.548485][ T13] IRQ 261: no longer affine to CPU0
[ 77.548590][ T0] cpu 0 (hwid 0) Ready to die...
[root@localhost ~]# (qemu)
(qemu) device_del core1
(qemu) [ 83.214073][ T100] pseries-hotplug-cpu: Failed to offline CPU PowerPC,POWER9, rc: -16
qemu-system-ppc64: Device hotunplug rejected by the guest for device core1
(qemu)
As mentioned in the kernel change, if this is accepted I'll push
for a PAPR change to make this an official device removal error
report mechanism.
[1] https://lore.kernel.org/linuxppc-dev/20210416210216.380291-3-danielhb413@gmail.com/
[2] https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg06395.html
Daniel Henrique Barboza (1):
spapr_drc.c: handle hotunplug errors in drc_unisolate_logical()
hw/ppc/spapr_drc.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
--
2.30.2
next reply other threads:[~2021-04-16 22:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-16 21:09 Daniel Henrique Barboza [this message]
2021-04-16 21:09 ` [PATCH 1/1] spapr_drc.c: handle hotunplug errors in drc_unisolate_logical() Daniel Henrique Barboza
2021-04-19 4:08 ` David Gibson
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