qemu-patch-raspberry4/target
Cédric Le Goater 9a94ee5bb1 spapr/rtas: disable the decrementer interrupt when a CPU is unplugged
When a CPU is stopped with the 'stop-self' RTAS call, its state
'halted' is switched to 1 and, in this case, the MSR is not taken into
account anymore in the cpu_has_work() routine. Only the pending
hardware interrupts are checked with their LPCR:PECE* enablement bit.

If the DECR timer fires after 'stop-self' is called and before the CPU
'stop' state is reached, the nearly-dead CPU will have some work to do
and the guest will crash. This case happens very frequently with the
not yet upstream P9 XIVE exploitation mode. In XICS mode, the DECR is
occasionally fired but after 'stop' state, so no work is to be done
and the guest survives.

I suspect there is a race between the QEMU mainloop triggering the
timers and the TCG CPU thread but I could not quite identify the root
cause. To be safe, let's disable in the LPCR all the exceptions which
can cause an exit while the CPU is in power-saving mode and reenable
them when the CPU is started.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-12-15 09:49:24 +11:00
..
alpha x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
arm target/arm: Extend PAR format determination 2017-12-13 17:59:25 +00:00
cris x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
hppa Capstone disassembler 2017-10-27 08:04:51 +01:00
i386 Miscellaneous bugfixes 2017-11-16 14:42:54 +00:00
lm32 x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
m68k x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
microblaze Capstone disassembler 2017-10-27 08:04:51 +01:00
mips x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
moxie moxie: cleanup cpu type name composition 2017-10-27 16:03:54 +02:00
nios2 Capstone disassembler 2017-10-27 08:04:51 +01:00
openrisc x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
ppc spapr/rtas: disable the decrementer interrupt when a CPU is unplugged 2017-12-15 09:49:24 +11:00
s390x s390x/tcg: fix DIAG 308 with > 1 VCPU (MTTCG) 2017-11-20 09:31:46 +01:00
sh4 x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
sparc linux-user/sparc: Put address for data faults where linux-user expects it 2017-11-07 21:59:18 +02:00
tilegx tcg: Initialize cpu_env generically 2017-10-24 13:53:42 -07:00
tricore x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
unicore32 x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00
xtensa x86/cpu/numa queue, 2017-10-27 2017-10-30 10:11:22 +00:00