linux/arch/powerpc/kvm
Jordan Niethe 7fe4e1176d powerpc/kvm: Fix kvmppc_vcore->in_guest value in kvmhv_switch_to_host
kvmhv_switch_to_host() in arch/powerpc/kvm/book3s_hv_rmhandlers.S
needs to set kvmppc_vcore->in_guest to 0 to signal secondary CPUs to
continue. This happens after resetting the PCR. Before commit
13c7bb3c57 ("powerpc/64s: Set reserved PCR bits"), r0 would always
be 0 before it was stored to kvmppc_vcore->in_guest. However because
of this change in the commit:

          /* Reset PCR */
          ld      r0, VCORE_PCR(r5)
  -       cmpdi   r0, 0
  +       LOAD_REG_IMMEDIATE(r6, PCR_MASK)
  +       cmpld   r0, r6
          beq     18f
  -       li      r0, 0
  -       mtspr   SPRN_PCR, r0
  +       mtspr   SPRN_PCR, r6
   18:
          /* Signal secondary CPUs to continue */
          stb     r0,VCORE_IN_GUEST(r5)

We are no longer comparing r0 against 0 and loading it with 0 if it
contains something else. Hence when we store r0 to
kvmppc_vcore->in_guest, it might not be 0. This means that secondary
CPUs will not be signalled to continue. Those CPUs get stuck and
errors like the following are logged:

    KVM: CPU 1 seems to be stuck
    KVM: CPU 2 seems to be stuck
    KVM: CPU 3 seems to be stuck
    KVM: CPU 4 seems to be stuck
    KVM: CPU 5 seems to be stuck
    KVM: CPU 6 seems to be stuck
    KVM: CPU 7 seems to be stuck

This can be reproduced with:
    $ for i in `seq 1 7` ; do chcpu -d $i ; done ;
    $ taskset -c 0 qemu-system-ppc64 -smp 8,threads=8 \
       -M pseries,accel=kvm,kvm-type=HV -m 1G -nographic -vga none \
       -kernel vmlinux -initrd initrd.cpio.xz

Fix by making sure r0 is 0 before storing it to
kvmppc_vcore->in_guest.

Fixes: 13c7bb3c57 ("powerpc/64s: Set reserved PCR bits")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191004025317.19340-1-jniethe5@gmail.com
2019-10-09 17:16:59 +11:00
..
book3s_32_mmu_host.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_32_mmu.c KVM: PPC: Book3S: Mark expected switch fall-through 2019-08-23 15:57:24 +10:00
book3s_32_sr.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_64_mmu_host.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_64_mmu_hv.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_64_mmu_radix.c powerpc updates for 5.3 2019-07-13 16:08:36 -07:00
book3s_64_mmu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_64_slb.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_64_vio_hv.c KVM: PPC: Book3S: Invalidate multiple TCEs at once 2019-08-30 09:40:14 +10:00
book3s_64_vio.c KVM: PPC: Book3S: Invalidate multiple TCEs at once 2019-08-30 09:40:14 +10:00
book3s_emulate.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_exports.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_hv_builtin.c powerpc updates for 5.3 2019-07-13 16:08:36 -07:00
book3s_hv_hmi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 114 2019-05-24 17:39:01 +02:00
book3s_hv_interrupts.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_hv_nested.c powerpc/64s: Set reserved PCR bits 2019-09-21 08:36:53 +10:00
book3s_hv_ras.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_hv_rm_mmu.c powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9 2019-09-24 20:58:55 +10:00
book3s_hv_rm_xics.c KVM: PPC: Book3S HV: use smp_mb() when setting/clearing host_ipi flag 2019-09-24 12:46:26 +10:00
book3s_hv_rm_xive.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
book3s_hv_rmhandlers.S powerpc/kvm: Fix kvmppc_vcore->in_guest value in kvmhv_switch_to_host 2019-10-09 17:16:59 +11:00
book3s_hv_tm_builtin.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_hv_tm.c powerpc updates for 5.3 2019-07-13 16:08:36 -07:00
book3s_hv.c powerpc/64s: Set reserved PCR bits 2019-09-21 08:36:53 +10:00
book3s_interrupts.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_mmu_hpte.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_paired_singles.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_pr_papr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_pr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_rmhandlers.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_rtas.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_segment.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_xics.c scripts/spelling.txt: drop "sepc" from the misspelling list 2019-07-12 11:05:41 -07:00
book3s_xics.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_xive_native.c KVM: PPC: Book3S: Enable XIVE native capability only if OPAL has required functions 2019-08-27 11:45:49 +10:00
book3s_xive_template.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_xive.c powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race 2019-08-16 14:16:59 +10:00
book3s_xive.h powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race 2019-08-16 14:16:59 +10:00
book3s.c kvm: x86, powerpc: do not allow clearing largepages debugfs entry 2019-09-30 18:52:00 +02:00
book3s.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 98 2019-05-24 17:37:54 +02:00
booke_emulate.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
booke_interrupts.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
booke.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
booke.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
bookehv_interrupts.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
e500_emulate.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
e500_mmu_host.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
e500_mmu_host.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
e500_mmu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
e500.c KVM: Assert that struct kvm_vcpu is always as offset zero 2019-08-22 10:09:27 +02:00
e500.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
e500mc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
emulate_loadstore.c Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next 2019-08-23 14:08:04 +10:00
emulate.c Merge remote-tracking branch 'remotes/powerpc/topic/ppc-kvm' into kvm-ppc-next 2019-08-23 14:08:04 +10:00
fpu.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
irq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig powerpc/Kconfig: Clean up formatting 2019-07-04 16:55:10 +10:00
Makefile KVM: PPC: Book3S HV: Add a new KVM device for the XIVE native exploitation mode 2019-04-30 19:35:16 +10:00
mpic.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
powerpc.c PPC KVM update for 5.4 2019-09-10 16:51:17 +02:00
timing.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
timing.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
tm.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
trace_book3s.h KVM: PPC: Book3S: Simplify external interrupt handling 2018-10-09 16:04:27 +11:00
trace_booke.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00
trace_hv.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00
trace_pr.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00
trace.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00