linux/arch/powerpc
Paul Mackerras 884dfb722d KVM: PPC: Book3S HV: Simplify machine check handling
This makes the handling of machine check interrupts that occur inside
a guest simpler and more robust, with less done in assembler code and
in real mode.

Now, when a machine check occurs inside a guest, we always get the
machine check event struct and put a copy in the vcpu struct for the
vcpu where the machine check occurred.  We no longer call
machine_check_queue_event() from kvmppc_realmode_mc_power7(), because
on POWER8, when a vcpu is running on an offline secondary thread and
we call machine_check_queue_event(), that calls irq_work_queue(),
which doesn't work because the CPU is offline, but instead triggers
the WARN_ON(lazy_irq_pending()) in pnv_smp_cpu_kill_self() (which
fires again and again because nothing clears the condition).

All that machine_check_queue_event() actually does is to cause the
event to be printed to the console.  For a machine check occurring in
the guest, we now print the event in kvmppc_handle_exit_hv()
instead.

The assembly code at label machine_check_realmode now just calls C
code and then continues exiting the guest.  We no longer either
synthesize a machine check for the guest in assembly code or return
to the guest without a machine check.

The code in kvmppc_handle_exit_hv() is extended to handle the case
where the guest is not FWNMI-capable.  In that case we now always
synthesize a machine check interrupt for the guest.  Previously, if
the host thinks it has recovered the machine check fully, it would
return to the guest without any notification that the machine check
had occurred.  If the machine check was caused by some action of the
guest (such as creating duplicate SLB entries), it is much better to
tell the guest that it has caused a problem.  Therefore we now always
generate a machine check interrupt for guests that are not
FWNMI-capable.

Reviewed-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-02-21 23:16:44 +11:00
..
boot Kbuild updates for v4.21 2018-12-29 12:03:17 -08:00
configs powerpc/configs: Add PPC4xx_OCM to ppc40x_defconfig 2018-12-30 14:00:47 +11:00
crypto powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
include KVM: PPC: Book3S HV: Simplify machine check handling 2019-02-21 23:16:44 +11:00
kernel jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
kvm KVM: PPC: Book3S HV: Simplify machine check handling 2019-02-21 23:16:44 +11:00
lib Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
math-emu
mm Merge branch 'akpm' (patches from Andrew) 2019-01-05 09:16:18 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-12-10 18:00:43 -08:00
oprofile Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
perf Powerpc/perf: Wire up PMI throttling 2018-12-21 11:32:49 +11:00
platforms cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
purgatory powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
sysdev cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
tools powerpc/tools/checkpatch: Ignore DT_SPLIT_BINDING_PATCH 2018-12-04 19:45:01 +11:00
xmon powerpc/xmon: fix dump_segments() 2018-12-19 18:56:32 +11:00
Kbuild powerpc: Add -Werror at arch/powerpc level 2018-10-19 00:56:17 +11:00
Kconfig Kconfig file consolidation for v4.21 2018-12-29 13:40:29 -08:00
Kconfig.debug powerpc: remove redundant 'default n' from Kconfig-s 2018-10-13 22:21:25 +11:00
Makefile powerpc updates for 4.21 2018-12-27 10:43:24 -08:00
Makefile.postlink