linux/arch/arm64/kvm
James Morse 5dcd0fdbb4 KVM: arm64: Defer guest entry when an asynchronous exception is pending
SError that occur during world-switch's entry to the guest will be
accounted to the guest, as the exception is masked until we enter the
guest... but we want to attribute the SError as precisely as possible.

Reading DISR_EL1 before guest entry requires free registers, and using
ESB+DISR_EL1 to consume and read back the ESR would leave KVM holding
a host SError... We would rather leave the SError pending and let the
host take it once we exit world-switch. To do this, we need to defer
guest-entry if an SError is pending.

Read the ISR to see if SError (or an IRQ) is pending. If so fake an
exit. Place this check between __guest_enter()'s save of the host
registers, and restore of the guest's. SError that occur between
here and the eret into the guest must have affected the guest's
registers, which we can naturally attribute to the guest.

The dsb is needed to ensure any previous writes have been done before
we read ISR_EL1. On systems without the v8.2 RAS extensions this
doesn't give us anything as we can't contain errors, and the ESR bits
to describe the severity are all implementation-defined. Replace
this with a nop for these systems.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-07-05 13:03:30 +01:00
..
hyp KVM: arm64: Defer guest entry when an asynchronous exception is pending 2019-07-05 13:03:30 +01:00
debug.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
fpsimd.c KVM: arm64/sve: Context switch the SVE registers 2019-03-29 14:41:53 +00:00
guest.c SPDX update for 5.2-rc6 2019-06-21 09:58:42 -07:00
handle_exit.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
hyp-init.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
hyp.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
inject_fault.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
irq.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 422 2019-06-05 17:37:15 +02:00
Kconfig Make anon_inodes unconditional 2019-04-19 14:03:11 +02:00
Makefile arm64: KVM: Add accessors to track guest/host only counters 2019-04-24 15:35:30 +01:00
pmu.c KVM: arm64: Move pmu hyp code under hyp's Makefile to avoid instrumentation 2019-05-24 14:53:20 +01:00
regmap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
reset.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
sys_regs_generic_v8.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
sys_regs.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
sys_regs.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
trace.h arm64: KVM: Add trapped system register access tracepoint 2018-12-19 17:47:08 +00:00
va_layout.c KVM: arm64: Abstract the size of the HYP vectors pre-amble 2019-07-05 13:03:29 +01:00
vgic-sys-reg-v3.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00