linux/arch
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
..
alpha treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
arc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
arm Just one ARM fix this time around for Jason Donenfeld, fixing a 2019-06-21 11:11:30 -07:00
arm64 KVM: arm64: Defer guest entry when an asynchronous exception is pending 2019-07-05 13:03:30 +01:00
c6x treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
csky treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
h8300 treewide: Add SPDX license identifier - Kbuild 2019-05-30 11:32:33 -07:00
hexagon treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 267 2019-06-05 17:30:29 +02:00
ia64 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
m68k treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 285 2019-06-05 17:36:37 +02:00
microblaze treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
mips treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 2019-06-19 17:09:56 +02:00
nds32 nds32 patches for 5.2-rc3 2019-06-03 10:23:41 -07:00
nios2 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
openrisc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
parisc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
powerpc powerpc fixes for 5.2 #5 2019-06-22 09:09:42 -07:00
riscv SPDX update for 5.2-rc6 2019-06-21 09:58:42 -07:00
s390 s390/ctl_reg: mark __ctl_set_bit and __ctl_clear_bit as __always_inline 2019-06-11 09:47:10 +02:00
sh treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
sparc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
um treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
unicore32 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
x86 x86/vdso: Prevent segfaults due to hoisted vclock reads 2019-06-21 13:31:52 -07:00
xtensa treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
.gitignore
Kconfig Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-16 11:00:20 -07:00