android_kernel_motorola_sm6225/virt
James Morse 8ea83328b2 KVM: arm: Fix DFSR setting for non-LPAE aarch32 guests
commit 018f22f95e8a6c3e27188b7317ef2c70a34cb2cd upstream.

Beata reports that KVM_SET_VCPU_EVENTS doesn't inject the expected
exception to a non-LPAE aarch32 guest.

The host intends to inject DFSR.FS=0x14 "IMPLEMENTATION DEFINED fault
(Lockdown fault)", but the guest receives DFSR.FS=0x04 "Fault on
instruction cache maintenance". This fault is hooked by
do_translation_fault() since ARMv6, which goes on to silently 'handle'
the exception, and restart the faulting instruction.

It turns out, when TTBCR.EAE is clear DFSR is split, and FS[4] has
to shuffle up to DFSR[10].

As KVM only does this in one place, fix up the static values. We
now get the expected:
| Unhandled fault: lock abort (0x404) at 0x9c800f00

Fixes: 74a64a9816 ("KVM: arm/arm64: Unify 32bit fault injection")
Reported-by: Beata Michalska <beata.michalska@linaro.org>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200121123356.203000-2-james.morse@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14 16:33:26 -05:00
..
kvm KVM: arm: Fix DFSR setting for non-LPAE aarch32 guests 2020-02-14 16:33:26 -05:00
lib KVM: eventfd: fix NULL deref irqbypass consumer 2017-01-12 14:42:34 +01:00
Makefile