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| author | James Morse <james.morse@arm.com> | 2020-01-21 12:33:55 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-01-23 10:38:15 +0000 |
| commit | 018f22f95e8a6c3e27188b7317ef2c70a34cb2cd (patch) | |
| tree | 7fc9466d8d9f75a168b56562429892f6e0ec2eb1 /virt | |
| parent | cf2d23e0bac9f6b5cd1cba8898f5f05ead40e530 (diff) | |
| download | linux-018f22f95e8a6c3e27188b7317ef2c70a34cb2cd.tar.bz2 | |
KVM: arm: Fix DFSR setting for non-LPAE aarch32 guests
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: 74a64a981662a ("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
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/arm/aarch32.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/virt/kvm/arm/aarch32.c b/virt/kvm/arm/aarch32.c index 631d397ac81b..2da482ca7067 100644 --- a/virt/kvm/arm/aarch32.c +++ b/virt/kvm/arm/aarch32.c @@ -181,10 +181,12 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, /* Give the guest an IMPLEMENTATION DEFINED exception */ is_lpae = (vcpu_cp15(vcpu, c2_TTBCR) >> 31); - if (is_lpae) + if (is_lpae) { *fsr = 1 << 9 | 0x34; - else - *fsr = 0x14; + } else { + /* Surprise! DFSR's FS[4] lives in bit 10 */ + *fsr = BIT(10) | 0x4; /* 0x14 */ + } } void kvm_inject_dabt32(struct kvm_vcpu *vcpu, unsigned long addr) |