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| author | Marc Zyngier <maz@kernel.org> | 2024-04-23 18:05:38 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2024-05-01 18:48:15 +0300 |
| commit | 3b467b16582c077f57fab244cf0801ecea7914b6 (patch) | |
| tree | 7fac3ad014f2176391f944236320c9801a1a8ed0 /arch/arm64/kvm | |
| parent | 92536992cfd461207c78e46154d16050b236a6fc (diff) | |
| download | linux-3b467b16582c077f57fab244cf0801ecea7914b6.tar.xz | |
KVM: arm64: Force injection of a data abort on NISV MMIO exit
If a vcpu exits for a data abort with an invalid syndrome, the
expectations are that userspace has a chance to save the day if
it has requested to see such exits.
However, this is completely futile in the case of a protected VM,
as none of the state is available. In this particular case, inject
a data abort directly into the vcpu, consistent with what userspace
could do.
This also helps with pKVM, which discards all syndrome information when
forwarding data aborts that are not known to be MMIO.
Finally, document this tweak to the API.
Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240423150538.2103045-31-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm')
| -rw-r--r-- | arch/arm64/kvm/mmio.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c index 5e1ffb0d5363..cd6b7b83e2c3 100644 --- a/arch/arm64/kvm/mmio.c +++ b/arch/arm64/kvm/mmio.c @@ -133,11 +133,19 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) /* * No valid syndrome? Ask userspace for help if it has * volunteered to do so, and bail out otherwise. + * + * In the protected VM case, there isn't much userspace can do + * though, so directly deliver an exception to the guest. */ if (!kvm_vcpu_dabt_isvalid(vcpu)) { trace_kvm_mmio_nisv(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu), kvm_vcpu_get_hfar(vcpu), fault_ipa); + if (vcpu_is_protected(vcpu)) { + kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu)); + return 1; + } + if (test_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER, &vcpu->kvm->arch.flags)) { run->exit_reason = KVM_EXIT_ARM_NISV; |