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KVM: arm64: Move S1PTW S2 fault logic out of io_mem_abort() 

To allow for re-injection of stage-2 faults on stage-1 page-table walks
due to either a missing or read-only memslot, move the triage logic out
of io_mem_abort() and into kvm_handle_guest_abort(), where these aborts
can be handled before anything else.

Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200729102821.23392-5-will@kernel.org
zero-sugar-mainline-defconfig
Will Deacon 2020-07-29 11:28:21 +01:00 committed by Marc Zyngier
parent 54dc0d2404
commit 022c8328dc
2 changed files with 12 additions and 7 deletions
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6
arch/arm64/kvm/mmio.c
View File

@ -145,12 +145,6 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
return -ENOSYS;
}
/* Page table accesses IO mem: tell guest to fix its TTBR */
if (kvm_vcpu_dabt_iss1tw(vcpu)) {
kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
return 1;
}
/*
* Prepare MMIO operation. First decode the syndrome data we get
* from the CPU. Then try if some in-kernel emulation feels

13
arch/arm64/kvm/mmu.c
View File

@ -2105,12 +2105,23 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
write_fault = kvm_is_write_fault(vcpu);
if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
/*
* The guest has put either its instructions or its page-tables
* somewhere it shouldn't have. Userspace won't be able to do
* anything about this (there's no syndrome for a start), so
* re-inject the abort back into the guest.
*/
if (is_iabt) {
/* Prefetch Abort on I/O address */
ret = -ENOEXEC;
goto out;
}
if (kvm_vcpu_dabt_iss1tw(vcpu)) {
kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
ret = 1;
goto out_unlock;
}
/*
* Check for a cache maintenance operation. Since we
* ended-up here, we know it is outside of any memory