Commit 022c8328 authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier
Browse files

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: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarMarc 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
parent 54dc0d24

arch/arm64/kvm/mmio.c

+0 −6
Original line number Diff line number Diff line
@@ -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

arch/arm64/kvm/mmu.c

+12 −1
Original line number Diff line number Diff line
@@ -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

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