Commit 9b0d721a authored Jan 12, 2016 by David Hildenbrand Committed by Christian Borntraeger Feb 10, 2016

KVM: s390: instruction-fetching exceptions on SIE faults

On instruction-fetch exceptions, we have to forward the PSW by any
valid ilc and correctly use that ilc when injecting the irq. Injection
will already take care of rewinding the PSW if we injected a nullifying
program irq, so we don't need special handling prior to injection.

Until now, autodetection would have guessed an ilc of 0.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

parent 56317920

arch/s390/kvm/kvm-s390.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -2181,9 +2181,17 @@ static int vcpu_post_run_fault_in_sie(struct kvm_vcpu *vcpu)
		* to be able to forward the PSW.
		*/
		rc = read_guest_instr(vcpu, &opcode, 1);
		if (rc)
		return kvm_s390_inject_prog_cond(vcpu, rc);
		ilen = insn_length(opcode);
		if (rc < 0) {
		return rc;
		} else if (rc) {
		/* Instruction-Fetching Exceptions - we can't detect the ilen.
		* Forward by arbitrary ilc, injection will take care of
		* nullification if necessary.
		*/
		pgm_info = vcpu->arch.pgm;
		ilen = 4;
		}
		pgm_info.flags = ilen \| KVM_S390_PGM_FLAGS_ILC_VALID;
		kvm_s390_forward_psw(vcpu, ilen);
		return kvm_s390_inject_prog_irq(vcpu, &pgm_info);

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