Commit 3bda7f0a authored by Mark Cave-Ayland's avatar Mark Cave-Ayland Committed by Paul Mackerras
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KVM: PPC: Book3S PR: Fix software breakpoints 



QEMU's kvm_handle_debug() function identifies software breakpoints by checking
for a value of 0 in kvm_debug_exit_arch's status field. Since this field isn't
explicitly set to 0 when the software breakpoint instruction is detected, any
previous non-zero value present causes a hang in QEMU as it tries to process
the breakpoint instruction incorrectly as a hardware breakpoint.

Ensure that the kvm_debug_exit_arch status field is set to 0 when the software
breakpoint instruction is detected (similar to the existing logic in booke.c
and e500_emulate.c) to restore software breakpoint functionality under Book3S
PR.

Signed-off-by: default avatarMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: default avatarFabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent 0e84ec96

arch/powerpc/kvm/emulate.c

+1 −0
Original line number Diff line number Diff line
@@ -282,6 +282,7 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu) 
		 */

		if (inst == KVMPPC_INST_SW_BREAKPOINT) {

			run->exit_reason = KVM_EXIT_DEBUG;

			run->debug.arch.status = 0;

			run->debug.arch.address = kvmppc_get_pc(vcpu);

			emulated = EMULATE_EXIT_USER;

			advance = 0;