| From b938eacea0b6881f2116a061e6da3ec840e75137 Mon Sep 17 00:00:00 2001 |
| From: David Hildenbrand <dahi@linux.vnet.ibm.com> |
| Date: Thu, 30 Apr 2015 13:33:59 +0200 |
| Subject: KVM: s390: fix external call injection without sigp interpretation |
| |
| From: David Hildenbrand <dahi@linux.vnet.ibm.com> |
| |
| commit b938eacea0b6881f2116a061e6da3ec840e75137 upstream. |
| |
| Commit ea5f49692575 ("KVM: s390: only one external call may be pending |
| at a time") introduced a bug on machines that don't have SIGP |
| interpretation facility installed. |
| The injection of an external call will now always fail with -EBUSY |
| (if none is already pending). |
| |
| This leads to the following symptoms: |
| - An external call will be injected but with the wrong "src cpu id", |
| as this id will not be remembered. |
| - The target vcpu will not be woken up, therefore the guest will hang if |
| it cannot deal with unexpected failures of the SIGP EXTERNAL CALL |
| instruction. |
| - If an external call is already pending, -EBUSY will not be reported. |
| |
| Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> |
| Reviewed-by: Jens Freimann <jfrei@linux.vnet.ibm.com> |
| Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> |
| Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| arch/s390/kvm/interrupt.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/arch/s390/kvm/interrupt.c |
| +++ b/arch/s390/kvm/interrupt.c |
| @@ -1061,7 +1061,7 @@ static int __inject_extcall(struct kvm_v |
| if (sclp_has_sigpif()) |
| return __inject_extcall_sigpif(vcpu, src_id); |
| |
| - if (!test_and_set_bit(IRQ_PEND_EXT_EXTERNAL, &li->pending_irqs)) |
| + if (test_and_set_bit(IRQ_PEND_EXT_EXTERNAL, &li->pending_irqs)) |
| return -EBUSY; |
| *extcall = irq->u.extcall; |
| atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags); |
