diff options
| author | Eric Farman <farman@linux.ibm.com> | 2021-12-13 22:05:50 +0100 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@linux.ibm.com> | 2021-12-17 14:52:47 +0100 |
| commit | 812de04661c4daa7ac385c0dfd62594540538034 (patch) | |
| tree | 07fa0f43cd2559ffffe0773bc67de4713da9abdf /arch/s390/kvm/interrupt.c | |
| parent | 3c724f1a1caaee40c99422e22e22133e1496ffc3 (diff) | |
KVM: s390: Clarify SIGP orders versus STOP/RESTART
With KVM_CAP_S390_USER_SIGP, there are only five Signal Processor
orders (CONDITIONAL EMERGENCY SIGNAL, EMERGENCY SIGNAL, EXTERNAL CALL,
SENSE, and SENSE RUNNING STATUS) which are intended for frequent use
and thus are processed in-kernel. The remainder are sent to userspace
with the KVM_CAP_S390_USER_SIGP capability. Of those, three orders
(RESTART, STOP, and STOP AND STORE STATUS) have the potential to
inject work back into the kernel, and thus are asynchronous.
Let's look for those pending IRQs when processing one of the in-kernel
SIGP orders, and return BUSY (CC2) if one is in process. This is in
agreement with the Principles of Operation, which states that only one
order can be "active" on a CPU at a time.
Cc: stable@vger.kernel.org
Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20211213210550.856213-2-farman@linux.ibm.com
[borntraeger@linux.ibm.com: add stable tag]
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Diffstat (limited to 'arch/s390/kvm/interrupt.c')
| -rw-r--r-- | arch/s390/kvm/interrupt.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index c3bd993fdd0c..0576d5c99138 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -2115,6 +2115,13 @@ int kvm_s390_is_stop_irq_pending(struct kvm_vcpu *vcpu) return test_bit(IRQ_PEND_SIGP_STOP, &li->pending_irqs); } +int kvm_s390_is_restart_irq_pending(struct kvm_vcpu *vcpu) +{ + struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int; + + return test_bit(IRQ_PEND_RESTART, &li->pending_irqs); +} + void kvm_s390_clear_stop_irq(struct kvm_vcpu *vcpu) { struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int; |