KVM: s390: introduce ais mode modify function
Provide an interface for userspace to modify AIS
(adapter-interruption-suppression) mode state, and add documentation
for the interface. Allowed target modes are ALL-Interruptions mode
and SINGLE-Interruption mode.
We introduce the 'simm' and 'nimm' fields in kvm_s390_float_interrupt
to store interruption modes for each ISC. Each bit in 'simm' and
'nimm' targets to one ISC, and collaboratively indicate three modes:
ALL-Interruptions, SINGLE-Interruption and NO-Interruptions. This
interface can initiate most transitions between the states; transition
from SINGLE-Interruption to NO-Interruptions via adapter interrupt
injection will be introduced in a following patch. The meaningful
combinations are as follows:
interruption mode | simm bit | nimm bit
------------------|----------|----------
ALL | 0 | 0
SINGLE | 1 | 0
NO | 1 | 1
Besides, add tracepoint to track AIS mode transitions.
Co-Authored-By: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: Fei Li <sherrylf@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 499c72c..552c319 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -521,6 +521,12 @@
#define FIRQ_CNTR_PFAULT 3
#define FIRQ_MAX_COUNT 4
+/* mask the AIS mode for a given ISC */
+#define AIS_MODE_MASK(isc) (0x80 >> isc)
+
+#define KVM_S390_AIS_MODE_ALL 0
+#define KVM_S390_AIS_MODE_SINGLE 1
+
struct kvm_s390_float_interrupt {
unsigned long pending_irqs;
spinlock_t lock;
@@ -530,6 +536,10 @@
struct kvm_s390_ext_info srv_signal;
int next_rr_cpu;
unsigned long idle_mask[BITS_TO_LONGS(KVM_MAX_VCPUS)];
+ struct mutex ais_lock;
+ u8 simm;
+ u8 nimm;
+ int ais_enabled;
};
struct kvm_hw_wp_info_arch {