On 14/02/2019 13:14, Pierre Morel wrote:
A new CPU model facilities is introduced to support AP devices
interruption interception for a KVM guest.
"APQI" for "AP-Queue Interruption" facility
The S390_FEAT_AP_QUEUE_INTERRUPT_CONTROL, CPU facility indicates
whether the PQAP instruction with the AQIC command is available
to the guest.
This feature will be enabled only if the AP instructions are
available on the linux host and AQIC facility is installed on
the host.
This feature must be turned on from userspace to intercept AP
instructions on the KVM guest. The QEMU command line to turn
this feature on looks something like this:
qemu-system-s390x ... -cpu xxx,apqi=on ...
Hi,
I suddenly have a very big doubt on this QEMU patch.
Older Linux advertise PQAP/AQIC feature (65)
Older Qemu mask it for the guest
Now if we set aqic = on in the new QEMU,
QEMU advertises feature (65)
The guest gets an OPERATION EXCEPTION even we advertised the feature 65.
This seems wrong to me, we should verify that the vfio_driver is loaded
in the host before starting the guest with something like:
kvm_vm_check_attr(kvm_state, KVM_S390_VM_ENABLE_AQIC)
Don't you think?
Regards,
Pierre
Signed-off-by: Pierre Morel <pmo...@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrow...@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntrae...@de.ibm.com>
Reviewed-by: Halil Pasic <pa...@linux.ibm.com>
---
target/s390x/cpu_features.c | 1 +
target/s390x/cpu_features_def.h | 1 +
target/s390x/cpu_models.c | 1 +
target/s390x/gen-features.c | 1 +
4 files changed, 4 insertions(+)
diff --git a/target/s390x/cpu_features.c b/target/s390x/cpu_features.c
index 60cfeba..99bd382 100644
--- a/target/s390x/cpu_features.c
+++ b/target/s390x/cpu_features.c
@@ -84,6 +84,7 @@ static const S390FeatDef s390_features[] = {
FEAT_INIT("sema", S390_FEAT_TYPE_STFL, 59, "Semaphore-assist facility"),
FEAT_INIT("tsi", S390_FEAT_TYPE_STFL, 60, "Time-slice Instrumentation
facility"),
FEAT_INIT("ri", S390_FEAT_TYPE_STFL, 64, "CPU runtime-instrumentation
facility"),
+ FEAT_INIT("apqi", S390_FEAT_TYPE_STFL, 65, "AP-Queue interruption
facility"),
FEAT_INIT("zpci", S390_FEAT_TYPE_STFL, 69, "z/PCI facility"),
FEAT_INIT("aen", S390_FEAT_TYPE_STFL, 71,
"General-purpose-adapter-event-notification facility"),
FEAT_INIT("ais", S390_FEAT_TYPE_STFL, 72,
"General-purpose-adapter-interruption-suppression facility"),
diff --git a/target/s390x/cpu_features_def.h b/target/s390x/cpu_features_def.h
index 5fc7e7b..3f22780 100644
--- a/target/s390x/cpu_features_def.h
+++ b/target/s390x/cpu_features_def.h
@@ -72,6 +72,7 @@ typedef enum {
S390_FEAT_SEMAPHORE_ASSIST,
S390_FEAT_TIME_SLICE_INSTRUMENTATION,
S390_FEAT_RUNTIME_INSTRUMENTATION,
+ S390_FEAT_AP_QUEUE_INTERRUPT_CONTROL,
S390_FEAT_ZPCI,
S390_FEAT_ADAPTER_EVENT_NOTIFICATION,
S390_FEAT_ADAPTER_INT_SUPPRESSION,
diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
index 7c253ff..6b5e94b 100644
--- a/target/s390x/cpu_models.c
+++ b/target/s390x/cpu_models.c
@@ -788,6 +788,7 @@ static void check_consistency(const S390CPUModel *model)
{ S390_FEAT_SIE_KSS, S390_FEAT_SIE_F2 },
{ S390_FEAT_AP_QUERY_CONFIG_INFO, S390_FEAT_AP },
{ S390_FEAT_AP_FACILITIES_TEST, S390_FEAT_AP },
+ { S390_FEAT_AP_QUEUE_INTERRUPT_CONTROL, S390_FEAT_AP },
};
int i;
diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
index 70015ea..b051221 100644
--- a/target/s390x/gen-features.c
+++ b/target/s390x/gen-features.c
@@ -448,6 +448,7 @@ static uint16_t full_GEN12_GA1[] = {
S390_FEAT_EDAT_2,
S390_FEAT_SIDE_EFFECT_ACCESS_ESOP2,
S390_FEAT_AP_QUERY_CONFIG_INFO,
+ S390_FEAT_AP_QUEUE_INTERRUPT_CONTROL,
S390_FEAT_AP_FACILITIES_TEST,
S390_FEAT_AP,
};
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
