summaryrefslogtreecommitdiff
path: root/Documentation/virtual
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/api.txt18
-rw-r--r--Documentation/virtual/kvm/devices/s390_flic.txt14
2 files changed, 29 insertions, 3 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 4d0542c5206b..a4482cce4bae 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -199,8 +199,8 @@ Type: vm ioctl
Parameters: vcpu id (apic id on x86)
Returns: vcpu fd on success, -1 on error
-This API adds a vcpu to a virtual machine. The vcpu id is a small integer
-in the range [0, max_vcpus).
+This API adds a vcpu to a virtual machine. No more than max_vcpus may be added.
+The vcpu id is an integer in the range [0, max_vcpu_id).
The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of
the KVM_CHECK_EXTENSION ioctl() at run-time.
@@ -212,6 +212,12 @@ cpus max.
If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is
same as the value returned from KVM_CAP_NR_VCPUS.
+The maximum possible value for max_vcpu_id can be retrieved using the
+KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time.
+
+If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that max_vcpu_id
+is the same as the value returned from KVM_CAP_MAX_VCPUS.
+
On powerpc using book3s_hv mode, the vcpus are mapped onto virtual
threads in one or more virtual CPU cores. (This is because the
hardware requires all the hardware threads in a CPU core to be in the
@@ -3788,6 +3794,14 @@ a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace.
Fails if VCPU has already been created, or if the irqchip is already in the
kernel (i.e. KVM_CREATE_IRQCHIP has already been called).
+7.6 KVM_CAP_S390_RI
+
+Architectures: s390
+Parameters: none
+
+Allows use of runtime-instrumentation introduced with zEC12 processor.
+Will return -EINVAL if the machine does not support runtime-instrumentation.
+Will return -EBUSY if a VCPU has already been created.
8. Other capabilities.
----------------------
diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt
index e3e314cb83e8..6b0e115301c8 100644
--- a/Documentation/virtual/kvm/devices/s390_flic.txt
+++ b/Documentation/virtual/kvm/devices/s390_flic.txt
@@ -11,6 +11,7 @@ FLIC provides support to
- add interrupts (KVM_DEV_FLIC_ENQUEUE)
- inspect currently pending interrupts (KVM_FLIC_GET_ALL_IRQS)
- purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS)
+- purge one pending floating I/O interrupt (KVM_DEV_FLIC_CLEAR_IO_IRQ)
- enable/disable for the guest transparent async page faults
- register and modify adapter interrupt sources (KVM_DEV_FLIC_ADAPTER_*)
@@ -40,6 +41,11 @@ Groups:
Simply deletes all elements from the list of currently pending floating
interrupts. No interrupts are injected into the guest.
+ KVM_DEV_FLIC_CLEAR_IO_IRQ
+ Deletes one (if any) I/O interrupt for a subchannel identified by the
+ subsystem identification word passed via the buffer specified by
+ attr->addr (address) and attr->attr (length).
+
KVM_DEV_FLIC_APF_ENABLE
Enables async page faults for the guest. So in case of a major page fault
the host is allowed to handle this async and continues the guest.
@@ -68,7 +74,7 @@ struct kvm_s390_io_adapter {
KVM_DEV_FLIC_ADAPTER_MODIFY
Modifies attributes of an existing I/O adapter interrupt source. Takes
- a kvm_s390_io_adapter_req specifiying the adapter and the operation:
+ a kvm_s390_io_adapter_req specifying the adapter and the operation:
struct kvm_s390_io_adapter_req {
__u32 id;
@@ -94,3 +100,9 @@ struct kvm_s390_io_adapter_req {
KVM_S390_IO_ADAPTER_UNMAP
release a userspace page for the translated address specified in addr
from the list of mappings
+
+Note: The KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR device ioctls executed on
+FLIC with an unknown group or attribute gives the error code EINVAL (instead of
+ENXIO, as specified in the API documentation). It is not possible to conclude
+that a FLIC operation is unavailable based on the error code resulting from a
+usage attempt.