Merge tag 'kvms390-20160420' of...

Merge tag 'kvms390-20160420' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into next

KVM/s390 patches for 4.7:
- improve perf output
- cleanup and a new feature in the floating interrupt controller (FLIC)

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.
@@ -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.

arch/s390/include/uapi/asm/kvm.h

@@ -25,6 +25,7 @@
 #define KVM_DEV_FLIC_APF_DISABLE_WAIT	5
 #define KVM_DEV_FLIC_ADAPTER_REGISTER	6
 #define KVM_DEV_FLIC_ADAPTER_MODIFY	7
+#define KVM_DEV_FLIC_CLEAR_IO_IRQ	8
 /*
  * We can have up to 4*64k pending subchannels + 8 adapter interrupts,
  * as well as up  to ASYNC_PF_PER_VCPU*KVM_MAX_VCPUS pfault done interrupts.

arch/s390/include/uapi/asm/sie.h

@@ -16,14 +16,19 @@
 	{ 0x01, "SIGP sense" },					\
 	{ 0x02, "SIGP external call" },				\
 	{ 0x03, "SIGP emergency signal" },			\
+	{ 0x04, "SIGP start" },					\
 	{ 0x05, "SIGP stop" },					\
 	{ 0x06, "SIGP restart" },				\
 	{ 0x09, "SIGP stop and store status" },			\
 	{ 0x0b, "SIGP initial cpu reset" },			\
+	{ 0x0c, "SIGP cpu reset" },				\
 	{ 0x0d, "SIGP set prefix" },				\
 	{ 0x0e, "SIGP store status at address" },		\
 	{ 0x12, "SIGP set architecture" },			\
-	{ 0x15, "SIGP sense running" }
+	{ 0x13, "SIGP conditional emergency signal" },		\
+	{ 0x15, "SIGP sense running" },				\
+	{ 0x16, "SIGP set multithreading"},			\
+	{ 0x17, "SIGP store additional status ait address"}
 
 #define icpt_prog_codes						\
 	{ 0x0001, "Prog Operation" },				\

arch/s390/kvm/interrupt.c

@@ -2034,6 +2034,27 @@ static int modify_io_adapter(struct kvm_device *dev,
 	return ret;
 }
 
+static int clear_io_irq(struct kvm *kvm, struct kvm_device_attr *attr)
+
+{
+	const u64 isc_mask = 0xffUL << 24; /* all iscs set */
+	u32 schid;
+
+	if (attr->flags)
+		return -EINVAL;
+	if (attr->attr != sizeof(schid))
+		return -EINVAL;
+	if (copy_from_user(&schid, (void __user *) attr->addr, sizeof(schid)))
+		return -EFAULT;
+	kfree(kvm_s390_get_io_int(kvm, isc_mask, schid));
+	/*
+	 * If userspace is conforming to the architecture, we can have at most
+	 * one pending I/O interrupt per subchannel, so this is effectively a
+	 * clear all.
+	 */
+	return 0;
+}
+
 static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 {
 	int r = 0;
@@ -2067,6 +2088,9 @@ static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 	case KVM_DEV_FLIC_ADAPTER_MODIFY:
 		r = modify_io_adapter(dev, attr);
 		break;
+	case KVM_DEV_FLIC_CLEAR_IO_IRQ:
+		r = clear_io_irq(dev->kvm, attr);
+		break;
 	default:
 		r = -EINVAL;
 	}
@@ -2074,6 +2098,23 @@ static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
 	return r;
 }
 
+static int flic_has_attr(struct kvm_device *dev,
+			     struct kvm_device_attr *attr)
+{
+	switch (attr->group) {
+	case KVM_DEV_FLIC_GET_ALL_IRQS:
+	case KVM_DEV_FLIC_ENQUEUE:
+	case KVM_DEV_FLIC_CLEAR_IRQS:
+	case KVM_DEV_FLIC_APF_ENABLE:
+	case KVM_DEV_FLIC_APF_DISABLE_WAIT:
+	case KVM_DEV_FLIC_ADAPTER_REGISTER:
+	case KVM_DEV_FLIC_ADAPTER_MODIFY:
+	case KVM_DEV_FLIC_CLEAR_IO_IRQ:
+		return 0;
+	}
+	return -ENXIO;
+}
+
 static int flic_create(struct kvm_device *dev, u32 type)
 {
 	if (!dev)
@@ -2095,6 +2136,7 @@ struct kvm_device_ops kvm_flic_ops = {
 	.name = "kvm-flic",
 	.get_attr = flic_get_attr,
 	.set_attr = flic_set_attr,
+	.has_attr = flic_has_attr,
 	.create = flic_create,
 	.destroy = flic_destroy,
 };