Hyper-V is adding some "specialty" synthetic devices. Instead of writing
new kernel-level VMBus drivers for these devices, the devices will be
presented to user space via this existing Hyper-V generic UIO driver, so
that a user space driver can handle the device. Since these new synthetic
devices are low speed devices, they don't support monitor bits and we must
use vmbus_setevent() to enable interrupts from the host.
Signed-off-by: Saurabh Sengar <ssengar@xxxxxxxxxxxxxxxxxxx>
---
drivers/uio/uio_hv_generic.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index c08a6cfd119f..8e5aa4a1247f 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -84,6 +84,9 @@ hv_uio_irqcontrol(struct uio_info *info, s32 irq_state)
dev->channel->inbound.ring_buffer->interrupt_mask = !irq_state;
virt_mb();
+ if (!dev->channel->offermsg.monitor_allocated && irq_state)
+ vmbus_setevent(dev->channel);
+
return 0;
}
@@ -239,12 +242,6 @@ hv_uio_probe(struct hv_device *dev,
void *ring_buffer;
int ret;
- /* Communicating with host has to be via shared memory not hypercall */
- if (!channel->offermsg.monitor_allocated) {
- dev_err(&dev->device, "vmbus channel requires hypercall\n");
- return -ENOTSUPP;
- }
-
pdata = devm_kzalloc(&dev->device, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
--
2.34.1
