uio_hv_generic: Enable interrupt for low speed VMBus devices

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@linux.microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Link: https://lore.kernel.org/r/1711788723-8593-4-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Saurabh Sengar 2024-03-30 01:51:59 -07:00 committed by Greg Kroah-Hartman
parent e566ed5b64
commit 547fa4ffd7

View file

@ -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;
}
@ -240,12 +243,6 @@ hv_uio_probe(struct hv_device *dev,
int ret;
size_t ring_size = hv_dev_ring_size(channel);
/* 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;
}
if (!ring_size)
ring_size = HV_RING_SIZE * PAGE_SIZE;