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authorStephen Hemminger <stephen@networkplumber.org>2018-01-09 12:57:31 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-01-10 17:40:53 +0100
commit06028d15177a1b406b7b075ea47c6a352732f23a (patch)
treeef624623dd24296dade2411e85376cfa29d93ab7 /drivers/uio
parente7d214642a19b8e0e7ecda39184c2ab98ba4801f (diff)
uio_hv_generic: check that host supports monitor page
In order for userspace application to signal host, it needs the host to support the monitor page property. Check for the flag and fail if this is not supported. Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/uio')
-rw-r--r--drivers/uio/uio_hv_generic.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index dcd80aad9636..ee6d862ef4bd 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -133,6 +133,13 @@ hv_uio_probe(struct hv_device *dev,
if (ret)
goto fail;
+ /* Communicating with host has to be via shared memory not hypercall */
+ if (!dev->channel->offermsg.monitor_allocated) {
+ dev_err(&dev->device, "vmbus channel requires hypercall\n");
+ ret = -ENOTSUPP;
+ goto fail_close;
+ }
+
dev->channel->inbound.ring_buffer->interrupt_mask = 1;
set_channel_read_mode(dev->channel, HV_CALL_ISR);