From ca3cda6fcf1e922213a0cc58e708ffb999151db3 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 9 Jan 2018 12:57:32 -0800 Subject: uio_hv_generic: add rescind support When host rescinds the device, the UIO driver will clear the interrupt state and notify application. The read (or write) on the interrupt FD will then fail with -EIO. This is simpler than adding lots extra uevent stuff inside UIO. Signed-off-by: Stephen Hemminger Signed-off-by: Greg Kroah-Hartman --- Documentation/driver-api/uio-howto.rst | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'Documentation') diff --git a/Documentation/driver-api/uio-howto.rst b/Documentation/driver-api/uio-howto.rst index 97e6435b3934..693e3bd84e79 100644 --- a/Documentation/driver-api/uio-howto.rst +++ b/Documentation/driver-api/uio-howto.rst @@ -698,6 +698,10 @@ prevents the device from generating further interrupts until the bit is cleared. The userspace driver should clear this bit before blocking and waiting for more interrupts. +When host rescinds a device, the interrupt file descriptor is marked down +and any reads of the interrupt file descriptor will return -EIO. Similar +to a closed socket or disconnected serial device. + The vmbus device regions are mapped into uio device resources: 0) Channel ring buffers: guest to host and host to guest 1) Guest to host interrupt signalling pages -- cgit v1.2.3