On Tue, Mar 9, 2010 at 10:28 AM, Avi Kivity<address@hidden> wrote:
On 03/09/2010 05:27 PM, Cam Macdonell wrote:
Registers are used
for synchronization between guests sharing the same memory object when
interrupts are supported (this requires using the shared memory server).
How does the driver detect whether interrupts are supported or not?
At the moment, the VM ID is set to -1 if interrupts aren't supported,
but that may not be the clearest way to do things. With UIO is there
a way to detect if the interrupt pin is on?
I suggest not designing the device to uio. Make it a good guest-independent
device, and if uio doesn't fit it, change it.
Why not support interrupts unconditionally? Is the device useful without
interrupts?
Currently my patch works with or without the shared memory server. If
you give the parameter
-ivshmem 256,foo
then this will create (if necessary) and map /dev/shm/foo as the
shared region without interrupt support. Some users of shared memory
are using it this way.
Going forward we can require the shared memory server and always have
interrupts enabled.