On 07/25/2011 10:08 PM, Anthony Liguori wrote:
+static void as_memory_ioeventfd_add(AddressSpace *as,
MemoryRegionIoeventfd *fd)
+{
+ int r;
+
+ if (!fd->match_data || fd->addr.size != 4) {
+ abort();
+ }
+
+ r = kvm_set_ioeventfd_mmio_long(fd->fd, fd->addr.start,
fd->data, true);
+ if (r< 0) {
+ abort();
+ }
asserts would be friendlier.
I thought asserts were disabled by default. But I see it isn't so; will
update.
I really dislike baking ioeventfd into this API. There is only one
user of ioeventfd in the tree.
Two: virtio-pci and ivshmem.
I worry that by having things like ioeventfd the API, we're making it
too difficult to side-step the API which prevents future optimizations.
I'd prefer virtio-pci to have ugliness in it where it circumvented the
layering vs. having such a device specific thing in generic code.
It's impossible (or at least, impossible without further information
from the API) to do this and retain correctness. Currently virtio-pci
is broken wrt bridges and overlapping BARs; it's probably also broken on
targets that bridge the I/O address space to MMIO.
With the memory API, this is fixed in a natural way by making the I/O
address space a subregion of the bridge which does the conversion; the
code will automatically add the needed offset and use MMIO ioeventfd
instead of portio.
On a more general note, I don't want this to be a lean and mean API that
throws any complexity to the users; instead I want to make writing
devices as simple as possible and own all the smarts.
(an example - undecoded address bits can be specified to the API which
then takes care of replication or shifting).
--
error compiling committee.c: too many arguments to function
