Re: [libvirt] [PATCH 1/2] conf: new function virDomainPCIAddressSetAllMulti()
On Tue, 2017-01-10 at 03:23 -0500, Laine Stump wrote:
This utility function looks through a virPCIAddressSet for any slot
of
any bus that has multiple functions in use, and sets the "multi" flag
in the virDomainDeviceInfo for the device that is assigned to function
0 of that slot (as long as it hasn't already been set explicitly by
someone who presumably has better information than we do).
It isn't yet called from anywhere, so will have no functional effect.
[...]
+static int
+virDomainPCIAddressSetMultiIter(virDomainDefPtr def ATTRIBUTE_UNUSED,
+ virDomainDeviceDefPtr dev ATTRIBUTE_UNUSED,
+ virDomainDeviceInfoPtr info,
+ void *data)
virDomainPCIAddressSetAllMultiIter()?
Or not :)
[...]
+/**
+ * virDomainPCIAddressSetAllMulti():
+ *
+ * @def: the domain definition whose devices may need adjusting
+ * @addrs: address set keeping track of all addresses in use.
+ *
+ * Look for any PCI slots that have multiple functions assigned, and
+ * set multi to YES in the address for the device at function 0
s/YES/ON/
+ * (unless it has been explicitly set to NO).
s/NO/OFF/
+ *
+ * No return code, since there is no possibility of failure.
+ */
+void
+virDomainPCIAddressSetAllMulti(virDomainDefPtr def,
+ virDomainPCIAddressSetPtr addrs)
I also just realized that virDomainPCIAddressSetAllMulti()
might be mistaken for vir::DomainPCIAddressSet::AllMulti()
instead of vir::Domain::PCIAddressSetAllMulti().
The joys of pretending to use an object-oriented language
when actually all you have is plain old C :)
+{
+ /* Scan through all the slots in @addrs looking for any that have
+ * more than just function 0 marked as in use, then use an
+ * iterator to find the DeviceInfo that uses function 0 on that
+ * slot and mark it as multi = YES
s/YES/ON/
+ */
+ size_t busIdx, slotIdx;
+
+ for (busIdx = 0; busIdx < addrs->nbuses; busIdx++) {
+ virDomainPCIAddressBusPtr bus = &addrs->buses[busIdx];
+
+ for (slotIdx = bus->minSlot; slotIdx <= bus->maxSlot; slotIdx++) {
+ if (bus->slot[slotIdx].functions > 1) {
+ virPCIDeviceAddress addr = { .domain = 0,
This doesn't look right. What happens if the multifunction
device is at eg. 0001:00:04.0?
...
Oh, never mind, apparently virDomainPCIAddressSet has no
concept of PCI domains anyways... So that's an existing
limitation - one that I assume we're going to have to
address, especially now that ppc64 guests are going to
want to use *lots* of separate PCI domains.
On the other hand, at the point where you're going to call
this function haven't PCI addresses already been assigned
and stored in @def? Why not iterate over it twice to make
the comparison future-proof? The computational cost would
be the same AFAICT.
--
Andrea Bolognani / Red Hat / Virtualization