On 05/20/2016 02:32 AM, Ján Tomko wrote:
On Thu, May 19, 2016 at 05:14:33PM -0400, Laine Stump wrote:
On 05/19/2016 01:23 PM, Ján Tomko wrote:
Yes, qemu_hotplug.c has a few of those places using == DEVICE_ADDRESS_TYPE_PCI untouched by this series. Since they happen after parse is finished, it should be safe.
And anyway, looking at those uses, I think what most of them are doing (calling virDomainPCIAddressEnsureAddr()) is 100% unnecessary, since it's now already done when addresses are assigned in qemuDomainDefAssignAddresses(), which has already been called. Actually, virDomainPCIAddressEnsureAddr is the place where the address gets assigned.
Exactly. But I was looking only at the _CONFIG version of hotplug, and saw that the PCI address had already been assigned by the time we called EnsureAddr, so it was superfluous. I didn't catch the bit that you point out below - in the case of live-only that assignment isn't done.
But only when address == NONE or PCI, which is OK because virDomainPCIAddressEnsureAddr calls PCIAddressIsPresent to decide whether it needs to allocate a new one.
qemuDomainDefAssignAddresses is only called after parsing the whole domain, not just one device.
Cole pushed a patch yesterday to cause it to be called during attach-device as well, but only in the case of _CONFIG, so your point still stands. I guess the patch to remove the other EnsureAddr stuff needs to be combined with moving that AssignAddresses call to a point that is common for live and config (which makes sense - they really do both need the same address)
(Back in Jan 2010 when the calls to qemuDomainPCIAddressEnsureAddr() were added (commit d8acc4), this was not the case - they were needed in order for the new devices to get an address assigned, but a lot has changed since then - even before Cole put in the postparse callback address assignment stuff and called it when attaching a device, we had already been assigning addresses during the higher level qemuDomainAttachDeviceConfig for a long time (since commit f5dd58a in June 2012; qemuDomainAttachDeviceConfig is for changing the persistent definition. Hotplug in qemuDomainAttachDeviceLive does not call any other address assignment function.
Yeah, I missed that in my haste.