On 11/10/2021 1:12 PM, Annie.li wrote:
On 11/9/2021 1:32 PM, Daniel P. Berrangé wrote:
On Tue, Nov 09, 2021 at 12:01:30PM -0500, Annie.li wrote:
On 11/9/2021 6:19 AM, Daniel P. Berrangé wrote:
On Tue, Nov 09, 2021 at 04:40:10PM +0530, Ani Sinha wrote:
On Tue, Nov 9, 2021 at 3:23 PM Daniel P. Berrangé
<berra...@redhat.com> wrote:
On Tue, Nov 09, 2021 at 12:41:39PM +0530, Ani Sinha wrote:
+gerd
On Mon, 8 Nov 2021, Annie.li wrote:
Update:
I've tested q35 guest w/o OVMF, the APCI PCI hot-plugging works
well in q35
guest. Seems this issue only happens in q35 guest w/ OVMF.
Looks that there is already a bug filed against this hotplug
issue in q35
guest w/ OVMF,
https://urldefense.com/v3/__https://bugzilla.redhat.com/show_bug.cgi?id=2004829__;!!ACWV5N9M2RV99hQ!bCogoVXfTRaTu03Bg6dQ8NrSINSha4iSSLuZJerOTVdIdWnu1msYwJ8E_c_jRg$
In this bug, it is recommended to add "-global
ICH9-LPC.acpi-pci-hotplug-with-bridge-support=off \" on qemu
command for 6.1.
However, with this option for 6.1(PCIe native hotplug), there
still are kinds
of issues. For example, one of them is the deleted virtio_blk
device still
shows in the Device Manager in Windows q35 guest, the operation
of re-scanning
new hardware takes forever there. This means both PCIe native
hotplug and ACPI
hotplug all have issues in q35 guests.
This is sad.
Per comments in this bug, changes in both OVMF and QEMU are
necessary to
support ACPI hot plug in q35 guest. The fixes may likely be
available in QEMU
6.2.0.
So we are in soft code freeze for 6.2:
https://urldefense.com/v3/__https://wiki.qemu.org/Planning/6.2__;!!ACWV5N9M2RV99hQ!bCogoVXfTRaTu03Bg6dQ8NrSINSha4iSSLuZJerOTVdIdWnu1msYwJ_pKO8AzA$
I am curious about Gerd's comment #10:
"The 6.2 rebase should make hotplug work
again with the default configuration."
Sadly I have not seen any public discussion on what we want to do
for the issues with acpi hotplug for bridges in q35.
I've raised one of the problems a week ago and there's a promised
fix
https://urldefense.com/v3/__https://lists.gnu.org/archive/html/qemu-devel/2021-11/msg00558.html__;!!ACWV5N9M2RV99hQ!bCogoVXfTRaTu03Bg6dQ8NrSINSha4iSSLuZJerOTVdIdWnu1msYwJ-np8GcUA$
So
https://urldefense.com/v3/__https://gitlab.com/qemu-project/qemu/-/issues/641__;!!ACWV5N9M2RV99hQ!bCogoVXfTRaTu03Bg6dQ8NrSINSha4iSSLuZJerOTVdIdWnu1msYwJ86xk2gtg$
is the same as
https://urldefense.com/v3/__https://bugzilla.redhat.com/show_bug.cgi?id=2006409__;!!ACWV5N9M2RV99hQ!bCogoVXfTRaTu03Bg6dQ8NrSINSha4iSSLuZJerOTVdIdWnu1msYwJ9crT9JKw$
isn't it?
Yes, one upstream, one downstream.
Thanks for the info.
So q35 guests with either OVMF or SeaBIOS have different ACPI
hotplug issues
in QEMU 6.1.
As Ani mentioned earlier, QEMU 6.2 is in soft code freeze.
Today(Nov 9) is the date of hard feature freeze.
I suppose this means the fix for the issue with SeaBIOS or the
feature to
cooperate
with the coming change in OVMF won't happen in 6.2?
Patches are allowed if they're bug fixes. If a change requires
coordination
with an OVMF change too though, I think that's going to be difficult to
justify.
Our fallback option is to revert to native hotplug out of the box for
QEMU machine types in 6.2
Nod.
Just make sure we are all on the same page...
It seems that reverting back to PCIe native hotplug for 6.2 is being
discussed
in bug2004829(https://bugzilla.redhat.com/show_bug.cgi?id=2004829).
If these PCIe native patches posted by Gerd Hoffmann in bug 2007129 can
fix the various PCIe hotplug/unplug issues, that will be great!
At least, we have been seeing PCIe virtio-blk/virtio-nic unplugging
issues,
PCIe VFIO hotplugging issue with PCIe native hotplug. Anyway, I'll run
tests
a bit with these patches from my side.
With these patches of improving native hotplug for pcie root ports, the
pcie unplugging issues are gone from my side.
Seems these patches have been upstreamed already. Thank you, Gerd.
Thanks
Annie