[edk2-devel] [RFC PATCH 0/5] support CPU hot-unplug
Igor Mammedov
imammedo at redhat.com
Mon Dec 21 15:46:39 UTC 2020
On Mon, 21 Dec 2020 15:44:35 +0100
"Laszlo Ersek" <lersek at redhat.com> wrote:
> Hi Ankur,
>
> On 12/08/20 06:34, Ankur Arora wrote:
> > [ Resending to the correct edk2 alias this time. ]
> >
> > Hi,
> >
> > This series adds support for CPU hot-unplug with OVMF.
> >
> > Please see this in conjunction with the QEMU v2 series posted here:
> > https://lore.kernel.org/qemu-devel/20201207140739.3829993-1-imammedo@redhat.com/
> >
> > In particular, would be glad for comments on Patch 4, specifically
> > where we should be ejecting the CPU.
> >
> > Right now the ejection happens in UnplugCpus() (called from
> > CpuHotplugMmi()):
> > + QemuCpuhpWriteCpuSelector (mMmCpuIo, RemoveApicId);
> > + QemuCpuhpWriteCpuStatus (mMmCpuIo, QEMU_CPUHP_STAT_EJECTED);
> >
> > That is way too early -- given that the actual unplug will happen
> > in SmmCpuUpdate() and given that the BSPHandler() would have waited
> > for the APs multiple times before then.
> >
> > Another possibility is that the actual ejection be deferred to the
> > _EJ0 method after the return from the SMI. But, that seems like a
> > hack. Additionally, Igor points out here that this approach has problems:
> > https://lore.kernel.org/qemu-devel/20201204170939.1815522-1-imammedo@redhat.com/
>
> I've filed:
>
> https://bugzilla.tianocore.org/show_bug.cgi?id=3132
>
> Can you please register an account in the TianoCore Bugzilla at
> <https://bugzilla.tianocore.org/>, and assign the above ticket to yourself?
>
> And then, the URL of the new BZ ticket should be included in every
> commit message, like this:
>
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3132
>
> just above your S-o-b.
>
> No need to repost just because of this; I'll review the RFC series later.
BTW:
meanwhile, QEMU part got merged so one doesn't need to hunt for it anymore.
If something is broken there, we will have to fix it on top.
>
> Thanks,
> Laszlo
>
> >
> > Please review.
> >
> > Thanks
> > Ankur
> >
> > Ankur Arora (5):
> > OvmfPkg/CpuHotplugSmm: move CPU Hotplug into PlugCpus()
> > OvmfPkg/CpuHotplugSmm: handle fw_remove
> > OvmfPkg/CpuHotplugSmm: add CpuStatus helper function
> > OvmfPkg/CpuHotplugSmm: handle CPU hot-unplug
> > OvmfPkg/SmmControl2Dxe: negotiate ICH9_LPC_SMI_F_CPU_HOT_UNPLUG
> >
> > OvmfPkg/CpuHotplugSmm/CpuHotplug.c | 293 ++++++++++++------
> > OvmfPkg/CpuHotplugSmm/QemuCpuhp.c | 58 +++-
> > OvmfPkg/CpuHotplugSmm/QemuCpuhp.h | 6 +
> > .../Include/IndustryStandard/QemuCpuHotplug.h | 2 +
> > OvmfPkg/SmmControl2Dxe/SmiFeatures.c | 21 +-
> > 5 files changed, 280 insertions(+), 100 deletions(-)
> >
>
>
>
>
>
>
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#69333): https://edk2.groups.io/g/devel/message/69333
Mute This Topic: https://groups.io/mt/78802720/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-
More information about the edk2-devel-archive
mailing list