Re: [Qemu-arm] [RFC PATCH 0/4] ARM virt: ACPI memory hotplug support

[Shameerali Kolothum Thodi]

Hi Eric,

> -----Original Message-----
> From: Auger Eric [mailto:address@hidden
> Sent: 22 February 2019 16:03
> To: Shameerali Kolothum Thodi <address@hidden>;
> address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden
> Cc: xuwei (O) <address@hidden>; Linuxarm <address@hidden>; Ard
> Biesheuvel <address@hidden>; Leif Lindholm (Linaro address)
> <address@hidden>; Laszlo Ersek <address@hidden>
> Subject: Re: [RFC PATCH 0/4] ARM virt: ACPI memory hotplug support
> 
> Hi Shameer,
> 
> On 1/28/19 12:05 PM, Shameer Kolothum wrote:
> > This series is an attempt to provide hotplug support to both
> > pc-dimm and nvdimm device memory on ARM virt platform. This is
> > based on Eric's recent works to support PCDIMM/NVDIMM device
> memory[1].
> > The kernel support for arm64 memory hot add was added only
> > recently by Robin[2] and hence the guest kernel should be => 5.0-rc1.
> >
> > This makes use of PL061 GPIO controller to sent related ACPI events
> s/sent/send
> > to the Guest. The only reference I could find with respect to the GPIO
> > pins usage is here[3] which says, "use PIN 3 for system_powerdown,
> > reserving PIN 0, 1, 2 for PCI hotplug, CPU hotplug and memory hotplug".
> > Hence Pin 2 is used for PCDIMM and pin 4 for NVDIMM.
> >
> > This is sanity tested on a HiSilicon ARM64 platform and appreciate
> > any further testing.
> 
> I did some testing on another platform and I got the exactly the same
> results as yours: PCDIMM hot plug works fine. Also after system_reset I
> still can see the slots.
> Hot-unplug is not supported though.

Thanks for giving it a spin. Hot unplug is disabled for now as kernel doesn’t
have support for it yet.

> For NVDIMM, hot-add works fine and and I can see the slots using ndctl
> on guest. But after system_reset, the guest does not boot properly.

Right. And I assume you are seeing the same error message as below.
Thanks for adding relevant people to the discussion.

Cheers,
Shameer

> >
> > This series can be applied on top of Eric's branch here[4]
> >
> > Test:
> > ------
> > Please use a Guest kernel image >5.0-rc1 with all the mem/nvdimm
> > hotplug related CONFIGs enabled.
> >
> > ./qemu-system-aarch64 \
> > -machine virt,gic-version=3,nvdimm \
> > -m 1G,maxmem=4G,slots=4 \
> > -cpu host \
> > -kernel Image \
> > -initrd rootfs-iperf.cpio \
> > -bios QEMU_EFI.fd \
> > -numa node,nodeid=0 \
> > -net none \
> > -nographic -enable-kvm \
> > -append "console=ttyAMA0 acpi=force earlycon=pl011,0x9000000"
> >
> > Enter Qemu monitor,
> > Add pc-dimm:
> > object_add memory-backend-ram,id=mem1,size=1G
> > device_add pc-dimm,id=dimm1,memdev=mem1
> >
> > Add nvdimm:
> > object_add memory-backend-ram,id=mem2,size=1G
> > device_add nvdimm,id=dimm2,memdev=mem2
> >
> > Known Issue:
> >
> > It is observed that hot adding nvdimm will results in guest reboot
> > failure. EDK2 fails to build the ACPI tables on reboot. Please find
> > below EDK2 log on Guest reboot after nvdimm hot-add,
> >
> > ProcessCmdAddChecksum: invalid checksum range in "etc/acpi/tables"
> > OnRootBridgesConnected: InstallAcpiTables: Protocol Error
> >
> > The root cause seems to be EDK2 ACPI table checksum failure
> > as NFIT table is getting updated on hot-add. This needs further
> > investigation.
> + Ard, Leif, Laszlo if they have any idea of what is missing/wrong.
> 
> Thanks
> 
> Eric
> >
> > Thanks,
> > Shameer
> >
> > [1]https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg05740.html
> > [2]https://patchwork.kernel.org/patch/10724455/
> > [3]https://lists.gnu.org/archive/html/qemu-arm/2015-12/msg00095.html
> > [4]https://github.com/eauger/qemu/tree/v3.1.0-dimm-v5
> >
> > Shameer Kolothum (4):
> >   hw:acpi: Make ACPI IO address space configurable
> >   hw/arm/virt: Add GPIO based pcdimm hotplug ACPI event support
> >   hw/arm/virt: Enable pc-dimm hotplug support
> >   hw/arm/virt: Add nvdimm hotplug support
> >
> >  default-configs/arm-softmmu.mak  |   1 +
> >  hw/acpi/memory_hotplug.c         |  13 +++--
> >  hw/arm/virt-acpi-build.c         |  45 +++++++++++++++--
> >  hw/arm/virt.c                    | 105
> ++++++++++++++++++++++++++++++++++++---
> >  hw/i386/acpi-build.c             |   3 +-
> >  include/hw/acpi/memory_hotplug.h |   6 ++-
> >  include/hw/arm/virt.h            |  15 ++++++
> >  7 files changed, 168 insertions(+), 20 deletions(-)
> >