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

[Auger Eric]

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.
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.

> 
> 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(-)
>