Re: [Qemu-devel] [RFC v3 00/15] ARM virt: PCDIMM/NVDIMM at 2TB

[Auger Eric <eric.auger@redhat.com>]

Hi Igor,

On 7/18/18 4:08 PM, Igor Mammedov wrote:
> On Tue,  3 Jul 2018 09:19:43 +0200
> Eric Auger <eric.auger@redhat.com> wrote:
> 
>> This series aims at supporting PCDIMM/NVDIMM intantiation in
>> machvirt at 2TB guest physical address.
>>
>> This is achieved in 3 steps:
>> 1) support more than 40b IPA/GPA
> will it work for TCG as well?
> /important from make check pov and maybe in cases when there is no ARM system available to test/play with the feature/
> 

Sorry I missed this comment.

On A TCG guest ID_AA64MMFR0_EL1.PARange ID register field is the machine
limiting factor as it returns the supported physical address range
(target/arm/cpu64.c):

aarch64_a53_initfn hardcodes PA range to 40bits
	cpu->id_aa64mmfr0 = 0x00001122
aarch64_a57_initfn hardcodes PA Range to 44 bits
    	cpu->id_aa64mmfr0 = 0x00001124

for TCG guests we may add support for the phys-bits option which would
allow to set the PARange instead of hardcoding it.

Thanks

Eric

> 
> 
>> 2) support PCDIMM instantiation
>> 3) support NVDIMM instantiation
>>
>> This series reuses/rebases patches initially submitted by Shameer in [1]
>> and Kwangwoo in [2].
>>
>> I put all parts all together for consistency and due to dependencies
>> however as soon as the kernel dependency is resolved we can consider
>> upstreaming them separately.
>>
>> Support more than 40b IPA/GPA [ patches 1 - 5 ]
>> -----------------------------------------------
>> was "[RFC 0/6] KVM/ARM: Dynamic and larger GPA size"
>>
>> At the moment the guest physical address space is limited to 40b
>> due to KVM limitations. [0] bumps this limitation and allows to
>> create a VM with up to 52b GPA address space.
>>
>> With this series, QEMU creates a virt VM with the max IPA range
>> reported by the host kernel or 40b by default.
>>
>> This choice can be overriden by using the -machine kvm-type=<bits>
>> option with bits within [40, 52]. If <bits> are not supported by
>> the host, the legacy 40b value is used.
>>
>> Currently the EDK2 FW also hardcodes the max number of GPA bits to
>> 40. This will need to be fixed.
>>
>> PCDIMM Support [ patches 6 - 11 ]
>> ---------------------------------
>> was "[RFC 0/5] ARM virt: Support PC-DIMM at 2TB"
>>
>> We instantiate the device_memory at 2TB. Using it obviously requires
>> at least 42b of IPA/GPA. While its max capacity is currently limited
>> to 2TB, the actual size depends on the initial guest RAM size and
>> maxmem parameter.
>>
>> Actual hot-plug and hot-unplug of PC-DIMM is not suported due to lack
>> of support of those features in baremetal.
>>
>> NVDIMM support [ patches 12 - 15 ]
>> ----------------------------------
>>
>> Once the memory hotplug framework is in place it is fairly
>> straightforward to add support for NVDIMM. the machine "nvdimm" option
>> turns the capability on.
>>
>> Best Regards
>>
>> Eric
>>
>> References:
>>
>> [0] [PATCH v3 00/20] arm64: Dynamic & 52bit IPA support
>> https://www.spinics.net/lists/kernel/msg2841735.html
>>
>> [1] [RFC v2 0/6] hw/arm: Add support for non-contiguous iova regions
>> http://patchwork.ozlabs.org/cover/914694/
>>
>> [2] [RFC PATCH 0/3] add nvdimm support on AArch64 virt platform
>> https://lists.gnu.org/archive/html/qemu-devel/2016-07/msg04599.html
>>
>> Tests:
>> - On Cavium Gigabyte, a 48b VM was created.
>> - Migration tests were performed between kernel supporting the
>>   feature and destination kernel not suporting it
>> - test with ACPI: to overcome the limitation of EDK2 FW, virt
>>   memory map was hacked to move the device memory below 1TB.
>>
>> This series can be found at:
>> https://github.com/eauger/qemu/tree/v2.12.0-dimm-2tb-v3
>>
>> History:
>>
>> v2 -> v3:
>> - fix pc_q35 and pc_piix compilation error
>> - kwangwoo's email being not valid anymore, remove his address
>>
>> v1 -> v2:
>> - kvm_get_max_vm_phys_shift moved in arch specific file
>> - addition of NVDIMM part
>> - single series
>> - rebase on David's refactoring
>>
>> v1:
>> - was "[RFC 0/6] KVM/ARM: Dynamic and larger GPA size"
>> - was "[RFC 0/5] ARM virt: Support PC-DIMM at 2TB"
>>
>> Best Regards
>>
>> Eric
>>
>>
>> Eric Auger (9):
>>   linux-headers: header update for KVM/ARM KVM_ARM_GET_MAX_VM_PHYS_SHIFT
>>   hw/boards: Add a MachineState parameter to kvm_type callback
>>   kvm: add kvm_arm_get_max_vm_phys_shift
>>   hw/arm/virt: support kvm_type property
>>   hw/arm/virt: handle max_vm_phys_shift conflicts on migration
>>   hw/arm/virt: Allocate device_memory
>>   acpi: move build_srat_hotpluggable_memory to generic ACPI source
>>   hw/arm/boot: Expose the pmem nodes in the DT
>>   hw/arm/virt: Add nvdimm and nvdimm-persistence options
>>
>> Kwangwoo Lee (2):
>>   nvdimm: use configurable ACPI IO base and size
>>   hw/arm/virt: Add nvdimm hot-plug infrastructure
>>
>> Shameer Kolothum (4):
>>   hw/arm/virt: Add memory hotplug framework
>>   hw/arm/boot: introduce fdt_add_memory_node helper
>>   hw/arm/boot: Expose the PC-DIMM nodes in the DT
>>   hw/arm/virt-acpi-build: Add PC-DIMM in SRAT
>>
>>  accel/kvm/kvm-all.c                            |   2 +-
>>  default-configs/arm-softmmu.mak                |   4 +
>>  hw/acpi/aml-build.c                            |  51 ++++
>>  hw/acpi/nvdimm.c                               |  28 ++-
>>  hw/arm/boot.c                                  | 123 +++++++--
>>  hw/arm/virt-acpi-build.c                       |  10 +
>>  hw/arm/virt.c                                  | 330 ++++++++++++++++++++++---
>>  hw/i386/acpi-build.c                           |  49 ----
>>  hw/i386/pc_piix.c                              |   8 +-
>>  hw/i386/pc_q35.c                               |   8 +-
>>  hw/ppc/mac_newworld.c                          |   2 +-
>>  hw/ppc/mac_oldworld.c                          |   2 +-
>>  hw/ppc/spapr.c                                 |   2 +-
>>  include/hw/acpi/aml-build.h                    |   3 +
>>  include/hw/arm/arm.h                           |   2 +
>>  include/hw/arm/virt.h                          |   7 +
>>  include/hw/boards.h                            |   2 +-
>>  include/hw/mem/nvdimm.h                        |  12 +
>>  include/standard-headers/linux/virtio_config.h |  16 +-
>>  linux-headers/asm-mips/unistd.h                |  18 +-
>>  linux-headers/asm-powerpc/kvm.h                |   1 +
>>  linux-headers/linux/kvm.h                      |  16 ++
>>  target/arm/kvm.c                               |   9 +
>>  target/arm/kvm_arm.h                           |  16 ++
>>  24 files changed, 597 insertions(+), 124 deletions(-)
>>
>