Re: [PATCH V2 00/23] IOREQ feature (+ virtio-mmio) on Arm

[Masami Hiramatsu <masami.hiramatsu@linaro.org>]

Hi Oleksandr,

I would like to try this on my arm64 board.

According to your comments in the patch, I made this config file.
# cat debian.conf
name = "debian"
type = "pvh"
vcpus = 8
memory = 512
kernel = "/opt/agl/vmlinuz-5.9.0-1-arm64"
ramdisk = "/opt/agl/initrd.img-5.9.0-1-arm64"
cmdline= "console=hvc0 earlyprintk=xen root=/dev/xvda1 rw"
disk = [ '/opt/agl/debian.qcow2,qcow2,hda' ]
vif = [ 'mac=00:16:3E:74:3d:76,bridge=xenbr0' ]
virtio = 1
vdisk = [ 'backend=Dom0, disks=ro:/dev/sda1' ]

And tried to boot a DomU, but I got below error.

# xl create -c debian.conf
Parsing config from debian.conf
libxl: error: libxl_create.c:1863:domcreate_attach_devices: Domain
1:unable to add virtio_disk devices
libxl: error: libxl_domain.c:1218:destroy_domid_pci_done: Domain
1:xc_domain_pause failed
libxl: error: libxl_dom.c:39:libxl__domain_type: unable to get domain
type for domid=1
libxl: error: libxl_domain.c:1136:domain_destroy_callback: Domain
1:Unable to destroy guest
libxl: error: libxl_domain.c:1063:domain_destroy_cb: Domain
1:Destruction of domain failed


Could you tell me how can I test it?

Thank you,

2020年10月16日(金) 1:46 Oleksandr Tyshchenko <olekstysh@gmail.com>:
>
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>
> Hello all.
>
> The purpose of this patch series is to add IOREQ/DM support to Xen on Arm.
> You can find an initial discussion at [1] and RFC/V1 series at [2]/[3].
> Xen on Arm requires some implementation to forward guest MMIO access to a device
> model in order to implement virtio-mmio backend or even mediator outside of hypervisor.
> As Xen on x86 already contains required support this series tries to make it common
> and introduce Arm specific bits plus some new functionality. Patch series is based on
> Julien's PoC "xen/arm: Add support for Guest IO forwarding to a device emulator".
> Besides splitting existing IOREQ/DM support and introducing Arm side, the series
> also includes virtio-mmio related changes (last 2 patches for toolstack)
> for the reviewers to be able to see how the whole picture could look like.
>
> According to the initial discussion there are a few open questions/concerns
> regarding security, performance in VirtIO solution:
> 1. virtio-mmio vs virtio-pci, SPI vs MSI, different use-cases require different
>    transport...
> 2. virtio backend is able to access all guest memory, some kind of protection
>    is needed: 'virtio-iommu in Xen' vs 'pre-shared-memory & memcpys in guest'
> 3. interface between toolstack and 'out-of-qemu' virtio backend, avoid using
>    Xenstore in virtio backend if possible.
> 4. a lot of 'foreing mapping' could lead to the memory exhaustion, Julien
>    has some idea regarding that.
>
> Looks like all of them are valid and worth considering, but the first thing
> which we need on Arm is a mechanism to forward guest IO to a device emulator,
> so let's focus on it in the first place.
>
> ***
>
> There are a lot of changes since RFC series, almost all TODOs were resolved on Arm,
> Arm code was improved and hardened, common IOREQ/DM code became really arch-agnostic
> (without HVM-ism), but one TODO still remains which is "PIO handling" on Arm.
> The "PIO handling" TODO is expected to left unaddressed for the current series.
> It is not an big issue for now while Xen doesn't have support for vPCI on Arm.
> On Arm64 they are only used for PCI IO Bar and we would probably want to expose
> them to emulator as PIO access to make a DM completely arch-agnostic. So "PIO handling"
> should be implemented when we add support for vPCI.
>
> I left interface untouched in the following patch
> "xen/dm: Introduce xendevicemodel_set_irq_level DM op"
> since there is still an open discussion what interface to use/what
> information to pass to the hypervisor.
>
> Also I decided to drop the following patch:
> "[RFC PATCH V1 07/12] A collection of tweaks to be able to run emulator in driver domain"
> as I got an advise to write our own policy using FLASK which would cover our use
> case (with emulator in driver domain) rather than tweak Xen.
>
> There are two patches on review this series depends on (each involved patch in this series
> contains this note as well):
> 1. https://patchwork.kernel.org/patch/11816689
> 2. https://patchwork.kernel.org/patch/11803383
>
> Please note, that IOREQ feature is disabled by default within this series.
>
> ***
>
> Patch series [4] was rebased on recent "staging branch"
> (8a62dee x86/vLAPIC: don't leak regs page from vlapic_init() upon error) and tested on
> Renesas Salvator-X board + H3 ES3.0 SoC (Arm64) with virtio-mmio disk backend (we will
> share it later) running in driver domain and unmodified Linux Guest running on existing
> virtio-blk driver (frontend). No issues were observed. Guest domain 'reboot/destroy'
> use-cases work properly. Patch series was only build-tested on x86.
>
> Please note, build-test passed for the following modes:
> 1. x86: CONFIG_HVM=y / CONFIG_IOREQ_SERVER=y (default)
> 2. x86: #CONFIG_HVM is not set / #CONFIG_IOREQ_SERVER is not set
> 3. Arm64: CONFIG_HVM=y / CONFIG_IOREQ_SERVER=y
> 4. Arm64: CONFIG_HVM=y / #CONFIG_IOREQ_SERVER is not set  (default)
> 5. Arm32: CONFIG_HVM=y / CONFIG_IOREQ_SERVER=y
> 6. Arm32: CONFIG_HVM=y / #CONFIG_IOREQ_SERVER is not set  (default)
>
> ***
>
> Any feedback/help would be highly appreciated.
>
> [1] https://lists.xenproject.org/archives/html/xen-devel/2020-07/msg00825.html
> [2] https://lists.xenproject.org/archives/html/xen-devel/2020-08/msg00071.html
> [3] https://lists.xenproject.org/archives/html/xen-devel/2020-09/msg00732.html
> [4] https://github.com/otyshchenko1/xen/commits/ioreq_4.14_ml3
>
> Julien Grall (5):
>   xen/dm: Make x86's DM feature common
>   xen/mm: Make x86's XENMEM_resource_ioreq_server handling common
>   arm/ioreq: Introduce arch specific bits for IOREQ/DM features
>   xen/dm: Introduce xendevicemodel_set_irq_level DM op
>   libxl: Introduce basic virtio-mmio support on Arm
>
> Oleksandr Tyshchenko (18):
>   x86/ioreq: Prepare IOREQ feature for making it common
>   xen/ioreq: Make x86's IOREQ feature common
>   xen/ioreq: Make x86's hvm_ioreq_needs_completion() common
>   xen/ioreq: Provide alias for the handle_mmio()
>   xen/ioreq: Make x86's hvm_mmio_first(last)_byte() common
>   xen/ioreq: Make x86's hvm_ioreq_(page/vcpu/server) structs common
>   xen/ioreq: Move x86's ioreq_gfn(server) to struct domain
>   xen/ioreq: Introduce ioreq_params to abstract accesses to
>     arch.hvm.params
>   xen/ioreq: Move x86's io_completion/io_req fields to struct vcpu
>   xen/ioreq: Remove "hvm" prefixes from involved function names
>   xen/ioreq: Use guest_cmpxchg64() instead of cmpxchg()
>   xen/arm: Stick around in leave_hypervisor_to_guest until I/O has
>     completed
>   xen/mm: Handle properly reference in set_foreign_p2m_entry() on Arm
>   xen/ioreq: Introduce domain_has_ioreq_server()
>   xen/arm: io: Abstract sign-extension
>   xen/ioreq: Make x86's send_invalidate_req() common
>   xen/arm: Add mapcache invalidation handling
>   [RFC] libxl: Add support for virtio-disk configuration
>
>  MAINTAINERS                                     |    8 +-
>  tools/libs/devicemodel/core.c                   |   18 +
>  tools/libs/devicemodel/include/xendevicemodel.h |    4 +
>  tools/libs/devicemodel/libxendevicemodel.map    |    1 +
>  tools/libs/light/Makefile                       |    1 +
>  tools/libs/light/libxl_arm.c                    |   94 +-
>  tools/libs/light/libxl_create.c                 |    1 +
>  tools/libs/light/libxl_internal.h               |    1 +
>  tools/libs/light/libxl_types.idl                |   16 +
>  tools/libs/light/libxl_types_internal.idl       |    1 +
>  tools/libs/light/libxl_virtio_disk.c            |  109 ++
>  tools/xl/Makefile                               |    2 +-
>  tools/xl/xl.h                                   |    3 +
>  tools/xl/xl_cmdtable.c                          |   15 +
>  tools/xl/xl_parse.c                             |  116 ++
>  tools/xl/xl_virtio_disk.c                       |   46 +
>  xen/arch/arm/Makefile                           |    2 +
>  xen/arch/arm/dm.c                               |   89 ++
>  xen/arch/arm/domain.c                           |    9 +
>  xen/arch/arm/hvm.c                              |    4 +
>  xen/arch/arm/io.c                               |   29 +-
>  xen/arch/arm/ioreq.c                            |  126 ++
>  xen/arch/arm/p2m.c                              |   29 +
>  xen/arch/arm/traps.c                            |   58 +-
>  xen/arch/x86/Kconfig                            |    1 +
>  xen/arch/x86/hvm/Makefile                       |    1 -
>  xen/arch/x86/hvm/dm.c                           |  291 +----
>  xen/arch/x86/hvm/emulate.c                      |   60 +-
>  xen/arch/x86/hvm/hvm.c                          |   24 +-
>  xen/arch/x86/hvm/hypercall.c                    |    9 +-
>  xen/arch/x86/hvm/intercept.c                    |    5 +-
>  xen/arch/x86/hvm/io.c                           |   26 +-
>  xen/arch/x86/hvm/ioreq.c                        | 1533 -----------------------
>  xen/arch/x86/hvm/stdvga.c                       |   10 +-
>  xen/arch/x86/hvm/svm/nestedsvm.c                |    2 +-
>  xen/arch/x86/hvm/vmx/realmode.c                 |    6 +-
>  xen/arch/x86/hvm/vmx/vvmx.c                     |    2 +-
>  xen/arch/x86/mm.c                               |   46 +-
>  xen/arch/x86/mm/p2m.c                           |   13 +-
>  xen/arch/x86/mm/shadow/common.c                 |    2 +-
>  xen/common/Kconfig                              |    3 +
>  xen/common/Makefile                             |    2 +
>  xen/common/dm.c                                 |  292 +++++
>  xen/common/ioreq.c                              | 1443 +++++++++++++++++++++
>  xen/common/memory.c                             |   50 +-
>  xen/include/asm-arm/domain.h                    |    5 +
>  xen/include/asm-arm/hvm/ioreq.h                 |  109 ++
>  xen/include/asm-arm/mm.h                        |    8 -
>  xen/include/asm-arm/mmio.h                      |    1 +
>  xen/include/asm-arm/p2m.h                       |   19 +-
>  xen/include/asm-arm/paging.h                    |    4 +
>  xen/include/asm-arm/traps.h                     |   24 +
>  xen/include/asm-x86/hvm/domain.h                |   50 +-
>  xen/include/asm-x86/hvm/emulate.h               |    2 +-
>  xen/include/asm-x86/hvm/io.h                    |   17 -
>  xen/include/asm-x86/hvm/ioreq.h                 |  198 ++-
>  xen/include/asm-x86/hvm/vcpu.h                  |   18 -
>  xen/include/asm-x86/mm.h                        |    4 -
>  xen/include/asm-x86/p2m.h                       |   20 +-
>  xen/include/public/arch-arm.h                   |    5 +
>  xen/include/public/hvm/dm_op.h                  |   16 +
>  xen/include/xen/dm.h                            |   44 +
>  xen/include/xen/ioreq.h                         |  143 +++
>  xen/include/xen/p2m-common.h                    |    4 +
>  xen/include/xen/sched.h                         |   37 +
>  xen/include/xsm/dummy.h                         |    4 +-
>  xen/include/xsm/xsm.h                           |    6 +-
>  xen/xsm/dummy.c                                 |    2 +-
>  xen/xsm/flask/hooks.c                           |    5 +-
>  69 files changed, 3223 insertions(+), 2125 deletions(-)
>  create mode 100644 tools/libs/light/libxl_virtio_disk.c
>  create mode 100644 tools/xl/xl_virtio_disk.c
>  create mode 100644 xen/arch/arm/dm.c
>  create mode 100644 xen/arch/arm/ioreq.c
>  delete mode 100644 xen/arch/x86/hvm/ioreq.c
>  create mode 100644 xen/common/dm.c
>  create mode 100644 xen/common/ioreq.c
>  create mode 100644 xen/include/asm-arm/hvm/ioreq.h
>  create mode 100644 xen/include/xen/dm.h
>  create mode 100644 xen/include/xen/ioreq.h
>
> --
> 2.7.4
>
>


-- 
Masami Hiramatsu