Re: [Xen-devel] [PATCH v3 23/24] libxl: Add support for non-PCI passthrough

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Tue, 13 Jan 2015, Julien Grall wrote:
> On ARM, every non-PCI device are described in the device tree. Each of them
> can be found via a path.
> 
> This patch introduces a very basic support, only the IOMMU will be set
> up correctly. The user will have to:
>     - Describe the device in the partial device tree
>     - Map manually MMIO/IRQ
> 
> This is a first approach, that will allow to have a basic non-PCI
> passthrough support in Xen. This could be improved later.
> 
> Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
> Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
> Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
> 
> ---
>     Changes in v3:
>         - Dynamic allocation has been dropped
>         - Rework the commit message in accordance with the previous
>         item
> 
>     Changes in v2:
>         - Get DT infos earlier
>         - Allocate/map IRQ in libxl__arch_domain_create rather than in
>         libxl__device_dt_add
>         - Use VIRQ rather than the PIRQ to construct the interrupts
>         properties of the device tree
>         - Correct cpumask in make_dtdev_node. We allow the interrupt to
>         be used on the 8 CPUs
>         - Fix LOGE when we map the MMIO region in the guest in
>         libxl__device_dt_add. The domain and the IRQ were inverted
>         - Calculate the number of SPIs to configure the VGIC
>         - xc_physdev_dtdev_* helpers has been renamed to xc_dtdev_*
>         - Rename libxl_device_dt to libxl_device_dtdev
> ---
>  tools/libxl/Makefile         |  2 +-
>  tools/libxl/libxl_create.c   | 10 ++++++++++
>  tools/libxl/libxl_dtdev.c    | 34 ++++++++++++++++++++++++++++++++++
>  tools/libxl/libxl_internal.h |  5 +++++
>  tools/libxl/libxl_types.idl  |  5 +++++
>  5 files changed, 55 insertions(+), 1 deletion(-)
>  create mode 100644 tools/libxl/libxl_dtdev.c
> 
> diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
> index b417372..98e1bab 100644
> --- a/tools/libxl/Makefile
> +++ b/tools/libxl/Makefile
> @@ -96,7 +96,7 @@ LIBXL_OBJS = flexarray.o libxl.o libxl_create.o libxl_dm.o 
> libxl_pci.o \
>                       libxl_json.o libxl_aoutils.o libxl_numa.o \
>                       libxl_save_callout.o _libxl_save_msgs_callout.o \
>                       libxl_qmp.o libxl_event.o libxl_fork.o $(LIBXL_OBJS-y)
> -LIBXL_OBJS += libxl_genid.o
> +LIBXL_OBJS += libxl_genid.o libxl_dtdev.o
>  LIBXL_OBJS += _libxl_types.o libxl_flask.o _libxl_types_internal.o
>  
>  LIBXL_TESTS += timedereg
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index 029d2e2..b7ef528 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -1430,6 +1430,16 @@ static void domcreate_attach_pci(libxl__egc *egc, 
> libxl__multidev *multidev,

I think you should at least rename domcreate_attach_pci to something
more generic, like domcreate_attach_dev.


>          }
>      }
>  
> +    for (i = 0; i < d_config->num_dtdevs; i++) {
> +
> +        ret = libxl__device_dt_add(gc, domid, &d_config->dtdevs[i]);
> +        if (ret < 0) {
> +            LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
> +                       "libxl__device_dt_add failed: %d\n", ret);
> +            goto error_out;
> +        }
> +    }

You are allowed to call xc_* functions from here. The
libxl__device_dt_add wrapper doesn't add much value.


>      domcreate_console_available(egc, dcs);
>  
>      domcreate_complete(egc, dcs, 0);
> diff --git a/tools/libxl/libxl_dtdev.c b/tools/libxl/libxl_dtdev.c
> new file mode 100644
> index 0000000..5de57f0
> --- /dev/null
> +++ b/tools/libxl/libxl_dtdev.c
> @@ -0,0 +1,34 @@
> +/*
> + * Copyright (C) 2014      Linaro Limited.
> + * Author Julien Grall <julien.grall@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU Lesser General Public License as published
> + * by the Free Software Foundation; version 2.1 only. with the special
> + * exception on linking described in file LICENSE.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU Lesser General Public License for more details.
> + */
> +
> +#include "libxl_osdeps.h" /* Must come before other headers */
> +
> +#include "libxl_internal.h"
> +
> +int libxl__device_dt_add(libxl__gc *gc, uint32_t domid,
> +                         const libxl_device_dtdev *dtdev)
> +{
> +    LOG(DEBUG, "Assign device \"%s\" to dom%u", dtdev->path, domid);
> +
> +    return xc_assign_dt_device(CTX->xch, domid, dtdev->path);
> +}
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-basic-offset: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
> index be5ed82..c00516a 100644
> --- a/tools/libxl/libxl_internal.h
> +++ b/tools/libxl/libxl_internal.h
> @@ -1179,6 +1179,11 @@ _hidden int libxl__create_pci_backend(libxl__gc *gc, 
> uint32_t domid,
>                                        libxl_device_pci *pcidev, int num);
>  _hidden int libxl__device_pci_destroy_all(libxl__gc *gc, uint32_t domid);
>  
> +/* from libxl_dtdev */
> +
> +_hidden int libxl__device_dt_add(libxl__gc *gc, uint32_t domid,
> +                                 const libxl_device_dtdev *dtdev);
> +
>  /*----- xswait: wait for a xenstore node to be suitable -----*/
>  
>  typedef struct libxl__xswait_state libxl__xswait_state;
> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
> index 5651110..c10fd2f 100644
> --- a/tools/libxl/libxl_types.idl
> +++ b/tools/libxl/libxl_types.idl
> @@ -522,6 +522,10 @@ libxl_device_pci = Struct("device_pci", [
>      ("seize", bool),
>      ])
>  
> +libxl_device_dtdev = Struct("device_dtdev", [
> +    ("path", string),
> +    ])
> +
>  libxl_device_vtpm = Struct("device_vtpm", [
>      ("backend_domid",    libxl_domid),
>      ("backend_domname",  string),
> @@ -548,6 +552,7 @@ libxl_domain_config = Struct("domain_config", [
>      ("disks", Array(libxl_device_disk, "num_disks")),
>      ("nics", Array(libxl_device_nic, "num_nics")),
>      ("pcidevs", Array(libxl_device_pci, "num_pcidevs")),
> +    ("dtdevs", Array(libxl_device_dtdev, "num_dtdevs")),
>      ("vfbs", Array(libxl_device_vfb, "num_vfbs")),
>      ("vkbs", Array(libxl_device_vkb, "num_vkbs")),
>      ("vtpms", Array(libxl_device_vtpm, "num_vtpms")),
> -- 
> 2.1.4
> 

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