Re: [RFC v1 2/5] xen/arm: add generic SCI mediator framework

[Oleksii Moisieiev <Oleksii_Moisieiev@xxxxxxxx>]

Hi Stefano,

On Thu, Dec 16, 2021 at 06:45:11PM -0800, Stefano Stabellini wrote:
> On Tue, 14 Dec 2021, Oleksii Moisieiev wrote:
> > This patch adds the basic framework for SCI mediator.
> > SCI is System Control Interface, which is designed to redirect
> > requests for the Hardware (such as power-domain/clock/resets etc)
> > from the Domains to the firmware. Originally, cpg should be passed
> > to the domain so it can work with power-domains/clocks/resets etc.
> > Considering that cpg can't be split between the Domains, we get the
> > limitation that the devices, which are using power-domains/clocks/resets
> > etc, couldn't be split between the domains.
> > The solution is to move the power-domain/clock/resets etc to the
> > Firmware (such as SCP firmware or ATF) and provide interface for the 
> > Domains.
> > XEN shoud have an entity, caled SCI-Mediator, which is responsible for 
> > messages
> > redirection between Domains and Firmware and for permission handling.
> > 
> > This is how it works: user can build XEN with multiple SCI mediators.
> > See the next patches, where SCMI-SMC mediator is introduced.
> > SCI mediator register itself with REGISTER_SCI_MEDIATOR() macro.
> > 
> > At run-time, during initialization, framework calls probe for the first
> > matching device in the device-tree. When no device-tree is present - the
> > first registered mediator should be probed.
> > 
> > Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> > ---
> >  MAINTAINERS                    |   6 ++
> >  xen/arch/arm/Kconfig           |   8 ++
> >  xen/arch/arm/Makefile          |   1 +
> >  xen/arch/arm/domain.c          |  24 +++++
> >  xen/arch/arm/domain_build.c    |  11 +++
> >  xen/arch/arm/platforms/rcar3.c |   3 +-
> >  xen/arch/arm/sci/Makefile      |   1 +
> >  xen/arch/arm/sci/sci.c         | 128 ++++++++++++++++++++++++++
> >  xen/arch/arm/setup.c           |   1 +
> >  xen/arch/arm/xen.lds.S         |   7 ++
> >  xen/include/asm-arm/domain.h   |   4 +
> >  xen/include/asm-arm/sci/sci.h  | 162 +++++++++++++++++++++++++++++++++
> >  xen/include/public/arch-arm.h  |  10 ++
> >  13 files changed, 365 insertions(+), 1 deletion(-)
> >  create mode 100644 xen/arch/arm/sci/Makefile
> >  create mode 100644 xen/arch/arm/sci/sci.c
> >  create mode 100644 xen/include/asm-arm/sci/sci.h
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index e43dc0edce..5f96ea35ba 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -512,6 +512,12 @@ S:     Supported
> >  F: xen/arch/arm/tee/
> >  F: xen/include/asm-arm/tee
> >  
> > +SCI MEDIATORS
> > +M: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> > +S: Supported
> > +F: xen/arch/arm/sci
> > +F: xen/include/asm-arm/sci
> > +
> >  TOOLSTACK
> >  M: Wei Liu <wl@xxxxxxx>
> >  S: Supported
> > diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
> > index ecfa6822e4..186e1db389 100644
> > --- a/xen/arch/arm/Kconfig
> > +++ b/xen/arch/arm/Kconfig
> > @@ -106,6 +106,14 @@ config TEE
> >  
> >  source "arch/arm/tee/Kconfig"
> >  
> > +config SCI
> > +   bool "Enable SCI mediators support"
> > +   default n
> > +   help
> > +     This option enables generic SCI (System Control Interface) mediators
> > +     support. It allows guests to control system resourcess via one of
> > +     SCI mediators implemented in XEN.
> > +
> >  endmenu
> >  
> >  menu "ARM errata workaround via the alternative framework"
> > diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> > index 07f634508e..6366ff55e5 100644
> > --- a/xen/arch/arm/Makefile
> > +++ b/xen/arch/arm/Makefile
> > @@ -8,6 +8,7 @@ obj-y += platforms/
> >  endif
> >  obj-$(CONFIG_TEE) += tee/
> >  obj-$(CONFIG_HAS_VPCI) += vpci.o
> > +obj-$(CONFIG_SCI) += sci/
> >  
> >  obj-$(CONFIG_HAS_ALTERNATIVE) += alternative.o
> >  obj-y += bootfdt.init.o
> > diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
> > index 96e1b23550..80d0a23767 100644
> > --- a/xen/arch/arm/domain.c
> > +++ b/xen/arch/arm/domain.c
> > @@ -34,6 +34,7 @@
> >  #include <asm/platform.h>
> >  #include <asm/procinfo.h>
> >  #include <asm/regs.h>
> > +#include <asm/sci/sci.h>
> >  #include <asm/tee/tee.h>
> >  #include <asm/vfp.h>
> >  #include <asm/vgic.h>
> > @@ -688,6 +689,13 @@ int arch_sanitise_domain_config(struct 
> > xen_domctl_createdomain *config)
> >          return -EINVAL;
> >      }
> >  
> > +    if ( config->arch.sci_type != XEN_DOMCTL_CONFIG_SCI_NONE &&
> > +         config->arch.sci_type != sci_get_type() )
> > +    {
> > +        dprintk(XENLOG_INFO, "Unsupported SCI type\n");
> > +        return -EINVAL;
> > +    }
> > +
> >      return 0;
> >  }
> >  
> > @@ -764,6 +772,15 @@ int arch_domain_create(struct domain *d,
> >          /* At this stage vgic_reserve_virq should never fail */
> >          if ( !vgic_reserve_virq(d, GUEST_EVTCHN_PPI) )
> >              BUG();
> > +
> > +        if ( config->arch.sci_type != XEN_DOMCTL_CONFIG_SCI_NONE )
> > +        {
> > +            if ( (rc = sci_domain_init(d, config->arch.sci_type)) != 0)
> > +                goto fail;
> > +
> > +            if ( (rc = sci_get_channel_info(d, &config->arch)) != 0)
> > +                goto fail;
> > +        }
> >      }
> >  
> >      /*
> > @@ -796,6 +813,7 @@ void arch_domain_destroy(struct domain *d)
> >      domain_vgic_free(d);
> >      domain_vuart_free(d);
> >      free_xenheap_page(d->shared_info);
> > +    sci_domain_destroy(d);
> >  #ifdef CONFIG_ACPI
> >      free_xenheap_pages(d->arch.efi_acpi_table,
> >                         get_order_from_bytes(d->arch.efi_acpi_len));
> > @@ -996,6 +1014,7 @@ enum {
> >      PROG_xen,
> >      PROG_page,
> >      PROG_mapping,
> > +    PROG_sci,
> >      PROG_done,
> >  };
> >  
> > @@ -1056,6 +1075,11 @@ int domain_relinquish_resources(struct domain *d)
> >          if ( ret )
> >              return ret;
> >  
> > +    PROGRESS(sci):
> > +        ret = sci_relinquish_resources(d);
> > +        if ( ret )
> > +            return ret;
> > +
> >      PROGRESS(done):
> >          break;
> >  
> > diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> > index d02bacbcd1..38874615dd 100644
> > --- a/xen/arch/arm/domain_build.c
> > +++ b/xen/arch/arm/domain_build.c
> > @@ -22,6 +22,7 @@
> >  #include <asm/kernel.h>
> >  #include <asm/setup.h>
> >  #include <asm/tee/tee.h>
> > +#include <asm/sci/sci.h>
> >  #include <asm/platform.h>
> >  #include <asm/psci.h>
> >  #include <asm/setup.h>
> > @@ -1894,6 +1895,10 @@ static int __init handle_device(struct domain *d, 
> > struct dt_device_node *dev,
> >                  return res;
> >              }
> >          }
> > +
> > +        res = sci_add_dt_device(d, dev);
> > +        if ( res < 0 )
> > +            return res;
> >      }
> 
> It would be good to add the call to dom0less domUs too
> 

Thank you, I will fix all mentioned places in v2.

> 
> >      res = handle_device_interrupts(d, dev, need_mapping);
> > @@ -3075,6 +3080,10 @@ static int __init construct_dom0(struct domain *d)
> >      if ( rc < 0 )
> >          return rc;
> >  
> > +    rc = sci_domain_init(d, sci_get_type());
> > +    if ( rc < 0 )
> > +        return rc;
> 
> same here
> 

TBD in v2

> 
> >      if ( acpi_disabled )
> >          rc = prepare_dtb_hwdom(d, &kinfo);
> >      else
> > @@ -3109,6 +3118,8 @@ void __init create_dom0(void)
> >      dom0_cfg.arch.tee_type = tee_get_type();
> >      dom0_cfg.max_vcpus = dom0_max_vcpus();
> >  
> > +    dom0_cfg.arch.sci_type = sci_get_type();
> 
> and here
> 
TBD in v2
> 
> >      if ( iommu_enabled )
> >          dom0_cfg.flags |= XEN_DOMCTL_CDF_iommu;
> >  
> > diff --git a/xen/arch/arm/platforms/rcar3.c b/xen/arch/arm/platforms/rcar3.c
> > index d740145c71..a268b09454 100644
> > --- a/xen/arch/arm/platforms/rcar3.c
> > +++ b/xen/arch/arm/platforms/rcar3.c
> > @@ -18,10 +18,11 @@
> >   */
> >  
> >  #include <asm/platform.h>
> > +#include <asm/sci/sci.h>
> >  
> >  static bool rcar3_smc(struct cpu_user_regs *regs)
> >  {
> > -    return false;
> > +    return sci_handle_call(current->domain, regs);
> >  }
> >  
> >  static const char *const rcar3_dt_compat[] __initconst =
> > diff --git a/xen/arch/arm/sci/Makefile b/xen/arch/arm/sci/Makefile
> > new file mode 100644
> > index 0000000000..837dc7492b
> > --- /dev/null
> > +++ b/xen/arch/arm/sci/Makefile
> > @@ -0,0 +1 @@
> > +obj-y += sci.o
> > diff --git a/xen/arch/arm/sci/sci.c b/xen/arch/arm/sci/sci.c
> > new file mode 100644
> > index 0000000000..5961b4cd5d
> > --- /dev/null
> > +++ b/xen/arch/arm/sci/sci.c
> > @@ -0,0 +1,128 @@
> > +/*
> > + * xen/arch/arm/sci/sci.c
> > + *
> > + * Generic part of SCI mediator driver
> > + *
> > + * Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> > + * Copyright (C) 2021, EPAM Systems.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License as published by
> > + * the Free Software Foundation; either version 2 of the License, or
> > + * (at your option) any later version.
> > + *
> > + * 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 General Public License for more details.
> > + */
> > +
> > +#include <xen/errno.h>
> > +#include <xen/init.h>
> > +#include <xen/sched.h>
> > +#include <xen/types.h>
> > +
> > +#include <asm/sci/sci.h>
> > +
> > +extern const struct sci_mediator_desc _sscimediator[], _escimediator[];
> > +static const struct sci_mediator_desc __read_mostly *cur_mediator;
> > +
> > +bool sci_handle_call(struct domain *d, void *args)
> > +{
> > +    if ( unlikely(!cur_mediator) )
> > +        return false;
> > +
> > +    return cur_mediator->ops->handle_call(d, args);
> > +}
> > +
> > +int sci_domain_init(struct domain *d, uint16_t sci_type)
> > +{
> > +    if ( sci_type == XEN_DOMCTL_CONFIG_SCI_NONE )
> > +        return 0;
> > +
> > +    if ( unlikely(!cur_mediator) )
> > +        return -ENODEV;
> > +
> > +    if ( cur_mediator->sci_type != sci_type )
> > +        return -EINVAL;
> > +
> > +    return cur_mediator->ops->domain_init(d);
> > +}
> > +
> > +void sci_domain_destroy(struct domain *d)
> > +{
> > +    if ( unlikely(!cur_mediator) )
> > +        return;
> > +
> > +    cur_mediator->ops->domain_destroy(d);
> > +}
> > +
> > +int sci_relinquish_resources(struct domain *d)
> > +{
> > +    if ( unlikely(!cur_mediator) )
> > +        return 0;
> > +
> > +    return cur_mediator->ops->relinquish_resources(d);
> > +}
> > +
> > +
> > +int sci_add_dt_device(struct domain *d, struct dt_device_node *dev)
> > +{
> > +    if ( unlikely(!cur_mediator) )
> > +        return 0;
> > +
> > +    return cur_mediator->ops->add_dt_device(d, dev);
> > +}
> > +
> > +int sci_get_channel_info(struct domain *d,
> > +                         struct xen_arch_domainconfig *config)
> > +{
> > +    if ( unlikely(!cur_mediator) )
> > +        return 0;
> > +
> > +    return cur_mediator->ops->get_channel_info(d->arch.sci, config);
> > +}
> > +
> > +uint16_t sci_get_type(void)
> > +{
> > +    if ( unlikely(!cur_mediator) )
> > +        return XEN_DOMCTL_CONFIG_SCI_NONE;
> > +
> > +    return cur_mediator->sci_type;
> > +}
> > +
> > +static int __init sci_init(void)
> > +{
> > +    const struct sci_mediator_desc *desc;
> > +    struct dt_device_node *dt = NULL;
> > +
> > +    for ( desc = _sscimediator; desc != _escimediator; desc++ )
> > +    {
> > +        if ( likely(dt_host) )
> 
> I think you can assume that dt_host is correctly set, right?
> Instead of this check, I would just add:
> 
>     if ( !acpi_disabled )
>         return -ENODEV;
> 
> at the beginning of sci_init
> 

Good point! I will it in v2. Thanks.

> 
> > +        {
> > +            dt = dt_find_matching_node(dt_host, desc->dt_match);
> > +            if ( !dt )
> > +                continue;
> > +        }
> > +
> > +        if ( desc->ops->probe(dt) )
> > +        {
> > +            printk(XENLOG_INFO "Using SCI mediator for %s\n", desc->name);
> > +            cur_mediator = desc;
> > +            return 0;
> > +        }
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> > +__initcall(sci_init);
> > +
> > +/*
> > + * Local variables:
> > + * mode: C
> > + * c-file-style: "BSD"
> > + * c-basic-offset: 4
> > + * indent-tabs-mode: nil
> > + * End:
> > + */
> > diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> > index d5d0792ed4..201de01411 100644
> > --- a/xen/arch/arm/setup.c
> > +++ b/xen/arch/arm/setup.c
> > @@ -50,6 +50,7 @@
> >  #include <asm/cpufeature.h>
> >  #include <asm/platform.h>
> >  #include <asm/procinfo.h>
> > +#include <asm/sci/sci.h>
> >  #include <asm/setup.h>
> >  #include <xsm/xsm.h>
> >  #include <asm/acpi.h>
> > diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
> > index 08016948ab..3683f4821f 100644
> > --- a/xen/arch/arm/xen.lds.S
> > +++ b/xen/arch/arm/xen.lds.S
> > @@ -142,6 +142,13 @@ SECTIONS
> >        _eteemediator = .;
> >    } :text
> >  
> > +  . = ALIGN(8);
> > +  .scimediator.info : {
> > +      _sscimediator = .;
> > +      *(.scimediator.info)
> > +      _escimediator = .;
> > +  } :text
> > +
> >    . = ALIGN(PAGE_SIZE);             /* Init code and data */
> >    __init_begin = .;
> >    .init.text : {
> > diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
> > index 9b3647587a..d9b164017f 100644
> > --- a/xen/include/asm-arm/domain.h
> > +++ b/xen/include/asm-arm/domain.h
> > @@ -89,6 +89,10 @@ struct arch_domain
> >  #ifdef CONFIG_TEE
> >      void *tee;
> >  #endif
> > +
> > +#ifdef CONFIG_SCI
> > +    void *sci;
> > +#endif
> >  }  __cacheline_aligned;
> >  
> >  struct arch_vcpu
> > diff --git a/xen/include/asm-arm/sci/sci.h b/xen/include/asm-arm/sci/sci.h
> > new file mode 100644
> > index 0000000000..aeff689c72
> > --- /dev/null
> > +++ b/xen/include/asm-arm/sci/sci.h
> > @@ -0,0 +1,162 @@
> > +/*
> > + * xen/include/asm-arm/sci/sci.h
> > + *
> > + * Generic part of the SCI (System Control Interface) subsystem.
> > + *
> > + * Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> > + * Copyright (C) 2021, EPAM Systems.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License as published by
> > + * the Free Software Foundation; either version 2 of the License, or
> > + * (at your option) any later version.
> > + *
> > + * 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 General Public License for more details.
> > + */
> > +
> > +#ifndef __ASM_ARM_SCI_H
> > +#define __ASM_ARM_SCI_H
> > +
> > +#include <xen/lib.h>
> > +#include <xen/types.h>
> > +#include <xen/device_tree.h>
> > +
> > +#ifdef CONFIG_SCI
> > +
> > +struct sci_mediator_ops {
> > +
> > +    /*
> > +     * Probe for SCI. Should return true if SCI found and
> > +     * mediator is initialized.
> > +     */
> > +    bool (*probe)(struct dt_device_node *scmi_node);
> > +
> > +    /*
> > +     * Called during domain construction if toolstack requests to enable
> > +     * SCI support so mediator can inform SCP-firmware about new
> > +     * guest and create own structures for the new domain.
> > +     */
> > +    int (*domain_init)(struct domain *d);
> > +
> > +    /*
> > +     * Called during domain destruction, releases all resources, that
> > +     * were allocated by the mediator.
> > +     */
> > +    void (*domain_destroy)(struct domain *d);
> > +
> > +    /*
> > +     * Called during parsing partial device-sci for the domain.
> > +     * Passing device_node so mediator could process the device and
> > +     * mark the device as related to the domain if needed.
> > +     */
> > +    int (*add_dt_device)(struct domain *d, struct dt_device_node *dev);
> > +
> > +    /*
> > +     * Called during domain destruction to relinquish resources used
> > +     * by mediator itself. This function can return -ERESTART to indicate
> > +     * that it does not finished work and should be called again.
> > +     */
> > +    int (*relinquish_resources)(struct domain *d);
> > +
> > +    /* Handle call for current domain */
> > +    bool (*handle_call)(struct domain *d, void *regs);
> > +
> > +    /* Gets channel configuration and store it in domainconfig */
> > +    int (*get_channel_info)(void *sci_ops,
> > +                            struct xen_arch_domainconfig *config);
> 
> get_channel_info is the only function I don't understand among these...
> what is supposed to be stored in struct xen_arch_domainconfig, just
> sci_agent_paddr?
> 
> Also, it seems to be only called right after sci_domain_init, so can't
> the "get_channel_info" operation just be done as part of domain_init?
> 

We need sci_agent_paddr for Domains. It represents shmem address which
should be mapped to guest Domain. We also don't need paddr when we do
sci_domain_init for dom0. That's why I've made it as separate call.

Also I named it get_channel_info, not get_channel_paddr, because
potentially, the different information can be needed from different SCI
implementation, which doesn't need shared memory to pass data for
exapmle.

> 
> 
> > +};
> > +
> > +struct sci_mediator_desc {
> > +    /* Printable name of the SCI. */
> > +    const char *name;
> > +
> > +    /* Mediator callbacks as described above. */
> > +    const struct sci_mediator_ops *ops;
> > +
> > +    /*
> > +     * ID of SCI. Corresponds to xen_arch_domainconfig.sci_type.
> > +     * Should be one of XEN_DOMCTL_CONFIG_SCI_xxx
> > +     */
> > +    uint16_t sci_type;
> > +
> > +    /* Match structure to init mediator */
> > +    const struct dt_device_match *dt_match;
> > +
> > +};
> > +
> > +int sci_domain_init(struct domain *d, uint16_t sci_type);
> > +void sci_domain_destroy(struct domain *d);
> > +int sci_add_dt_device(struct domain *d, struct dt_device_node *dev);
> > +int sci_relinquish_resources(struct domain *d);
> > +bool sci_handle_call(struct domain *d, void *args);
> > +int sci_get_channel_info(struct domain *d,
> > +                         struct xen_arch_domainconfig *config);
> > +uint16_t sci_get_type(void);
> > +
> > +#define REGISTER_SCI_MEDIATOR(_name, _namestr, _type, _match, _ops) \
> > +static const struct sci_mediator_desc __sci_desc_##_name __used     \
> > +__section(".scimediator.info") = {                                  \
> > +    .name = _namestr,                                               \
> > +    .ops = _ops,                                                    \
> > +    .sci_type = _type,                                              \
> > +    .dt_match = _match                                              \
> > +}
> > +
> > +#else
> > +#include <public/errno.h>
> > +
> > +static inline int sci_domain_init(struct domain *d, uint16_t sci_type)
> > +{
> > +    if ( likely(sci_type == XEN_DOMCTL_CONFIG_SCI_NONE) )
> > +        return 0;
> > +
> > +    return -XEN_ENODEV;
> > +}
> > +
> > +static inline void sci_domain_destroy(struct domain *d)
> > +{
> > +}
> > +
> > +static inline int sci_add_dt_device(struct domain *d,
> > +                                    struct dt_device_node *dev)
> > +{
> > +    return 0;
> > +}
> > +
> > +static inline int sci_relinquish_resources(struct domain *d)
> > +{
> > +    return 0;
> > +}
> > +
> > +static inline bool sci_handle_call(struct domain *d, void *args)
> > +{
> > +    return false;
> > +}
> > +
> > +static inline int sci_get_channel_info(struct domain *d,
> > +                                       struct xen_arch_domainconfig 
> > *config)
> > +{
> > +    return 0;
> > +}
> > +
> > +static inline uint16_t sci_get_type(void)
> > +{
> > +    return XEN_DOMCTL_CONFIG_SCI_NONE;
> > +}
> > +
> > +#endif  /* CONFIG_SCI */
> > +
> > +#endif /* __ASM_ARM_SCI_H */
> > +
> > +/*
> > + * Local variables:
> > + * mode: C
> > + * c-file-style: "BSD"
> > + * c-basic-offset: 4
> > + * indent-tabs-mode: nil
> > + * End:
> > + */
> > diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
> > index 94b31511dd..9180be5e86 100644
> > --- a/xen/include/public/arch-arm.h
> > +++ b/xen/include/public/arch-arm.h
> > @@ -314,12 +314,16 @@ DEFINE_XEN_GUEST_HANDLE(vcpu_guest_context_t);
> >  #define XEN_DOMCTL_CONFIG_TEE_NONE      0
> >  #define XEN_DOMCTL_CONFIG_TEE_OPTEE     1
> >  
> > +#define XEN_DOMCTL_CONFIG_SCI_NONE      0
> > +
> >  struct xen_arch_domainconfig {
> >      /* IN/OUT */
> >      uint8_t gic_version;
> >      /* IN */
> >      uint16_t tee_type;
> >      /* IN */
> > +    uint8_t sci_type;
> 
> sci_type is uint16_t everywhere else
> 
> 
> > +    /* IN */
> >      uint32_t nr_spis;
> >      /*
> >       * OUT
> > @@ -335,6 +339,12 @@ struct xen_arch_domainconfig {
> >       *
> >       */
> >      uint32_t clock_frequency;
> > +
> > +    /* Sets shared address to sw domains.
> > +     * This information is needed to set correct channel in Domain partial
> > +     * device-tree
> > +     */
> > +    uint64_t sci_agent_paddr;
> >  };
> >  #endif /* __XEN__ || __XEN_TOOLS__ */
>