RE: [PATCH V4 11/24] xen/mm: Make x86's XENMEM_resource_ioreq_server handling common

[Wei Chen <Wei.Chen@xxxxxxx>]

Hi Oleksandr,

> -----Original Message-----
> From: Xen-devel <xen-devel-bounces@xxxxxxxxxxxxxxxxxxxx> On Behalf Of
> Oleksandr Tyshchenko
> Sent: 2021年1月13日 5:52
> To: xen-devel@xxxxxxxxxxxxxxxxxxxx
> Cc: Julien Grall <Julien.Grall@xxxxxxx>; Jan Beulich <jbeulich@xxxxxxxx>;
> Andrew Cooper <andrew.cooper3@xxxxxxxxxx>; Roger Pau Monné
> <roger.pau@xxxxxxxxxx>; Wei Liu <wl@xxxxxxx>; George Dunlap
> <george.dunlap@xxxxxxxxxx>; Ian Jackson <iwj@xxxxxxxxxxxxxx>; Julien Grall
> <julien@xxxxxxx>; Stefano Stabellini <sstabellini@xxxxxxxxxx>; Volodymyr
> Babchuk <Volodymyr_Babchuk@xxxxxxxx>; Oleksandr Tyshchenko
> <oleksandr_tyshchenko@xxxxxxxx>
> Subject: [PATCH V4 11/24] xen/mm: Make x86's
> XENMEM_resource_ioreq_server handling common
> 
> From: Julien Grall <julien.grall@xxxxxxx>
> 
> As x86 implementation of XENMEM_resource_ioreq_server can be
> re-used on Arm later on, this patch makes it common and removes
> arch_acquire_resource as unneeded.
> 
> Also re-order #include-s alphabetically.
> 
> This support is going to be used on Arm to be able run device
> emulator outside of Xen hypervisor.
> 
> Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
> [On Arm only]
> Tested-by: Wei Chen <Wei.Chen@xxxxxxx>
> 
> ---
> Please note, this is a split/cleanup/hardening of Julien's PoC:
> "Add support for Guest IO forwarding to a device emulator"
> 
> Changes RFC -> V1:
>    - no changes
> 
> Changes V1 -> V2:
>    - update the author of a patch
> 
> Changes V2 -> V3:
>    - don't wrap #include <xen/ioreq.h>
>    - limit the number of #ifdef-s
>    - re-order #include-s alphabetically
> 
> Changes V3 -> V4:
>    - rebase
>    - Add Jan's R-b
> ---
>  xen/arch/x86/mm.c        | 44 ---------------------------------
>  xen/common/memory.c      | 63
> +++++++++++++++++++++++++++++++++++++++---------
>  xen/include/asm-arm/mm.h |  8 ------
>  xen/include/asm-x86/mm.h |  4 ---
>  4 files changed, 51 insertions(+), 68 deletions(-)
> 
> diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
> index f6e128e..54ac398 100644
> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -4587,50 +4587,6 @@ static int handle_iomem_range(unsigned long s,
> unsigned long e, void *p)
>      return err || s > e ? err : _handle_iomem_range(s, e, p);
>  }
> 
> -int arch_acquire_resource(struct domain *d, unsigned int type,
> -                          unsigned int id, unsigned long frame,
> -                          unsigned int nr_frames, xen_pfn_t mfn_list[])
> -{
> -    int rc;
> -
> -    switch ( type )
> -    {
> -#ifdef CONFIG_HVM
> -    case XENMEM_resource_ioreq_server:
> -    {
> -        ioservid_t ioservid = id;
> -        unsigned int i;
> -
> -        rc = -EINVAL;
> -        if ( !is_hvm_domain(d) )
> -            break;
> -
> -        if ( id != (unsigned int)ioservid )
> -            break;
> -
> -        rc = 0;
> -        for ( i = 0; i < nr_frames; i++ )
> -        {
> -            mfn_t mfn;
> -
> -            rc = hvm_get_ioreq_server_frame(d, id, frame + i, &mfn);
> -            if ( rc )
> -                break;
> -
> -            mfn_list[i] = mfn_x(mfn);
> -        }
> -        break;
> -    }
> -#endif
> -
> -    default:
> -        rc = -EOPNOTSUPP;
> -        break;
> -    }
> -
> -    return rc;
> -}
> -
>  long arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void)
> arg)
>  {
>      int rc;
> diff --git a/xen/common/memory.c b/xen/common/memory.c
> index b21b6c4..7e560b5 100644
> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -8,22 +8,23 @@
>   */
> 
>  #include <xen/domain_page.h>
> -#include <xen/types.h>
> +#include <xen/errno.h>
> +#include <xen/event.h>
> +#include <xen/grant_table.h>
> +#include <xen/guest_access.h>
> +#include <xen/hypercall.h>
> +#include <xen/iocap.h>
> +#include <xen/ioreq.h>
>  #include <xen/lib.h>
> +#include <xen/mem_access.h>
>  #include <xen/mm.h>
> +#include <xen/numa.h>
> +#include <xen/paging.h>
>  #include <xen/param.h>
>  #include <xen/perfc.h>
>  #include <xen/sched.h>
> -#include <xen/event.h>
> -#include <xen/paging.h>
> -#include <xen/iocap.h>
> -#include <xen/guest_access.h>
> -#include <xen/hypercall.h>
> -#include <xen/errno.h>
> -#include <xen/numa.h>
> -#include <xen/mem_access.h>
>  #include <xen/trace.h>
> -#include <xen/grant_table.h>
> +#include <xen/types.h>
>  #include <asm/current.h>
>  #include <asm/hardirq.h>
>  #include <asm/p2m.h>
> @@ -1090,6 +1091,40 @@ static int acquire_grant_table(struct domain *d,
> unsigned int id,
>      return 0;
>  }
> 
> +static int acquire_ioreq_server(struct domain *d,
> +                                unsigned int id,
> +                                unsigned long frame,
> +                                unsigned int nr_frames,
> +                                xen_pfn_t mfn_list[])
> +{
> +#ifdef CONFIG_IOREQ_SERVER
> +    ioservid_t ioservid = id;
> +    unsigned int i;
> +    int rc;
> +
> +    if ( !is_hvm_domain(d) )
> +        return -EINVAL;
> +
> +    if ( id != (unsigned int)ioservid )
> +        return -EINVAL;
> +
> +    for ( i = 0; i < nr_frames; i++ )
> +    {
> +        mfn_t mfn;
> +
> +        rc = hvm_get_ioreq_server_frame(d, id, frame + i, &mfn);
> +        if ( rc )
> +            return rc;
> +
> +        mfn_list[i] = mfn_x(mfn);
> +    }
> +
> +    return 0;
> +#else
> +    return -EOPNOTSUPP;
> +#endif
> +}
> +
>  static int acquire_resource(
>      XEN_GUEST_HANDLE_PARAM(xen_mem_acquire_resource_t) arg)
>  {
> @@ -1148,9 +1183,13 @@ static int acquire_resource(
>                                   mfn_list);
>          break;
> 
> +    case XENMEM_resource_ioreq_server:
> +        rc = acquire_ioreq_server(d, xmar.id, xmar.frame, xmar.nr_frames,
> +                                  mfn_list);
> +        break;
> +
>      default:
> -        rc = arch_acquire_resource(d, xmar.type, xmar.id, xmar.frame,
> -                                   xmar.nr_frames, mfn_list);
> +        rc = -EOPNOTSUPP;
>          break;
>      }
> 
> diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
> index f8ba49b..0b7de31 100644
> --- a/xen/include/asm-arm/mm.h
> +++ b/xen/include/asm-arm/mm.h
> @@ -358,14 +358,6 @@ static inline void put_page_and_type(struct page_info
> *page)
> 
>  void clear_and_clean_page(struct page_info *page);
> 
> -static inline
> -int arch_acquire_resource(struct domain *d, unsigned int type, unsigned int 
> id,
> -                          unsigned long frame, unsigned int nr_frames,
> -                          xen_pfn_t mfn_list[])
> -{
> -    return -EOPNOTSUPP;
> -}
> -
>  unsigned int arch_get_dma_bitsize(void);
> 

This change could not be applied to the latest staging branch.

>  #endif /*  __ARCH_ARM_MM__ */
> diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h
> index deeba75..859214e 100644
> --- a/xen/include/asm-x86/mm.h
> +++ b/xen/include/asm-x86/mm.h
> @@ -639,8 +639,4 @@ static inline bool arch_mfn_in_directmap(unsigned long
> mfn)
>      return mfn <= (virt_to_mfn(eva - 1) + 1);
>  }
> 
> -int arch_acquire_resource(struct domain *d, unsigned int type,
> -                          unsigned int id, unsigned long frame,
> -                          unsigned int nr_frames, xen_pfn_t mfn_list[]);
> -
>  #endif /* __ASM_X86_MM_H__ */
> --
> 2.7.4
>