Re: [PATCH 0/5] ARM hypercall ABI: 64 bit ready

[David Vrabel <david.vrabel@citrix.com>]

On 06/08/12 15:11, Stefano Stabellini wrote:
> Hi all,
> this patch series makes the necessary changes to make sure that the
> current ARM hypercall ABI can be used as-is on 64 bit ARM platforms:
> 
> - it defines xen_ulong_t as uint64_t on ARM;
> - it introduces a new macro to handle guest pointers, called
> XEN_GUEST_HANDLE_PARAM (that has size 4 bytes on aarch and is going to
> have size 8 bytes on aarch64);
> - it replaces all the occurrences of XEN_GUEST_HANDLE in hypercall
> parameters with XEN_GUEST_HANDLE_PARAM.

This is a subtle (and undocumented!) distinction. I can see people
adding/modifying hypercall etc. getting this wrong and no one noticing
for a while (since it doesn't affect x86).

The xen_ulong_t parameters (when used for pointers) from an aarch guest
point of view are a uint32_t guest pointer and uint32_t of padding.  So
the guest handles will be the same size in hypercall parameters and
structure members.

David

> On x86 and ia64 things should stay exactly the same.
> 
> On ARM all the unsigned long and the guest pointers that are members of
> a struct become size 8 byte (both aarch and aarch64).
> However guest pointers that are passed as hypercall arguments in
> registers are going to be 4 bytes on aarch and 8 bytes on aarch64.
> 
> It is based on Ian's arm-for-4.3 branch. 
> 
> 
> Stefano Stabellini (5):
>       xen: improve changes to xen_add_to_physmap
>       xen/arm: introduce __lshrdi3 and __aeabi_llsr
>       xen: few more xen_ulong_t substitutions
>       xen: introduce XEN_GUEST_HANDLE_PARAM
>       xen: replace XEN_GUEST_HANDLE with XEN_GUEST_HANDLE_PARAM when appropriate
> 
> 
>  xen/arch/arm/domain.c              |    2 +-
>  xen/arch/arm/domctl.c              |    2 +-
>  xen/arch/arm/hvm.c                 |    2 +-
>  xen/arch/arm/lib/Makefile          |    2 +-
>  xen/arch/arm/lib/lshrdi3.S         |   54 ++++++++++++++++++++++++++++++++++++
>  xen/arch/arm/mm.c                  |    2 +-
>  xen/arch/arm/physdev.c             |    2 +-
>  xen/arch/arm/sysctl.c              |    2 +-
>  xen/arch/x86/cpu/mcheck/mce.c      |    2 +-
>  xen/arch/x86/domain.c              |    2 +-
>  xen/arch/x86/domctl.c              |    2 +-
>  xen/arch/x86/efi/runtime.c         |    2 +-
>  xen/arch/x86/hvm/hvm.c             |   26 ++++++++--------
>  xen/arch/x86/microcode.c           |    2 +-
>  xen/arch/x86/mm.c                  |   14 ++++----
>  xen/arch/x86/mm/hap/hap.c          |    2 +-
>  xen/arch/x86/mm/mem_event.c        |    2 +-
>  xen/arch/x86/mm/paging.c           |    2 +-
>  xen/arch/x86/mm/shadow/common.c    |    2 +-
>  xen/arch/x86/physdev.c             |    2 +-
>  xen/arch/x86/platform_hypercall.c  |    2 +-
>  xen/arch/x86/sysctl.c              |    2 +-
>  xen/arch/x86/traps.c               |    2 +-
>  xen/arch/x86/x86_32/mm.c           |    2 +-
>  xen/arch/x86/x86_32/traps.c        |    2 +-
>  xen/arch/x86/x86_64/compat/mm.c    |    8 ++--
>  xen/arch/x86/x86_64/domain.c       |    2 +-
>  xen/arch/x86/x86_64/mm.c           |    2 +-
>  xen/arch/x86/x86_64/traps.c        |    2 +-
>  xen/common/compat/domain.c         |    2 +-
>  xen/common/compat/grant_table.c    |    2 +-
>  xen/common/compat/memory.c         |    2 +-
>  xen/common/domain.c                |    2 +-
>  xen/common/domctl.c                |    2 +-
>  xen/common/event_channel.c         |    2 +-
>  xen/common/grant_table.c           |   36 ++++++++++++------------
>  xen/common/kernel.c                |    4 +-
>  xen/common/kexec.c                 |   16 +++++-----
>  xen/common/memory.c                |    4 +-
>  xen/common/multicall.c             |    2 +-
>  xen/common/schedule.c              |    2 +-
>  xen/common/sysctl.c                |    2 +-
>  xen/common/xenoprof.c              |    8 ++--
>  xen/drivers/acpi/pmstat.c          |    2 +-
>  xen/drivers/char/console.c         |    6 ++--
>  xen/drivers/passthrough/iommu.c    |    2 +-
>  xen/include/asm-arm/guest_access.h |    2 +-
>  xen/include/asm-arm/hypercall.h    |    2 +-
>  xen/include/asm-arm/mm.h           |    2 +-
>  xen/include/asm-x86/hap.h          |    2 +-
>  xen/include/asm-x86/hypercall.h    |   24 ++++++++--------
>  xen/include/asm-x86/mem_event.h    |    2 +-
>  xen/include/asm-x86/mm.h           |    8 ++--
>  xen/include/asm-x86/paging.h       |    2 +-
>  xen/include/asm-x86/processor.h    |    2 +-
>  xen/include/asm-x86/shadow.h       |    2 +-
>  xen/include/asm-x86/xenoprof.h     |    6 ++--
>  xen/include/public/arch-arm.h      |   21 ++++++++++----
>  xen/include/public/arch-ia64.h     |    1 +
>  xen/include/public/arch-x86/xen.h  |    1 +
>  xen/include/public/memory.h        |   11 ++++--
>  xen/include/public/physdev.h       |    2 +-
>  xen/include/public/version.h       |    2 +-
>  xen/include/public/xen.h           |    4 +-
>  xen/include/xen/acpi.h             |    4 +-
>  xen/include/xen/hypercall.h        |   52 +++++++++++++++++-----------------
>  xen/include/xen/iommu.h            |    2 +-
>  xen/include/xen/tmem_xen.h         |    2 +-
>  xen/include/xsm/xsm.h              |    4 +-
>  xen/xsm/dummy.c                    |    2 +-
>  xen/xsm/flask/flask_op.c           |    4 +-
>  xen/xsm/flask/hooks.c              |    2 +-
>  xen/xsm/xsm_core.c                 |    2 +-
>  73 files changed, 243 insertions(+), 175 deletions(-)
> 
> 
> Cheers,
> 
> Stefano
> 
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