Re: [PATCH 11/13] xen: XEN_DOMCTL_shadow_op hypercall

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 29/11/13 11:25, Ian Campbell wrote:
> On Thu, 2013-11-28 at 18:56 +0000, Andrew Cooper wrote:
>> And some of the sub-subops.  It is a little hacky given the legacy way of
>> having several methods of enabling/disbling LOG_DIRTY mode.
> Does the hypervisor still support all those methods. For valgrind
> purposes we only care as far back as 4.1 I think?

Sadly yes, and xc_domain_save() I believe makes use of both of them. 
(Most of these patches are from 6 months ago, so I don't remember for
certain)

While it is not explicitly deprecated in the ABI, it is still fair game
to use either method.

~Andrew

>
> Regardless, I intend to send this patch upstream.
>
>> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
>> ---
>>  coregrind/m_syswrap/syswrap-xen.c |   64 +++++++++++++++++++++++++++++++++++++
>>  include/vki/vki-xen-domctl.h      |   36 ++++++++++++++++++++-
>>  2 files changed, 99 insertions(+), 1 deletion(-)
>>
>> diff --git a/coregrind/m_syswrap/syswrap-xen.c b/coregrind/m_syswrap/syswrap-xen.c
>> index ea4a7c0..056f2b8 100644
>> --- a/coregrind/m_syswrap/syswrap-xen.c
>> +++ b/coregrind/m_syswrap/syswrap-xen.c
>> @@ -696,6 +696,49 @@ PRE(domctl)
>>        __PRE_XEN_DOMCTL_READ(getvcpuextstate, vcpuextstate, buffer);
>>        break;
>>  
>> +   case VKI_XEN_DOMCTL_shadow_op:
>> +       PRE_XEN_DOMCTL_READ(shadow_op, op);
>> +
>> +       switch(domctl->u.shadow_op.op)
>> +       {
>> +       case VKI_XEN_DOMCTL_SHADOW_OP_OFF:
>> +           /* No further inputs */
>> +           break;
>> +
>> +       case VKI_XEN_DOMCTL_SHADOW_OP_ENABLE:
>> +           PRE_XEN_DOMCTL_READ(shadow_op, mode);
>> +           switch(domctl->u.shadow_op.mode)
>> +           {
>> +           case XEN_DOMCTL_SHADOW_ENABLE_LOG_DIRTY:
>> +               goto domctl_shadow_op_enable_logdirty;
>> +
>> +
>> +           default:
>> +               bad_subop(tid, layout, arrghs, status, flags,
>> +                         "__HYPERVISOR_domctl shadowop mode",
>> +                         domctl->u.shadow_op.mode);
>> +               break;
>> +           }
>> +
>> +       case VKI_XEN_DOMCTL_SHADOW_OP_ENABLE_LOGDIRTY:
>> +       domctl_shadow_op_enable_logdirty:
>> +           /* No further inputs */
>> +           break;
>> +
>> +       case VKI_XEN_DOMCTL_SHADOW_OP_CLEAN:
>> +       case VKI_XEN_DOMCTL_SHADOW_OP_PEEK:
>> +           PRE_XEN_DOMCTL_READ(shadow_op, dirty_bitmap);
>> +           PRE_XEN_DOMCTL_READ(shadow_op, pages);
>> +           break;
>> +
>> +       default:
>> +           bad_subop(tid, layout, arrghs, status, flags,
>> +                     "__HYPERVISOR_domctl shadow(10)",
>> +                     domctl->u.shadow_op.op);
>> +           break;
>> +       }
>> +       break;
>> +
>>     default:
>>        bad_subop(tid, layout, arrghs, status, flags,
>>                  "__HYPERVISOR_domctl", domctl->cmd);
>> @@ -1212,6 +1255,27 @@ POST(domctl){
>>                       domctl->u.vcpuextstate.size);
>>        break;
>>  
>> +   case VKI_XEN_DOMCTL_shadow_op:
>> +       switch(domctl->u.shadow_op.op)
>> +       {
>> +       case VKI_XEN_DOMCTL_SHADOW_OP_OFF:
>> +           /* No outputs */
>> +           break;
>> +
>> +       case VKI_XEN_DOMCTL_SHADOW_OP_CLEAN:
>> +       case VKI_XEN_DOMCTL_SHADOW_OP_PEEK:
>> +           POST_XEN_DOMCTL_WRITE(shadow_op, pages);
>> +           POST_XEN_DOMCTL_WRITE(shadow_op, stats.fault_count);
>> +           POST_XEN_DOMCTL_WRITE(shadow_op, stats.dirty_count);
>> +           if(domctl->u.shadow_op.dirty_bitmap.p)
>> +               POST_MEM_WRITE((Addr)domctl->u.shadow_op.dirty_bitmap.p,
>> +                              domctl->u.shadow_op.pages * sizeof(vki_uint8_t));
>> +           break;
>> +
>> +       default:
>> +           break;
>> +       }
>> +       break;
>>     }
>>  #undef POST_XEN_DOMCTL_WRITE
>>  #undef __POST_XEN_DOMCTL_WRITE
>> diff --git a/include/vki/vki-xen-domctl.h b/include/vki/vki-xen-domctl.h
>> index 67dc2ef..7cce4af 100644
>> --- a/include/vki/vki-xen-domctl.h
>> +++ b/include/vki/vki-xen-domctl.h
>> @@ -173,6 +173,40 @@ struct vki_xen_domctl_vcpuaffinity {
>>      struct vki_xenctl_bitmap cpumap; /* IN/OUT */
>>  };
>>  
>> +struct vki_xen_domctl_shadow_op_stats {
>> +    vki_uint32_t fault_count;
>> +    vki_uint32_t dirty_count;
>> +};
>> +
>> +/* vki_xen_domctl_shadow_op.op is an utter mess for compatibily reasons. */
>> +
>> +struct vki_xen_domctl_shadow_op {
>> +    vki_uint32_t op; /* IN */
>> +
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_OFF               0
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_ENABLE           32
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_CLEAN            11
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_PEEK             12
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_GET_ALLOCATION   30
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_SET_ALLOCATION   31
>> +
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_ENABLE_TEST       1
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_ENABLE_LOGDIRTY   2
>> +#define VKI_XEN_DOMCTL_SHADOW_OP_ENABLE_TRANSLATE  3
>> +
>> +    vki_uint32_t mode;
>> +
>> +#define XEN_DOMCTL_SHADOW_ENABLE_REFCOUNT  (1 << 1)
>> +#define XEN_DOMCTL_SHADOW_ENABLE_LOG_DIRTY (1 << 2)
>> +#define XEN_DOMCTL_SHADOW_ENABLE_TRANSLATE (1 << 3)
>> +#define XEN_DOMCTL_SHADOW_ENABLE_EXTERNAL  (1 << 4)
>> +
>> +    vki_uint32_t mb;
>> +    VKI_XEN_GUEST_HANDLE_64(vki_uint8) dirty_bitmap;
>> +    vki_xen_uint64_aligned_t pages;
>> +    struct vki_xen_domctl_shadow_op_stats stats;
>> +};
>> +
>>  struct vki_xen_domctl_max_mem {
>>      /* IN variables. */
>>      vki_xen_uint64_aligned_t max_memkb;
>> @@ -285,7 +319,7 @@ struct vki_xen_domctl {
>>          struct vki_xen_domctl_getpageframeinfo3 getpageframeinfo3;
>>          struct vki_xen_domctl_nodeaffinity      nodeaffinity;
>>          struct vki_xen_domctl_vcpuaffinity      vcpuaffinity;
>> -        //struct vki_xen_domctl_shadow_op         shadow_op;
>> +        struct vki_xen_domctl_shadow_op         shadow_op;
>>          struct vki_xen_domctl_max_mem           max_mem;
>>          struct vki_xen_domctl_vcpucontext       vcpucontext;
>>          struct vki_xen_domctl_getvcpuinfo       getvcpuinfo;
>