Re: [PATCH v2] libxc: try to find last used pfn when migrating

[Juergen Gross <jgross@suse.com>]

On 02/12/15 16:28, Ian Campbell wrote:
> On Wed, 2015-12-02 at 12:36 +0000, Andrew Cooper wrote:
>> On 02/12/15 07:42, Juergen Gross wrote:
>>> diff --git a/tools/libxc/xc_sr_save_x86_hvm.c
>>> b/tools/libxc/xc_sr_save_x86_hvm.c
>>> index cdee774..3c879ed 100644
>>> --- a/tools/libxc/xc_sr_save_x86_hvm.c
>>> +++ b/tools/libxc/xc_sr_save_x86_hvm.c
>>> @@ -135,6 +135,20 @@ static int x86_hvm_normalise_page(struct
>>> xc_sr_context *ctx,
>>>  static int x86_hvm_setup(struct xc_sr_context *ctx)
>>>  {
>>>      xc_interface *xch = ctx->xch;
>>> +    xen_pfn_t nr_pfns;
>>> +
>>> +    if ( xc_domain_nr_gpfns(xch, ctx->domid, &nr_pfns) < 0 )
>>> +    {
>>> +        PERROR("Unable to obtain the guest p2m size");
>>> +        return -1;
>>> +    }
>>> +    if ( nr_pfns > ~XEN_DOMCTL_PFINFO_LTAB_MASK )
>>> +    {
>>> +        PERROR("Cannot save this big a guest");
>>
>> Strictly speaking to match the moved code, this should set errno = E2BIG.
>>
>> However, the error handling in libxc is in a dire state, and the error
>> message is retained, which is the important point.
>>
>> Entire patch Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> with
>> or without the errno tweaks.
> 
> I could make the errno tweak on commit, if there is agreement.

Sure, go ahead.


Juergen