From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH v5 RFC 09/14] tools/libxc: x86 PV restore
 code
Date: Thu, 12 Jun 2014 18:01:29 +0100
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To: David Vrabel <david.vrabel@citrix.com>
Cc: Frediano Ziglio <frediano.ziglio@citrix.com>, Xen-devel <xen-devel@lists.xen.org>
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On 12/06/14 16:49, David Vrabel wrote:
> On 11/06/14 19:14, Andrew Cooper wrote:
>> --- /dev/null
>> +++ b/tools/libxc/saverestore/restore_x86_pv.c
> ...
>> +static int x86_pv_process_record(struct context *ctx, struct record *rec)
>> +{
>> +    xc_interface *xch = ctx->xch;
>> +
>> +    switch ( rec->type )
>> +    {
>> +    case REC_TYPE_X86_PV_INFO:
>> +        return handle_x86_pv_info(ctx, rec);
>> +
> ...
>> +
>> +    case REC_TYPE_X86_PV_VCPU_MSRS:
>> +        return handle_x86_pv_vcpu_msrs(ctx, rec);
>> +
>> +    default:
>> +        if ( rec->type & REC_TYPE_OPTIONAL )
>> +        {
>> +            IPRINTF("Ignoring optional record (0x%"PRIx32", %s)",
>> +                    rec->type, rec_type_to_str(rec->type));
>> +            return 0;
>> +        }
>> +
>> +        ERROR("Invalid record type (0x%"PRIx32", %s) for x86_pv domains",
>> +              rec->type, rec_type_to_str(rec->type));
>> +        return -1;
>> +    }
> I think this default case can be moved to common code.  Perhaps return
> XC_SR_RECORD_UNHANDLED (== 1) to indicate the record wasn't handled.
>
> David

It am looking to not adversely affect any attempt to standardise libxc
error reporting in the future, which is why all this code uses 0 or -1,
even though errno might or might not be relevant.  Even at the moment,
there are callbacks into higher level toolstacks which can return any
arbitrary error.

~Andrew