From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52023) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WS8PM-00067E-1g for qemu-devel@nongnu.org; Mon, 24 Mar 2014 13:11:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WS8PC-0001I6-Nn for qemu-devel@nongnu.org; Mon, 24 Mar 2014 13:11:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11934) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WS8PC-0001Hz-F4 for qemu-devel@nongnu.org; Mon, 24 Mar 2014 13:11:22 -0400 Date: Mon, 24 Mar 2014 17:11:16 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20140324171115.GI3829@work-vm> References: <1395671853-2685-1-git-send-email-mst@redhat.com> <1395671853-2685-4-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1395671853-2685-4-git-send-email-mst@redhat.com> Subject: Re: [Qemu-devel] [RFC v2 3/5] vmstate: add VMS_MUST_EXIST List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Peter Maydell , qemu-devel@nongnu.org * Michael S. Tsirkin (mst@redhat.com) wrote: > Can be used to verify a required field exists or validate > state in some other way. > > Signed-off-by: Michael S. Tsirkin > --- > include/migration/vmstate.h | 1 + > vmstate.c | 10 +++++++++- > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h > index 3a1587e..eb90cef 100644 > --- a/include/migration/vmstate.h > +++ b/include/migration/vmstate.h > @@ -101,6 +101,7 @@ enum VMStateFlags { > VMS_MULTIPLY = 0x200, /* multiply "size" field by field_size */ > VMS_VARRAY_UINT8 = 0x400, /* Array with size in uint8_t field*/ > VMS_VARRAY_UINT32 = 0x800, /* Array with size in uint32_t field*/ > + VMS_MUST_EXIST = 0x1000, /* Field must exist in input */ > }; > > typedef struct { > diff --git a/vmstate.c b/vmstate.c > index fe53735..4943b83 100644 > --- a/vmstate.c > +++ b/vmstate.c > @@ -13,7 +13,7 @@ static int vmstate_n_elems(void *opaque, VMStateField *field) > { > int n_elems = 1; > > - if (!(field->flags & ~VMS_NONE)) { > + if (!(field->flags & ~(VMS_NONE | VMS_MUST_EXIST))) { > n_elems = 0; > } else if (field->flags & VMS_ARRAY) { > n_elems = field->num; > @@ -107,6 +107,9 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, > } > } > field++; > + } else if (field->flags & VMS_MUST_EXIST) { > + fprintf(stderr, "Input validation failed: %s/%s\n", vmsd->name, field->name); > + return -1; I think your intent here is just to misuse the field_exist function pointer as a call for a different reason as a hook for a validator; is it really worth misusing it like that or is something more explicit worth it? Perhaps something passed an Error** so it could pass back what was wrong? > } > ret = vmstate_subsection_load(f, vmsd, opaque); > if (ret != 0) { > @@ -148,6 +151,11 @@ void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, > field->info->put(f, addr, size); > } > } > + } else { > + if (field->flags & VMS_MUST_EXIST) { > + fprintf(stderr, "Input validation failed: %s/%s\n", vmsd->name, field->name); > + assert(!(field->flags & VMS_MUST_EXIST)); Wrong message for the save side. Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK