Re: [libvirt] [PATCHv7 3/4] libvirt/qemu - check address confliction before addition.

On Tue, 29 Mar 2011 10:41:57 +0800 Hu Tao <hutao(a)cn.fujitsu.com&gt; wrote: > On Fri, Mar 25, 2011 at 05:17:03PM +0900, KAMEZAWA Hiroyuki wrote: > > >From 638341bdf3eaac824e36d265e134608279750049 Mon Sep 17 00:00:00 2001 > > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu(a)jp.fujitsu.com&gt; > > Date: Fri, 25 Mar 2011 17:10:58 +0900 > > Subject: [PATCHv7 3/4] libvirt/qemu - check address confliction before addition. > > > > qemuDomainAttachDevicePersistent() calls qemuDomainAssignPCIAddresses() > > and virDomainDefAddImplicitControllers() at the end of its call. > > > > But PCI/Drive address confliction checks are > > PCI - confliction will be found but error report is not verbose. > > Drive - never done. > > > > For example, you can add following (unusual) 2 devices without errors. > > > > <disk type='file' device='disk'> > > <driver name='qemu' type='raw'/> > > <source file='/var/lib/libvirt/images/test3.img'/> > > <target dev="sdx" bus='scsi'/> > > <address type='drive' controller='0' bus='0' unit='0'/> > > </disk> > > > > <disk type='file' device='disk'> > > <driver name='qemu' type='raw'/> > > <source file='/var/lib/libvirt/images/test3.img'/> > > <target dev="sdy" bus='scsi'/> > > <address type='drive' controller='0' bus='0' unit='0'/> > > </disk> > > > > It's better to check drive address confliction before addition. > > > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu(a)jp.fujitsu.com&gt; > > --- > > src/conf/domain_conf.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++ > > src/conf/domain_conf.h | 2 + > > src/libvirt_private.syms | 1 + > > src/qemu/qemu_driver.c | 9 +++++++ > > 4 files changed, 71 insertions(+), 0 deletions(-) > > > > diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c > > index 3e3f342..4a54f62 100644 > > --- a/src/conf/domain_conf.c > > +++ b/src/conf/domain_conf.c > > @@ -1287,6 +1287,65 @@ void virDomainDefClearDeviceAliases(virDomainDefPtr def) > > virDomainDeviceInfoIterate(def, virDomainDeviceInfoClearAlias, NULL); > > } > > > > +static int virDomainDeviceAddressMatch(virDomainDefPtr def ATTRIBUTE_UNUSED, > > + virDomainDeviceInfoPtr info, > > + void *opaque) > > +{ > > + virDomainDeviceInfoPtr checked = opaque; > > + /* skip to check confliction of alias */ > > + if (info->type != checked->type) > > + return 0; > > + if (info->alias && checked->alias && strcmp(info->alias, checked->alias)) > > !STREQ instead of strcmp > ok. > > + return -1; > > + if (!memcmp(&info->addr, &checked->addr, sizeof(info->addr))) > > Is it safe to memcmp an union like this? In the cases members of an > union are of different sizes, and we intent to memcmp an union member > that has a smaller size than the other members, then data in space > not used by the union member to be compared is also compared. This is > not a desired result. As far as I checked, it's zero cleared at allocation. Hmm, making this function bigger ?