qdev: Fix assert in PCI address property when used by vfio-pci

Allow the PCIHostDeviceAddress structure to work as the host property
in vfio-pci when it has it's default value of all fields set to ~0. In
this form the property indicates a non-existant device but given the
field bit sizes gets asserted as excess (and invalid) precision
overflows the string buffer. The BDF of an invalid device
"FFFF:FF:FF.F" is returned instead.

Signed-off-by: Daniel Oram <daniel.oram@gmail.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Message-Id: <71f06765c4ba16dcd71cbf78e877619948f04ed9.1478777270.git.daniel.oram@gmail.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This commit is contained in:
Daniel Oram 2016-11-10 12:42:07 +00:00 committed by Eduardo Habkost
parent 97e53cf82c
commit 00b8702581
1 changed files with 10 additions and 4 deletions

View File

@ -705,13 +705,19 @@ static void get_pci_host_devaddr(Object *obj, Visitor *v, const char *name,
DeviceState *dev = DEVICE(obj);
Property *prop = opaque;
PCIHostDeviceAddress *addr = qdev_get_prop_ptr(dev, prop);
char buffer[] = "xxxx:xx:xx.x";
char buffer[] = "ffff:ff:ff.f";
char *p = buffer;
int rc = 0;
rc = snprintf(buffer, sizeof(buffer), "%04x:%02x:%02x.%d",
addr->domain, addr->bus, addr->slot, addr->function);
assert(rc == sizeof(buffer) - 1);
/*
* Catch "invalid" device reference from vfio-pci and allow the
* default buffer representing the non-existant device to be used.
*/
if (~addr->domain || ~addr->bus || ~addr->slot || ~addr->function) {
rc = snprintf(buffer, sizeof(buffer), "%04x:%02x:%02x.%0d",
addr->domain, addr->bus, addr->slot, addr->function);
assert(rc == sizeof(buffer) - 1);
}
visit_type_str(v, name, &p, errp);
}