| Message ID | 46a04f3ac5b60b26d2eff291e30747cd2c591233.1478712729.git.daniel.oram@gmail.com |
|---|---|
| State | New |
| Headers | show |
On Wed, 9 Nov 2016 18:36:20 +0000 Daniel Oram <daniel.oram@gmail.com> wrote: > 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. > nit, wrap your commit log at ~70 chars > Signed-off-by: Daniel Oram <daniel.oram@gmail.com> > --- > hw/core/qdev-properties.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > > diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c > index 311af6d..ed0d5b0 100644 > --- a/hw/core/qdev-properties.c > +++ b/hw/core/qdev-properties.c > @@ -705,13 +705,21 @@ 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); > } Works for me, note that slot and function are actually 5 bits and 3 bits respectively, so an address ending in "ff.f" can easily be recognized as invalid to the user, the highest actual address would be "ffff:ff:1f.7". Reviewed-by: Alex Williamson <alex.williamson@redhat.com> Can anyone take this for 2.8? Thanks, Alex
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c index 311af6d..ed0d5b0 100644 --- a/hw/core/qdev-properties.c +++ b/hw/core/qdev-properties.c @@ -705,13 +705,21 @@ 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); }
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> --- hw/core/qdev-properties.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)