On Wed, 9 Nov 2016 18:36:20 +0000
Daniel Oram <daniel.o...@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.o...@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.william...@redhat.com>
Can anyone take this for 2.8? Thanks,
Alex
