Re: [Qemu-devel] [PATCH 2/5] igd-passthrough-i440FX: convert to realize()

[Cao jin]

On 12/19/2015 02:37 AM, Eduardo Habkost wrote:
> On Fri, Dec 18, 2015 at 07:03:49PM +0800, Cao jin wrote:
> > Signed-off-by: Cao jin <address@hidden>
> > ---
> >   hw/pci-host/piix.c | 16 +++++++++-------
> >   1 file changed, 9 insertions(+), 7 deletions(-)
> >
> > diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
> > index 715208b..e3840f0 100644
> > --- a/hw/pci-host/piix.c
> > +++ b/hw/pci-host/piix.c
> > @@ -761,7 +761,7 @@ static const IGDHostInfo igd_host_bridge_infos[] = {
> >       {0xa8, 4},  /* SNB: base of GTT stolen memory */
> >   };
> >
> > -static int host_pci_config_read(int pos, int len, uint32_t val)
> > +static int host_pci_config_read(int pos, int len, uint32_t val, Error **errp)
>
> You don't need the return value anymore, if you report errors
> through the errp parameter. The function can be void, now.

Ok, will modify that in next version, as many people mentioned in the 
other patch...

> >   {
> >       char path[PATH_MAX];
> >       int config_fd;
> > @@ -772,15 +772,18 @@ static int host_pci_config_read(int pos, int len, 
> > uint32_t val)
> >       int ret = 0;
> >
> >       if (rc >= size || rc < 0) {
> > +        error_setg(errp, "No such device");
> >           return -ENODEV;
> >       }
> >
> >       config_fd = open(path, O_RDWR);
> >       if (config_fd < 0) {
> > +        error_setg(errp, "No such device");
> >           return -ENODEV;
> >       }
> >
> >       if (lseek(config_fd, pos, SEEK_SET) != pos) {
> > +        error_setg(errp, "lseek err: %s", strerror(errno));
>
> What about error_setg_errno()?

Ok, I am not conscious that there exist error_setg_errno() :p

> >           ret = -errno;
> >           goto out;
> >       }
> > @@ -789,13 +792,14 @@ static int host_pci_config_read(int pos, int len, 
> > uint32_t val)
> >       } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
> >       if (rc != len) {
> >           ret = -errno;
> > +        error_setg(errp, "read err: %s", strerror(errno));
>
> Same here.
OK.
> >       }
> >   out:
> >       close(config_fd);
> >       return ret;
> >   }
> >
> > -static int igd_pt_i440fx_initfn(struct PCIDevice *pci_dev)
> > +static void igd_pt_i440fx_realize(struct PCIDevice *pci_dev, Error **errp)
> >   {
> >       uint32_t val = 0;
> >       int rc, i, num;
> > @@ -805,14 +809,12 @@ static int igd_pt_i440fx_initfn(struct PCIDevice *pci_dev)
> >       for (i = 0; i < num; i++) {
> >           pos = igd_host_bridge_infos[i].offset;
> >           len = igd_host_bridge_infos[i].len;
> > -        rc = host_pci_config_read(pos, len, val);
> > +        rc = host_pci_config_read(pos, len, val, errp);
> >           if (rc) {
>
> The usual pattern for error checking and propagation is:
>
>      Error *err;
>      host_pci_config_read(pos, len, val, &err);
>      if (err) {
>          error_propagate(errp, local_err);
>          return;
>      }

Yup. I see

> > -            return -ENODEV;
> > +            return;
> >           }
> >           pci_default_write_config(pci_dev, pos, val, len);
> >       }
> > -
> > -    return 0;
> >   }
> >
> >   static void igd_passthrough_i440fx_class_init(ObjectClass *klass, void *data)
> > @@ -820,7 +822,7 @@ static void igd_passthrough_i440fx_class_init(ObjectClass 
> > *klass, void *data)
> >       DeviceClass *dc = DEVICE_CLASS(klass);
> >       PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
> >
> > -    k->init = igd_pt_i440fx_initfn;
> > +    k->realize = igd_pt_i440fx_realize;
> >       dc->desc = "IGD Passthrough Host bridge";
> >   }
> >
> > --
> > 2.1.0

--
Yours Sincerely,

Cao Jin