Re: [Qemu-devel] [PATCH 14/22] nvram/ds1225y: Convert sysbus init function to realize function

[Philippe Mathieu-Daudé]

Hi Peter,

On 20/11/18 15:51, Peter Maydell wrote:
> On 19 November 2018 at 12:08, Mao Zhongyi
> <address@hidden> wrote:
> > Use DeviceClass rather than SysBusDeviceClass in
> > nvram_sysbus_class_init().
> >
> > Cc: address@hidden
> > Cc: address@hidden
> >
> > Signed-off-by: Mao Zhongyi <address@hidden>
> > Signed-off-by: Zhang Shengju <address@hidden>
> > ---
> >   hw/nvram/ds1225y.c | 12 +++++-------
> >   1 file changed, 5 insertions(+), 7 deletions(-)
> >
> > diff --git a/hw/nvram/ds1225y.c b/hw/nvram/ds1225y.c
> > index ad7345f288..b6ef463db0 100644
> > --- a/hw/nvram/ds1225y.c
> > +++ b/hw/nvram/ds1225y.c
> > @@ -25,6 +25,7 @@
> >   #include "qemu/osdep.h"
> >   #include "hw/sysbus.h"
> >   #include "trace.h"
> > +#include "qemu/error-report.h"
> >
> >   typedef struct {
> >       MemoryRegion iomem;
> > @@ -113,7 +114,7 @@ typedef struct {
> >       NvRamState nvram;
> >   } SysBusNvRamState;
> >
> > -static int nvram_sysbus_initfn(SysBusDevice *dev)
> > +static void nvram_sysbus_realize(DeviceState *dev, Error **errp)
> >   {
> >       SysBusNvRamState *sys = DS1225Y(dev);
> >       NvRamState *s = &sys->nvram;
> > @@ -123,20 +124,18 @@ static int nvram_sysbus_initfn(SysBusDevice *dev)
> >
> >       memory_region_init_io(&s->iomem, OBJECT(s), &nvram_ops, s,
> >                             "nvram", s->chip_size);
> > -    sysbus_init_mmio(dev, &s->iomem);
> > +    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
> >
> >       /* Read current file */
> >       file = s->filename ? fopen(s->filename, "rb") : NULL;
> >       if (file) {
> >           /* Read nvram contents */
> >           if (fread(s->contents, s->chip_size, 1, file) != 1) {
> > -            printf("nvram_sysbus_initfn: short read\n");
> > +            error_report("nvram_sysbus_realize: short read");
>
> It seems a bit odd that we don't make this cause the
> device to fail its realize method, though I suppose
> it was not previously.

I think the case where the file length is <= chip_size is OK, since the 
contents buffer is zero-allocated.

Now for the other case when length > chip_size, you are right we 
shouldn't ignore it and throw an error.

However this is not related to this patch and should be addressed in a 
different patch, so for this patch:
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

This file is named ds1225y but is rather a generic way to byte-access a 
file (except the default chip_size which is 8kB for the DS1225Y).
Is there a more up-to-date way to do that nowaday?

> >           }
> >           fclose(file);
> >       }
> >       nvram_post_load(s, 0);
> > -
> > -    return 0;
> >   }
> >
> >   static Property nvram_sysbus_properties[] = {
> > @@ -148,9 +147,8 @@ static Property nvram_sysbus_properties[] = {
> >   static void nvram_sysbus_class_init(ObjectClass *klass, void *data)
> >   {
> >       DeviceClass *dc = DEVICE_CLASS(klass);
> > -    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
> >
> > -    k->init = nvram_sysbus_initfn;
> > +    dc->realize = nvram_sysbus_realize;
> >       dc->vmsd = &vmstate_nvram;
> >       dc->props = nvram_sysbus_properties;
> >   }
> > --
> > 2.17.1
>
> thanks
> -- PMM