Re: [PATCH v2 6/9] spapr_pci: add spapr msi read method

[Li Qiang]

David Gibson <david@gibson.dropbear.id.au> 于2020年6月25日周四 上午10:09写道：
>
> On Thu, Jun 25, 2020 at 12:25:20AM +0530, P J P wrote:
> > From: Prasad J Pandit <pjp@fedoraproject.org>
> >
> > Add spapr msi mmio read method to avoid NULL pointer dereference
> > issue.
> >
> > Reported-by: Lei Sun <slei.casper@gmail.com>
> > Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
>

Reviewed-by: Li Qiang <liq3ea@gmail.com>

> Acked-by: David Gibson <david@gibson.dropbear.id.au>
>
> > ---
> >  hw/ppc/spapr_pci.c | 13 +++++++++++--
> >  1 file changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
> > index 329002ac04..7033352834 100644
> > --- a/hw/ppc/spapr_pci.c
> > +++ b/hw/ppc/spapr_pci.c
> > @@ -52,6 +52,7 @@
> >  #include "sysemu/kvm.h"
> >  #include "sysemu/hostmem.h"
> >  #include "sysemu/numa.h"
> > +#include "qemu/log.h"
> >
> >  /* Copied from the kernel arch/powerpc/platforms/pseries/msi.c */
> >  #define RTAS_QUERY_FN           0
> > @@ -738,6 +739,12 @@ static PCIINTxRoute spapr_route_intx_pin_to_irq(void 
> > *opaque, int pin)
> >      return route;
> >  }
> >
> > +static uint64_t spapr_msi_read(void *opaque, hwaddr addr, unsigned size)
> > +{
> > +    qemu_log_mask(LOG_UNIMP, "%s not implemented\n", __func__);
> > +    return 0;
> > +}
> > +
> >  /*
> >   * MSI/MSIX memory region implementation.
> >   * The handler handles both MSI and MSIX.
> > @@ -755,8 +762,10 @@ static void spapr_msi_write(void *opaque, hwaddr addr,
> >  }
> >
> >  static const MemoryRegionOps spapr_msi_ops = {
> > -    /* There is no .read as the read result is undefined by PCI spec */
> > -    .read = NULL,
> > +    /* .read result is undefined by PCI spec
> > +     * define .read method to avoid assert failure in memory_region_init_io
> > +     */
> > +    .read = spapr_msi_read,
> >      .write = spapr_msi_write,
> >      .endianness = DEVICE_LITTLE_ENDIAN
> >  };
>
> --
> David Gibson                    | I'll have my music baroque, and my code
> david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
>                                 | _way_ _around_!
> http://www.ozlabs.org/~dgibson