[v2] memory: assert and define MemoryRegionOps callbacks

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

Posted by P J P 5 years, 7 months ago

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>
---
 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
 };
-- 
2.26.2

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

Posted by David Gibson 5 years, 7 months ago

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>

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

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

Posted by Li Qiang 5 years, 7 months ago

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