[PATCH 0/2] hw/sparc/leon3: Fixes for the AHB/APB bridge

[PATCH 0/2] hw/sparc/leon3: Fixes for the AHB/APB bridge

[Philippe Mathieu-Daudé]

Two trivial fixes after reading Jiri comment:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg654994.html

  "The plug&play area must support byte accesses,
  which is used by the RTEMS grlib scanning functions..."

Regards,

Phil.

Philippe Mathieu-Daudé (2):
  hw/misc/grlib_ahb_apb_pnp: Avoid crash when writing to PnP registers
  hw/misc/grlib_ahb_apb_pnp: Fix 8-bit accesses

 hw/misc/grlib_ahb_apb_pnp.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

-- 
2.21.0

[PATCH 1/2] hw/misc/grlib_ahb_apb_pnp: Avoid crash when writing to PnP registers

[Philippe Mathieu-Daudé]

Guests can crash QEMU when writting to PnP registers:

  $ echo 'writeb 0x800ff042 69' | qemu-system-sparc -M leon3_generic -S -bios /etc/magic -qtest stdio
  [I 1571938309.932255] OPENED
  [R +0.063474] writeb 0x800ff042 69
  Segmentation fault (core dumped)

  (gdb) bt
  #0  0x0000000000000000 in  ()
  #1  0x0000555f4bcdf0bc in memory_region_write_with_attrs_accessor (mr=0x555f4d7be8c0, addr=66, value=0x7fff07d00f08, size=1, shift=0, mask=255, attrs=...) at memory.c:503
  #2  0x0000555f4bcdf185 in access_with_adjusted_size (addr=66, value=0x7fff07d00f08, size=1, access_size_min=1, access_size_max=4, access_fn=0x555f4bcdeff4 <memory_region_write_with_attrs_accessor>, mr=0x555f4d7be8c0, attrs=...) at memory.c:539
  #3  0x0000555f4bce2243 in memory_region_dispatch_write (mr=0x555f4d7be8c0, addr=66, data=69, op=MO_8, attrs=...) at memory.c:1489
  #4  0x0000555f4bc80b20 in flatview_write_continue (fv=0x555f4d92c400, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1, addr1=66, l=1, mr=0x555f4d7be8c0) at exec.c:3161
  #5  0x0000555f4bc80c65 in flatview_write (fv=0x555f4d92c400, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1) at exec.c:3201
  #6  0x0000555f4bc80fb0 in address_space_write (as=0x555f4d7aa460, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1) at exec.c:3291
  #7  0x0000555f4bc8101d in address_space_rw (as=0x555f4d7aa460, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1, is_write=true) at exec.c:3301
  #8  0x0000555f4bcdb388 in qtest_process_command (chr=0x555f4c2ed7e0 <qtest_chr>, words=0x555f4db0c5d0) at qtest.c:432

Instead of crashing, log the access as unimplemented.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/misc/grlib_ahb_apb_pnp.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/hw/misc/grlib_ahb_apb_pnp.c b/hw/misc/grlib_ahb_apb_pnp.c
index 7338461694..f3c015d2c3 100644
--- a/hw/misc/grlib_ahb_apb_pnp.c
+++ b/hw/misc/grlib_ahb_apb_pnp.c
@@ -22,6 +22,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/log.h"
 #include "hw/sysbus.h"
 #include "hw/misc/grlib_ahb_apb_pnp.h"
 
@@ -231,8 +232,15 @@ static uint64_t grlib_apb_pnp_read(void *opaque, hwaddr offset, unsigned size)
     return apb_pnp->regs[offset >> 2];
 }
 
+static void grlib_apb_pnp_write(void *opaque, hwaddr addr,
+                                uint64_t val, unsigned size)
+{
+    qemu_log_mask(LOG_UNIMP, "%s not implemented\n", __func__);
+}
+
 static const MemoryRegionOps grlib_apb_pnp_ops = {
     .read       = grlib_apb_pnp_read,
+    .write      = grlib_apb_pnp_write,
     .endianness = DEVICE_BIG_ENDIAN,
 };
 
-- 
2.21.0

[PATCH 2/2] hw/misc/grlib_ahb_apb_pnp: Fix 8-bit accesses

[Philippe Mathieu-Daudé]

The Plug & Play region of the AHB/APB bridge can be accessed
by various word size, however the implementation is clearly
restricted to 32-bit:

  static uint64_t grlib_apb_pnp_read(void *opaque, hwaddr offset, unsigned size)
  {
      APBPnp *apb_pnp = GRLIB_APB_PNP(opaque);

      return apb_pnp->regs[offset >> 2];
  }

Set the MemoryRegionOps::impl min/max fields to 32-bit, so
memory.c::access_with_adjusted_size() can adjust when the
access is not 32-bit.

This is required to run RTEMS on leon3, the grlib scanning
functions do byte accesses.

Reported-by: Jiri Gaisler <jiri@gaisler.se>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/misc/grlib_ahb_apb_pnp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/misc/grlib_ahb_apb_pnp.c b/hw/misc/grlib_ahb_apb_pnp.c
index f3c015d2c3..e230e25363 100644
--- a/hw/misc/grlib_ahb_apb_pnp.c
+++ b/hw/misc/grlib_ahb_apb_pnp.c
@@ -242,6 +242,10 @@ static const MemoryRegionOps grlib_apb_pnp_ops = {
     .read       = grlib_apb_pnp_read,
     .write      = grlib_apb_pnp_write,
     .endianness = DEVICE_BIG_ENDIAN,
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
 };
 
 static void grlib_apb_pnp_realize(DeviceState *dev, Error **errp)
-- 
2.21.0

Re: [PATCH 1/2] hw/misc/grlib_ahb_apb_pnp: Avoid crash when writing to PnP registers

[KONRAD Frederic]

Hi Philippe,

Le 10/25/19 à 1:01 PM, Philippe Mathieu-Daudé a écrit :
> Guests can crash QEMU when writting to PnP registers:
> 
>    $ echo 'writeb 0x800ff042 69' | qemu-system-sparc -M leon3_generic -S -bios /etc/magic -qtest stdio
>    [I 1571938309.932255] OPENED
>    [R +0.063474] writeb 0x800ff042 69
>    Segmentation fault (core dumped)
> 
>    (gdb) bt
>    #0  0x0000000000000000 in  ()
>    #1  0x0000555f4bcdf0bc in memory_region_write_with_attrs_accessor (mr=0x555f4d7be8c0, addr=66, value=0x7fff07d00f08, size=1, shift=0, mask=255, attrs=...) at memory.c:503
>    #2  0x0000555f4bcdf185 in access_with_adjusted_size (addr=66, value=0x7fff07d00f08, size=1, access_size_min=1, access_size_max=4, access_fn=0x555f4bcdeff4 <memory_region_write_with_attrs_accessor>, mr=0x555f4d7be8c0, attrs=...) at memory.c:539
>    #3  0x0000555f4bce2243 in memory_region_dispatch_write (mr=0x555f4d7be8c0, addr=66, data=69, op=MO_8, attrs=...) at memory.c:1489
>    #4  0x0000555f4bc80b20 in flatview_write_continue (fv=0x555f4d92c400, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1, addr1=66, l=1, mr=0x555f4d7be8c0) at exec.c:3161
>    #5  0x0000555f4bc80c65 in flatview_write (fv=0x555f4d92c400, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1) at exec.c:3201
>    #6  0x0000555f4bc80fb0 in address_space_write (as=0x555f4d7aa460, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1) at exec.c:3291
>    #7  0x0000555f4bc8101d in address_space_rw (as=0x555f4d7aa460, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1, is_write=true) at exec.c:3301
>    #8  0x0000555f4bcdb388 in qtest_process_command (chr=0x555f4c2ed7e0 <qtest_chr>, words=0x555f4db0c5d0) at qtest.c:432
> 
> Instead of crashing, log the access as unimplemented.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

oops, thanks for that :).

Reviewed-by: KONRAD Frederic <frederic.konrad@adacore.com>

> ---
>   hw/misc/grlib_ahb_apb_pnp.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/hw/misc/grlib_ahb_apb_pnp.c b/hw/misc/grlib_ahb_apb_pnp.c
> index 7338461694..f3c015d2c3 100644
> --- a/hw/misc/grlib_ahb_apb_pnp.c
> +++ b/hw/misc/grlib_ahb_apb_pnp.c
> @@ -22,6 +22,7 @@
>    */
>   
>   #include "qemu/osdep.h"
> +#include "qemu/log.h"
>   #include "hw/sysbus.h"
>   #include "hw/misc/grlib_ahb_apb_pnp.h"
>   
> @@ -231,8 +232,15 @@ static uint64_t grlib_apb_pnp_read(void *opaque, hwaddr offset, unsigned size)
>       return apb_pnp->regs[offset >> 2];
>   }
>   
> +static void grlib_apb_pnp_write(void *opaque, hwaddr addr,
> +                                uint64_t val, unsigned size)
> +{
> +    qemu_log_mask(LOG_UNIMP, "%s not implemented\n", __func__);
> +}
> +
>   static const MemoryRegionOps grlib_apb_pnp_ops = {
>       .read       = grlib_apb_pnp_read,
> +    .write      = grlib_apb_pnp_write,
>       .endianness = DEVICE_BIG_ENDIAN,
>   };
>   
> 

Re: [PATCH 2/2] hw/misc/grlib_ahb_apb_pnp: Fix 8-bit accesses

[KONRAD Frederic]

Le 10/25/19 à 1:01 PM, Philippe Mathieu-Daudé a écrit :
> The Plug & Play region of the AHB/APB bridge can be accessed
> by various word size, however the implementation is clearly
> restricted to 32-bit:
> 
>    static uint64_t grlib_apb_pnp_read(void *opaque, hwaddr offset, unsigned size)
>    {
>        APBPnp *apb_pnp = GRLIB_APB_PNP(opaque);
> 
>        return apb_pnp->regs[offset >> 2];
>    }
> 
> Set the MemoryRegionOps::impl min/max fields to 32-bit, so
> memory.c::access_with_adjusted_size() can adjust when the
> access is not 32-bit.
> 
> This is required to run RTEMS on leon3, the grlib scanning
> functions do byte accesses.
> 
> Reported-by: Jiri Gaisler <jiri@gaisler.se>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>   hw/misc/grlib_ahb_apb_pnp.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/hw/misc/grlib_ahb_apb_pnp.c b/hw/misc/grlib_ahb_apb_pnp.c
> index f3c015d2c3..e230e25363 100644
> --- a/hw/misc/grlib_ahb_apb_pnp.c
> +++ b/hw/misc/grlib_ahb_apb_pnp.c
> @@ -242,6 +242,10 @@ static const MemoryRegionOps grlib_apb_pnp_ops = {
>       .read       = grlib_apb_pnp_read,
>       .write      = grlib_apb_pnp_write,
>       .endianness = DEVICE_BIG_ENDIAN,
> +    .impl = {
> +        .min_access_size = 4,
> +        .max_access_size = 4,
> +    },
>   };
>   
>   static void grlib_apb_pnp_realize(DeviceState *dev, Error **errp)
> 

Reviewed-by: KONRAD Frederic <frederic.konrad@adacore.com>

Thanks

Re: [PATCH 1/2] hw/misc/grlib_ahb_apb_pnp: Avoid crash when writing to PnP registers

[Laurent Vivier]

Le 25/10/2019 à 13:01, Philippe Mathieu-Daudé a écrit :
> Guests can crash QEMU when writting to PnP registers:
> 
>   $ echo 'writeb 0x800ff042 69' | qemu-system-sparc -M leon3_generic -S -bios /etc/magic -qtest stdio
>   [I 1571938309.932255] OPENED
>   [R +0.063474] writeb 0x800ff042 69
>   Segmentation fault (core dumped)
> 
>   (gdb) bt
>   #0  0x0000000000000000 in  ()
>   #1  0x0000555f4bcdf0bc in memory_region_write_with_attrs_accessor (mr=0x555f4d7be8c0, addr=66, value=0x7fff07d00f08, size=1, shift=0, mask=255, attrs=...) at memory.c:503
>   #2  0x0000555f4bcdf185 in access_with_adjusted_size (addr=66, value=0x7fff07d00f08, size=1, access_size_min=1, access_size_max=4, access_fn=0x555f4bcdeff4 <memory_region_write_with_attrs_accessor>, mr=0x555f4d7be8c0, attrs=...) at memory.c:539
>   #3  0x0000555f4bce2243 in memory_region_dispatch_write (mr=0x555f4d7be8c0, addr=66, data=69, op=MO_8, attrs=...) at memory.c:1489
>   #4  0x0000555f4bc80b20 in flatview_write_continue (fv=0x555f4d92c400, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1, addr1=66, l=1, mr=0x555f4d7be8c0) at exec.c:3161
>   #5  0x0000555f4bc80c65 in flatview_write (fv=0x555f4d92c400, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1) at exec.c:3201
>   #6  0x0000555f4bc80fb0 in address_space_write (as=0x555f4d7aa460, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1) at exec.c:3291
>   #7  0x0000555f4bc8101d in address_space_rw (as=0x555f4d7aa460, addr=2148528194, attrs=..., buf=0x7fff07d01120 "E", len=1, is_write=true) at exec.c:3301
>   #8  0x0000555f4bcdb388 in qtest_process_command (chr=0x555f4c2ed7e0 <qtest_chr>, words=0x555f4db0c5d0) at qtest.c:432
> 
> Instead of crashing, log the access as unimplemented.
> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/misc/grlib_ahb_apb_pnp.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/hw/misc/grlib_ahb_apb_pnp.c b/hw/misc/grlib_ahb_apb_pnp.c
> index 7338461694..f3c015d2c3 100644
> --- a/hw/misc/grlib_ahb_apb_pnp.c
> +++ b/hw/misc/grlib_ahb_apb_pnp.c
> @@ -22,6 +22,7 @@
>   */
>  
>  #include "qemu/osdep.h"
> +#include "qemu/log.h"
>  #include "hw/sysbus.h"
>  #include "hw/misc/grlib_ahb_apb_pnp.h"
>  
> @@ -231,8 +232,15 @@ static uint64_t grlib_apb_pnp_read(void *opaque, hwaddr offset, unsigned size)
>      return apb_pnp->regs[offset >> 2];
>  }
>  
> +static void grlib_apb_pnp_write(void *opaque, hwaddr addr,
> +                                uint64_t val, unsigned size)
> +{
> +    qemu_log_mask(LOG_UNIMP, "%s not implemented\n", __func__);
> +}
> +
>  static const MemoryRegionOps grlib_apb_pnp_ops = {
>      .read       = grlib_apb_pnp_read,
> +    .write      = grlib_apb_pnp_write,
>      .endianness = DEVICE_BIG_ENDIAN,
>  };
>  
> 

Applied to my trivial-patches branch.

Thanks,
Laurent

Re: [PATCH 2/2] hw/misc/grlib_ahb_apb_pnp: Fix 8-bit accesses

[Laurent Vivier]

Le 25/10/2019 à 13:01, Philippe Mathieu-Daudé a écrit :
> The Plug & Play region of the AHB/APB bridge can be accessed
> by various word size, however the implementation is clearly
> restricted to 32-bit:
> 
>   static uint64_t grlib_apb_pnp_read(void *opaque, hwaddr offset, unsigned size)
>   {
>       APBPnp *apb_pnp = GRLIB_APB_PNP(opaque);
> 
>       return apb_pnp->regs[offset >> 2];
>   }
> 
> Set the MemoryRegionOps::impl min/max fields to 32-bit, so
> memory.c::access_with_adjusted_size() can adjust when the
> access is not 32-bit.
> 
> This is required to run RTEMS on leon3, the grlib scanning
> functions do byte accesses.
> 
> Reported-by: Jiri Gaisler <jiri@gaisler.se>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/misc/grlib_ahb_apb_pnp.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/hw/misc/grlib_ahb_apb_pnp.c b/hw/misc/grlib_ahb_apb_pnp.c
> index f3c015d2c3..e230e25363 100644
> --- a/hw/misc/grlib_ahb_apb_pnp.c
> +++ b/hw/misc/grlib_ahb_apb_pnp.c
> @@ -242,6 +242,10 @@ static const MemoryRegionOps grlib_apb_pnp_ops = {
>      .read       = grlib_apb_pnp_read,
>      .write      = grlib_apb_pnp_write,
>      .endianness = DEVICE_BIG_ENDIAN,
> +    .impl = {
> +        .min_access_size = 4,
> +        .max_access_size = 4,
> +    },
>  };
>  
>  static void grlib_apb_pnp_realize(DeviceState *dev, Error **errp)
> 

Applied to my trivial-patches branch.

Thanks,
Laurent