diff mbox series

[PATCH-for-10.0,2/2] hw/misc/aspeed_scu: Correct minimum access size for AST2500 / AST2600

Message ID 20250331230444.88295-3-philmd@linaro.org
State New
Headers show
Series hw/misc/aspeed_scu: Correct minimum access size for AST2500 / AST2600 | expand

Commit Message

Philippe Mathieu-Daudé March 31, 2025, 11:04 p.m. UTC 
From: Joel Stanley <joel@jms.id.au>

Guest code was performing a byte load to the SCU MMIO region, leading
to the guest code crashing (it should be using proper accessors, but
that is not Qemu's bug). Hardware and the documentation[1] both agree
that byte loads are okay, so change all of the aspeed SCU devices to
accept a minimum access size of 1.

[1] See the 'ARM Address Space Mapping' table in the ASPEED docs. This
is section 6.1 in the ast2400 and ast2700, and 7.1 in the ast2500 and
ast2600 datasheets.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2636
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Troy Lee <leetroy@gmail.com>
Message-ID: <20241118021820.4928-1-joel@jms.id.au>
[PMD: Rebased, only including SCU changes]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/misc/aspeed_scu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Andrew Jeffery April 1, 2025, 1:09 a.m. UTC | #1 
On Tue, 2025-04-01 at 01:04 +0200, Philippe Mathieu-Daudé wrote:
> From: Joel Stanley <joel@jms.id.au>
> 
> Guest code was performing a byte load to the SCU MMIO region, leading
> to the guest code crashing (it should be using proper accessors, but
> that is not Qemu's bug). Hardware and the documentation[1] both agree
> that byte loads are okay, so change all of the aspeed SCU devices to
> accept a minimum access size of 1.
> 
> [1] See the 'ARM Address Space Mapping' table in the ASPEED docs.
> This
> is section 6.1 in the ast2400 and ast2700, and 7.1 in the ast2500 and
> ast2600 datasheets.
> 
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2636
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> Reviewed-by: Troy Lee <leetroy@gmail.com>
> Message-ID: <20241118021820.4928-1-joel@jms.id.au>
> [PMD: Rebased, only including SCU changes]
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff mbox series

Patch

diff --git a/hw/misc/aspeed_scu.c b/hw/misc/aspeed_scu.c
index 6703f3f9691..1af1a35a081 100644
--- a/hw/misc/aspeed_scu.c
+++ b/hw/misc/aspeed_scu.c
@@ -443,7 +443,7 @@  static const MemoryRegionOps aspeed_ast2500_scu_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
     .impl.min_access_size = 4,
     .impl.max_access_size = 4,
-    .valid.min_access_size = 4,
+    .valid.min_access_size = 1,
     .valid.max_access_size = 4,
     .valid.unaligned = false,
 };
@@ -787,7 +787,7 @@  static const MemoryRegionOps aspeed_ast2600_scu_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
     .impl.min_access_size = 4,
     .impl.max_access_size = 4,
-    .valid.min_access_size = 4,
+    .valid.min_access_size = 1,
     .valid.max_access_size = 4,
     .valid.unaligned = false,
 };