On 13/10/25 18:10, Peter Maydell wrote:
In commit bd8e9ddf6f6 ("target/arm: Refactor default generic timer
frequency handling") we changed how we initialized the generic timer
frequency as reported in the CNTFRQ_EL0 register. As part of that,
we chanegd the linux-user version of the CNTFRQ_EL0 sysreg from
"changed"
having a constant value set at compile time through the .resetvalue
field to having a reset value which we compute in a .resetfn.
This accidentally broke the reading of CNTFRQ_EL0 in linux-user mode,
because the cpreg is marked as ARM_CP_CONST, which means we translate
it as a read of the compile-time constant value in the .resetvalue
field. This is now zero, so userspace sees a 0 frequency value.
Fix the bug by dropping the ARM_CP_CONST marking. This will cause us
to translate the read as a load of the value from the CPU state
struct cp15.c14_cntfrq field, which is where the real frequency value
now lives.
Cc: [email protected]
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3159
Fixes: bd8e9ddf6f6 ("target/arm: Refactor default generic timer frequency
handling")
Signed-off-by: Peter Maydell <[email protected]>
---
target/arm/helper.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
