Re: [Qemu-devel] [PATCH] target-arm: Bug fix in filling the cp_regs hashtable

[Abdallah Bouassida <abdallah.bouassida@lauterbach.com>]

Oh, I see!
Thanks for the details!

Regards,
Abdallah

Le 6/16/2017 à 3:51 PM, Peter Maydell a écrit :
> On 16 June 2017 at 15:42, Abdallah Bouassida
> <abdallah.bouassida@lauterbach.com> wrote:
>> Check if the CPU supports AARCH64 before adding  the 64bit view of
>> the coprocessor's register to the cp_regs hashtable.
>>
>> Signed-off-by: Abdallah Bouassida <abdallah.bouassida@lauterbach.com>
>> ---
>> Bug description: if a register has the .state = ARM_CP_STATE_BOTH, its 64bit
>> view will be added to the hashtable even if the CPU is not 64bit.
> This is deliberate and required. Where the AArch64 and AArch32
> states both have a register which shares underlying architectural
> state, QEMU chooses to implement migration of that state usually
> via the AArch64 version's ARMCPRegInfo struct. If the AArch64
> version is not included in the hashtable for an AArch32-only
> CPU then the state of the 32-bit register won't be migrated.
> The AArch64 register is of course invisible to the guest because
> it is only accessible via 64-bit instructions, but it's used
> during migration.
>
> thanks
> -- PMM