[Qemu-devel] Re: [PATCH] gdbstub: x86: Switch 64/32 bit registers dynamically

[Jan Kiszka <jan.kiszka@siemens.com>]

Jan Kiszka wrote:
> Commit 56aebc891674cd2d07b3f64183415697be200084 changed gdbstub in way
> that debugging 32 or 16-bit guest code is no longer possible with qemu
> for x86_64 guest CPUs. Since that commit, qemu only provides registers
> sets for 64-bit, forcing current and foreseeable gdb to also switch its
> architecture to 64-bit. And this breaks if the inferior is 32 or 16 bit.
> 
> No question, this is a gdb issue. But, as it was confirmed in several
> discusssions with gdb people, it is a non-trivial thing to fix. So until
> qemu finds a gdb version attach with a rework x86 support, we have to
> work around it by switching the register layout as the guest switches
> its execution mode between 16/32 and 64 bit.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
> Sent to qemu-kvm for inclusion on Avi's request as this workaround is
> still disliked upstream.

Sorry, mistyped the list address.

Jan

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