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From: Paul Brook <paul@codesourcery.com>
Subject: Re: [Qemu-devel] [PATCH] gdbstub: x86: Switch 64/32 bit registers
	dynamically
Date: Tue, 10 Nov 2009 13:35:08 +0000
References: <4AB26055.2060506@siemens.com>
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To: qemu-devel@nongnu.org
Cc: Jan Kiszka <jan.kiszka@siemens.com>, Marcelo Tosatti <mtosatti@redhat.com>, Abhishek Saksena <abhishek.saksena@intel.com>, Avi Kivity <avi@redhat.com>

> 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.

Again, absolutely not. Changing the register set reported to a connected gdb 
is *never* correct.  An option (possibly monitor command) to change the 
register set reported to gdb *before* a connection is establisted, that may be 
acceptable.

Paul