On 12/14/2012 06:35:12 AM, Alexander Graf wrote:
On 14.12.2012, at 03:12, Scott Wood wrote:
> If we access a register via the QEMU memory inspection commands
(e.g.
> "xp") rather than from guest code, we won't have a CPU context.
> Gracefully fail to access the register in that case, rather than
> crashing.
Can't we set cpu_single_env in the debug memory access case? I'm not
sure this is the only device with that problem, and by always having
cpu_single_env available we would completely get rid of the whole bug
category.
So, how would we go about doing this? cpu_single_env is declared as
thread-local storage. Even if there's some way to deliberately inspect
a different thread's local storage, I don't see how you'd get it to
work automatically without changing all those drivers (and are there
really that many that care about the CPU?) -- and we might break other
places that already check whether cpu_single_env is NULL.
FWIW, hw/pc.c does pretty much the same thing as this patch in
cpu_get_current_apic().
-Scott
