Re: [Qemu-devel] [PATCH 2/7] coroutine: add x86 specific coroutine backend

[Kevin Wolf]

Am 13.03.2019 um 13:40 hat Paolo Bonzini geschrieben:
> This backend is faster (100ns vs 150ns per switch on my laptop), but
> especially it will be possible to add CET support to it.
> 
> Unlike the ucontext backend, it does not save any register state;
> all registers are clobbered in the CO_SWITCH asm, and as a result
> the compiler automatically saves/restores caller-save registers in
> qemu_coroutine_switch.  This however means that it does not have register
> mangling, which is nicely provided by glibc to the ucontext backend.
> 
> Signed-off-by: Paolo Bonzini <address@hidden>

Oops, I just sent a review for v1, please look there. There's at least
one bug here (misaligned stack), and a few other things I'd like to see
cleaned up.

Kevin