Re: [Qemu-devel] Atomic Instructions - comments please

[Paolo Bonzini]

On 15/12/2014 14:28, Peter Maydell wrote:
> Personally I would start out with this approach. We're going to
> need a "do this whole sequence atomically wrt other guest CPUs"
> mechanism anyway, so it's not implementing something we wouldn't
> otherwise need. And it's the simple thing to do. It's certainly
> possible to do a more architecturally correct ld/st exclusive
> implementation along the lines of how we manage TB invalidation
> with the dirty bitmap, but if we can do without it then we
> should try to keep the scope of this project constrained: it's
> a big enough job as it is.

How would "add a mutex" work unless you add a mutex or CAS to each and
every qemu_st operation?

Paolo