Re: [Qemu-devel] Re: [PATCH] qemu/virtio: make wmb compiler barrier + comments

[Jamie Lokier]

Scott Tsai wrote:
> I do have a newbie question, when exactly would vrtio have to handle
> concurrent access from multiple threads?
> My current reading of the code suggests:
> 1. when CONFIG_IOTHREAD is true
> 2. when CONFIG_KVM is true and the guest machine has multiple CPUs

It's enough to have CONFIG_KVM with a single guest CPU, isn't it?

Because the guest CPU can still run concurrently with the I/O thread
on kvm, and the host may have multiple CPUs even though the guest does
not.

-- Jamie