Re: [KVM PATCH v8 3/3] KVM: add iosignalfd support

Michael S. Tsirkin
2009-06-23T08:57:15Z

On Thu, Jun 18, 2009 at 08:30:46PM -0400, Gregory Haskins wrote:
> +static int
> +iosignalfd_group_in_range(struct kvm_io_device *this, gpa_t addr, int len,
> + int is_write)
> +{
> + struct _iosignalfd_group *p = to_group(this);
> +
> + return ((addr >= p->addr && (addr < p->addr + p->length)));
> +}

I think I see a problem here. For virtio, we do not necessarily want all
virtqueues for a device to live in kernel: there might be control
virtqueues that we want to leave in userspace. Since this claims all
writes to a specific address, the signal never makes it to userspace.