On 05/24/2011 09:14 AM, Daniel Veillard wrote:
On Mon, May 23, 2011 at 04:43:19PM -0600, Eric Blake wrote:
On 05/23/2011 04:26 PM, Jim Fehlig wrote:
b_info->hvm = hvm; b_info->max_vcpus = def->maxvcpus; - b_info->cur_vcpus = def->vcpus; + b_info->cur_vcpus = (1 << def->vcpus) - 1;
That's a compilation pitfall if def->vcpus is exactly 32.
Shoot; xenFormatSxpr in xenxs/xen_sxpr.c has the same bug.
What would be the best way to fix ? cast to a larger int and recast the result or provide some kind of helper function for bitmaps ?
Maybe special-case: if (def->vcpus == 32) b_info->cur_vcpus = (uint32_t) -1; else b_info->cur_vcpus = (1 << def->vcpus) - 1; Or build it up differently (although it gets harder to read): b_info->cur_vcpus = ((1 << (def->vcpus - 1)) - 1) * 2 + 1; As long as we rework it to avoid the undefined overflow of 1 << 32, when we really just want 32 bits set. -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org