Eric Blake wrote:
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;
This works in the libxl driver since cur_vcpus is an int. But vcpu_avail is a long in xenxs/xen_sxpr.c and I'm hoping there is something better than the following approach diff --git a/src/xenxs/xen_sxpr.c b/src/xenxs/xen_sxpr.c index 4cebb21..dc000a8 100644 --- a/src/xenxs/xen_sxpr.c +++ b/src/xenxs/xen_sxpr.c @@ -2006,9 +2006,14 @@ xenFormatSxpr(virConnectPtr conn, virBufferAsprintf(&buf, "(vcpus %u)", def->maxvcpus); /* Computing the vcpu_avail bitmask works because MAX_VIRT_CPUS is either 32, or 64 on a platform where long is big enough. */ - if (def->vcpus < def->maxvcpus) - virBufferAsprintf(&buf, "(vcpu_avail %lu)", - def->vcpus == 32 ? 1 << 31 : (1UL << def->vcpus) - 1); + if (def->vcpus < def->maxvcpus) { + if (sizeof(long) == 4 && def->vcpus == 32) + virBufferAsprintf(&buf, "(vcpu_avail %lu)", 1UL << 31); + else if (sizeof(long) == 8 && def->vcpus == 64) + virBufferAsprintf(&buf, "(vcpu_avail %lu)", 1UL << 63); + else + virBufferAsprintf(&buf, "(vcpu_avail %lu)", (1UL << def->vcpus) - 1); + } if (def->cpumask) { char *ranges = virDomainCpuSetFormat(def->cpumask, def->cpumasklen); Suggestions? Thanks, Jim