Eric Blake wrote:
On 05/24/2011 10:33 AM, Jim Fehlig wrote:
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 def->maxvcpus is 32, then:
+ if (sizeof(long) == 4 && def->vcpus == 32)
this conditional will never be reached (def->vcpus is less than def->maxvcpus).
So the existing ((1UL << def->vcpus) -1) never calls the non-portable 1UL<<32 (or 1UL<<64); so it never overflows.
Ok, so I just need to handle this in the libxl driver. I'll post a V2. Regards, Jim