Re: [libvirt] [Patch V2] Fix initialization of current vcpus in libxl driver
On 05/24/2011 11:22 AM, Jim Fehlig wrote:
The cur_vcpus member of struct libxl_domain_build_info was
incorrectly
initialized to the number of vcpus, when it should have been interpreted
as a bitmap, where bit X corresponds to online/offline status of vcpuX.
To complicate matters, cur_vcpus is an int, so only 32 vcpus can be
set online. Add a check to ensure vcpus does not exceed this limit.
V2: Eric Blake noted a compilation pitfal when '1 << 32' on an int.
If you keep the V2 message in your commit log, then s/pitfal/pitfall/
(personally, I tend to drop V2 messages when pushing - they are handy
during review to point out what to look for, but once it is part of
history, I no longer care how many versions it took to get to the final
pushed version).
Account for vcpus == 32.
+ * as an int, but its' semantic is a bitmap of online vcpus,
so
s/its'/its/
(That is, drop the spurious apostrophe).
b_info->hvm = hvm;
b_info->max_vcpus = def->maxvcpus;
- b_info->cur_vcpus = def->vcpus;
+ if (def->vcpus == 32)
+ b_info->cur_vcpus = 1 << 31;
Still wrong. You want 32 bits, not one bit:
b_info->cur_vcpus = (uint32_t) -1;
+ else
+ b_info->cur_vcpus = (1 << def->vcpus) - 1;
if (def->clock.ntimers > 0 &&
def->clock.timers[0]->name == VIR_DOMAIN_TIMER_NAME_TSC) {
switch (def->clock.timers[0]->mode) {
ACK with those changes.
--
Eric Blake eblake(a)redhat.com +1-801-349-2682
Libvirt virtualization library http://libvirt.org
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