On 11/29/2011 08:44 AM, Daniel P. Berrange wrote:
From: "Daniel P. Berrange" <berrange@redhat.com>
If we ensure that virNodeSuspendGetTargetMask always resets *bitmask to zero upon failure, there is no need for the powerMgmt_valid field.
* src/util/virnodesuspend.c: Ensure *bitmask is zero upon failure * src/conf/capabilities.c, src/conf/capabilities.h: Remove powerMgmt_valid field * src/qemu/qemu_capabilities.c: Remove powerMgmt_valid
I'm not sure about this one. This is a semantic change in the resulting XML.
- if (caps->host.powerMgmt_valid) { - /* The PM query was successful. */ - if (caps->host.powerMgmt) { - /* The host supports some PM features. */ - unsigned int pm = caps->host.powerMgmt; - virBufferAddLit(&xml, " <power_management>\n"); - while (pm) { - int bit = ffs(pm) - 1; - virBufferAsprintf(&xml, " <%s/>\n", - virCapsHostPMTargetTypeToString(bit)); - pm &= ~(1U << bit); - } - virBufferAddLit(&xml, " </power_management>\n"); - } else { - /* The host does not support any PM feature. */ - virBufferAddLit(&xml, " <power_management/>\n");
Before, we had three cases (and documented them!): no <power_management> in the XML - we could not query (or older server) explicit <power_management/> - we successfully queried, but lack power management explicit <power_management> with sub-elements - what features are supported
+ /* The PM query was successful. */ + if (caps->host.powerMgmt) { + /* The host supports some PM features. */ + unsigned int pm = caps->host.powerMgmt; + virBufferAddLit(&xml, " <power_management>\n"); + while (pm) { + int bit = ffs(pm) - 1; + virBufferAsprintf(&xml, " <%s/>\n", + virCapsHostPMTargetTypeToString(bit)); + pm &= ~(1U << bit); } + virBufferAddLit(&xml, " </power_management>\n"); + } else { + /* The host does not support any PM feature. */ + virBufferAddLit(&xml, " <power_management/>\n");
Whereas after the patch, we now _always_ output a form of <power_management>, thus collapsing 3 states into 2. On the other hand, what is a user going to do about the difference between the first two? There's nothing useful they can do by knowing whether a host lacks power management or whether libvirt lacked the ability to query power management; either way, it means they can't use power management API. So I'm 70-30 in favor of this patch. At any rate, ACK to the code, but you also need to update docs/formatcaps.html.in to match, if we agree to go with it. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org