Thanks for your patch serials. I think they fix the true bug. But I have a little doubt on the fuzz allowance, pls have a see comment in line below. On Fri, Mar 30, 2012 at 11:56 PM, Eric Blake <eblake@redhat.com> wrote:
Commit 1b1402b introduced a regression. Since older libvirt versions would silently round memory up (until the previous patch), but populated current memory based on querying the guest, it was possible to have current > maximum by the amount of the rounding. Accept this fuzz factor, and silently clamp current down to maximum in that case, rather than failing to reparse XML for an existing VM.
* src/conf/domain_conf.c (virDomainDefParseXML): Don't reject existing XML. Based on a report by Zhou Peng. --- src/conf/domain_conf.c | 19 +++++++++++++++---- src/qemu/qemu_monitor_json.c | 2 +- 2 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 4caef6f..7c95920 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -7776,10 +7776,21 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps, goto error;
if (def->mem.cur_balloon > def->mem.max_balloon) { - virDomainReportError(VIR_ERR_XML_ERROR, - _("current memory '%lluk' exceeds maximum '%lluk'"), - def->mem.cur_balloon, def->mem.max_balloon); - goto error; + /* Older libvirt could get into this situation due to
Do you mean to allow the scene: * The checkpoint( thought invalid by old libvirt) produced by older libvirt can be thought valid if restored by the patched newer libvirt? But it will also allow a typo xml. * Another scene may be live migration between old libvirt and newer libvirt (pls correct me if err) If so, I think these scene should be documented or commented here or in the commit msg explicitly, otherwise this piece of code may confuse many readers, because I don't think cur_balloon can exceed max_balloon again after patched (so if exceed must be typo xml).
+ * rounding; if the discrepancy is less than 1MiB, we silently + * round down, otherwise we flag the issue. */ + if (VIR_DIV_UP(def->mem.cur_balloon, 1024) > + VIR_DIV_UP(def->mem.max_balloon, 1024)) { + virDomainReportError(VIR_ERR_XML_ERROR, + _("current memory '%lluk' exceeds " + "maximum '%lluk'"), + def->mem.cur_balloon, def->mem.max_balloon); + goto error; + } else { + VIR_DEBUG("Truncating current %lluk to maximum %lluk", + def->mem.cur_balloon, def->mem.max_balloon); + def->mem.cur_balloon = def->mem.max_balloon; + } } else if (def->mem.cur_balloon == 0) { def->mem.cur_balloon = def->mem.max_balloon; } diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c index 7093e1d..6d66587 100644 --- a/src/qemu/qemu_monitor_json.c +++ b/src/qemu/qemu_monitor_json.c @@ -2022,7 +2022,7 @@ int qemuMonitorJSONSetBalloon(qemuMonitorPtr mon, { int ret; virJSONValuePtr cmd = qemuMonitorJSONMakeCommand("balloon", - "U:value", ((unsigned long long)newmem)*1024, + "U:value", newmem*1024ULL, NULL); virJSONValuePtr reply = NULL; if (!cmd) -- 1.7.1
-- Zhou Peng