On 05/24/2017 05:06 PM, Daniel P. Berrange wrote: > On Wed, May 24, 2017 at 04:45:57PM +0200, Michal Privoznik wrote: >> https://bugzilla.redhat.com/show_bug.cgi?id=1450349 >> >> Problem is, qemu fails to load guest memory image if these >> attribute change on migration/restore from an image. > > [snip] > >> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c >> index 35fd79de8..c1ff8ca8a 100644 >> --- a/src/qemu/qemu_domain.c >> +++ b/src/qemu/qemu_domain.c >> @@ -5797,6 +5797,46 @@ qemuDomainUpdateMemoryDeviceInfo(virQEMUDriverPtr driver, >> } >> >> >> +static bool >> +qemuDomainABIStabilityCheck(const virDomainDef *src, >> + const virDomainDef *dst) >> +{ >> + if (src->mem.source != dst->mem.source) { >> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, >> + _("Target memoryBacking source '%s' doesn't " >> + "match source memoryBacking source'%s'"), >> + virDomainMemorySourceTypeToString(dst->mem.source), >> + virDomainMemorySourceTypeToString(src->mem.source)); >> + return false; >> + } >> + >> + if (src->mem.access != dst->mem.access) { >> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, >> + _("Target memoryBacking access '%s' doesn't " >> + "match access memoryBacking access'%s'"), >> + virDomainMemoryAccessTypeToString(dst->mem.access), >> + virDomainMemoryAccessTypeToString(src->mem.access)); >> + return false; >> + } >> + >> + if (src->mem.allocation != dst->mem.allocation) { >> + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, >> + _("Target memoryBacking allocation '%s' doesn't " >> + "match allocation memoryBacking allocation'%s'"), >> + virDomainMemoryAllocationTypeToString(dst->mem.allocation), >> + virDomainMemoryAllocationTypeToString(src->mem.allocation)); >> + return false; >> + } > > > Do we really need to blacklist all of these changes. I can understand that > changing the memory source would affect migration ABI, as it causes us to > use the memory backend command line config differently. > > Assuming that matches though, I'm sceptical that changing 'access' or > 'allocation' affects ABI. Yep, you're right. Only memory source change causes trouble. Other twos can be changed without any harm. v2 on its way. Michal -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list
