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Fix MMIO overhead calculation for unreserved adapters #5413

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Merged
rene merged 1 commit into from
Nov 20, 2025
Merged

Fix MMIO overhead calculation for unreserved adapters #5413

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31 changes: 16 additions & 15 deletions pkg/pillar/hypervisor/kvm.go
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Original file line number Diff line number Diff line change
Expand Up @@ -754,32 +754,32 @@ func mmioVMMOverhead(domainName string, aa *types.AssignableAdapters, domainAdap
var mmioSize uint64

for _, adapter := range domainAdapterList {
logrus.Debugf("processing adapter %d %s\n", adapter.Type, adapter.Name)
logrus.Debugf("mmioVMMOverhead: processing adapter %d %s for overhead estimation (not reserving) for domain %s (UUID: %s)",
adapter.Type, adapter.Name, domainName, domainUUID)
aaList := aa.LookupIoBundleAny(adapter.Name)
// We reserved it in handleCreate so nobody could have stolen it
if len(aaList) == 0 {
return 0, logError("IoBundle disappeared %d %s for %s\n",
adapter.Type, adapter.Name, domainName)
return 0, logError("mmioVMMOverhead: IoBundle not found %d %s for domain %s (UUID: %s)\n",
adapter.Type, adapter.Name, domainName, domainUUID)
}
for _, ib := range aaList {
if ib == nil {
continue
}
if ib.UsedByUUID != domainUUID {
return 0, logError("IoBundle not ours %s: %d %s for %s\n",
ib.UsedByUUID, adapter.Type, adapter.Name,
domainName)
}
// For memory overhead calculation, we process all matching adapters
// regardless of UsedByUUID status, since this is for estimation only,
// not actual reservation.
if ib.PciLong != "" && ib.UsbAddr == "" {
logrus.Infof("Adding PCI device <%s>\n", ib.PciLong)
logrus.Infof("mmioVMMOverhead: counting MMIO for PCI device <%s> (not reserving) for domain %s (UUID: %s)",
ib.PciLong, domainName, domainUUID)
tap := pciDevice{ioBundle: *ib}
pciAssignments = addNoDuplicatePCI(pciAssignments, tap)
}
}
}

for _, dev := range pciAssignments {
logrus.Infof("PCI device %s %d\n", dev.ioBundle.PciLong, dev.ioBundle.Type)
logrus.Infof("mmioVMMOverhead: reading MMIO size for PCI device %s %d for domain %s",
dev.ioBundle.PciLong, dev.ioBundle.Type, domainName)
// read the size of the PCI device aperture. Only GPU/VGA devices for now
if dev.ioBundle.Type != types.IoOther && dev.ioBundle.Type != types.IoHDMI {
continue
Expand All @@ -788,20 +788,20 @@ func mmioVMMOverhead(domainName string, aa *types.AssignableAdapters, domainAdap
isBridge, err := dev.isBridge()
if err != nil {
// do not treat as fatal error
logrus.Warnf("Can't read PCI device class, treat as bridge %s: %v\n",
logrus.Warnf("mmioVMMOverhead: can't read PCI device class, treating as bridge %s: %v",
dev.ioBundle.PciLong, err)
isBridge = true
}

if isBridge {
logrus.Infof("Skipping bridge %s\n", dev.ioBundle.PciLong)
logrus.Infof("mmioVMMOverhead: skipping PCI bridge %s\n", dev.ioBundle.PciLong)
continue
}

// read all resources of the PCI device
resources, err := dev.readResources(sysfsPciDevices)
if err != nil {
return 0, logError("Can't read PCI device resources %s: %v\n",
return 0, logError("mmioVMMOverhead: can't read PCI device resources %s: %v\n",
dev.ioBundle.PciLong, err)
}

Expand All @@ -816,7 +816,8 @@ func mmioVMMOverhead(domainName string, aa *types.AssignableAdapters, domainAdap
// 1% of the total MMIO size in bytes
mmioOverhead := int64(mmioSize) / 100

logrus.Infof("MMIO size: %d / overhead: %d for %s", mmioSize, mmioOverhead, domainName)
logrus.Infof("mmioVMMOverhead: calculated MMIO overhead for domain %s (UUID: %s): total MMIO %d bytes, overhead %d bytes",
domainName, domainUUID, mmioSize, mmioOverhead)

return int64(mmioOverhead), nil
}
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