Merge pull request #32608 from darrenstahlmsft/WindowsNanoCPUs

Windows: Fix scaling of NanoCPUs (--cpus) on Hyper-V containers

daemon/daemon_windows.go

@@ -146,6 +146,17 @@ func verifyContainerResources(resources *containertypes.Resources, isHyperv bool
 		return warnings, fmt.Errorf("range of CPUs is from 0.01 to %d.00, as there are only %d CPUs available", sysinfo.NumCPU(), sysinfo.NumCPU())
 	}
 
+	osv := system.GetOSVersion()
+	if resources.NanoCPUs > 0 && isHyperv && osv.Build < 16175 {
+		leftoverNanoCPUs := resources.NanoCPUs % 1e9
+		if leftoverNanoCPUs != 0 && resources.NanoCPUs > 1e9 {
+			resources.NanoCPUs = ((resources.NanoCPUs + 1e9/2) / 1e9) * 1e9
+			warningString := fmt.Sprintf("Your current OS version does not support Hyper-V containers with NanoCPUs greater than 1000000000 but not divisible by 1000000000. NanoCPUs rounded to %d", resources.NanoCPUs)
+			warnings = append(warnings, warningString)
+			logrus.Warn(warningString)
+		}
+	}
+
 	if len(resources.BlkioDeviceReadBps) > 0 {
 		return warnings, fmt.Errorf("invalid option: Windows does not support BlkioDeviceReadBps")
 	}

daemon/oci_windows.go

@@ -81,10 +81,19 @@ func (daemon *Daemon) createSpec(c *container.Container) (*specs.Spec, error) {
 	// @darrenstahlmsft implement these resources
 	cpuShares := uint16(c.HostConfig.CPUShares)
 	cpuPercent := uint8(c.HostConfig.CPUPercent)
+	cpuCount := uint64(c.HostConfig.CPUCount)
 	if c.HostConfig.NanoCPUs > 0 {
-		cpuPercent = uint8(c.HostConfig.NanoCPUs * 100 / int64(sysinfo.NumCPU()) / 1e9)
+		if isHyperV {
+			cpuCount = uint64(c.HostConfig.NanoCPUs / 1e9)
+			leftoverNanoCPUs := c.HostConfig.NanoCPUs % 1e9
+			if leftoverNanoCPUs != 0 {
+				cpuCount++
+				cpuPercent = uint8(c.HostConfig.NanoCPUs * 100 / int64(cpuCount) / 1e9)
+			}
+		} else {
+			cpuPercent = uint8(c.HostConfig.NanoCPUs * 100 / int64(sysinfo.NumCPU()) / 1e9)
+		}
 	}
-	cpuCount := uint64(c.HostConfig.CPUCount)
 	memoryLimit := uint64(c.HostConfig.Memory)
 	s.Windows.Resources = &specs.WindowsResources{
 		CPU: &specs.WindowsCPUResources{