From 3ac159eae0eaa3a2b41b968a1a15073a23ce7217 Mon Sep 17 00:00:00 2001
From: Zexi Li <zexi.li@icloud.com>
Date: Tue, 6 Aug 2024 10:15:42 +0800
Subject: [PATCH] feat(region): select isolated_device by most unused
 device_path count (#20964)

---
 pkg/compute/models/isolated_devices.go | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/pkg/compute/models/isolated_devices.go b/pkg/compute/models/isolated_devices.go
index 500113d0a5..64cc742069 100644
--- a/pkg/compute/models/isolated_devices.go
+++ b/pkg/compute/models/isolated_devices.go
@@ -614,7 +614,30 @@ func (manager *SIsolatedDeviceManager) attachHostDeviceToGuestByModel(ctx contex
 	if err != nil || len(devs) == 0 {
 		return fmt.Errorf("Can't found model %s on host %s", devConfig.Model, host.Id)
 	}
-	selectedDev := devs[0]
+	// 1. group devices by device_path
+	groupDevs := make(map[string][]SIsolatedDevice, 0)
+	for i := range devs {
+		dev := devs[i]
+		devPath := dev.DevicePath
+		devs, ok := groupDevs[devPath]
+		if !ok {
+			devs = []SIsolatedDevice{dev}
+		} else {
+			devs = append(devs, dev)
+		}
+		groupDevs[devPath] = devs
+	}
+	// 2. select device by most unused count
+	var mostUnusedDevPath string
+	mostUnusedCount := 0
+	for devPath := range groupDevs {
+		devs := groupDevs[devPath]
+		if len(devs) > mostUnusedCount {
+			mostUnusedDevPath = devPath
+			mostUnusedCount = len(devs)
+		}
+	}
+	selectedDev := groupDevs[mostUnusedDevPath][0]
 	return guest.attachIsolatedDevice(ctx, userCred, &selectedDev, devConfig.NetworkIndex, devConfig.DiskIndex)
 }