Fix NVIDIA GPU serial number format extraction

Extract decimal serial numbers from devname parameters (e.g., "SXM5_SN_1653925027099")
instead of hex PCIe Device Serial Numbers. This provides the correct GPU serial
numbers as they appear in NVIDIA diagnostics tooling.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

internal/parser/vendors/nvidia/inventory_log.go

@@ -10,22 +10,13 @@ import (
 )
 
 var (
-	// Regex to extract GPU serial numbers from lspci output
-	// Example: "	Capabilities: [2f0 v1] Device Serial Number 14-17-dc-65-77-2d-b0-48"
-	gpuSerialRegex = regexp.MustCompile(`Device Serial Number\s+([\da-fA-F-]+)`)
-
-	// Regex to extract PCI BDF from lspci header
-	// Example: "2a:00.0 3D controller: NVIDIA Corporation Device 2335 (rev a1)"
-	// Note: lspci format is bus:device.function (e.g., "2a:00.0")
-	pciBDFRegex = regexp.MustCompile(`^([0-9a-fA-F]{2,4}:[0-9a-fA-F]{2}\.[0-9])\s+3D controller.*NVIDIA`)
-
 	// Regex to extract devname mappings from fieldiag command line
 	// Example: "devname=0000:ba:00.0,SXM5_SN_1653925027099"
 	devnameRegex = regexp.MustCompile(`devname=([\da-fA-F:\.]+),(\w+)`)
 )
 
 // ParseInventoryLog parses inventory/output.log to extract GPU serial numbers
-// from lspci output and map them to slots
+// from fieldiag devname parameters (e.g., "SXM5_SN_1653925027099")
 func ParseInventoryLog(content []byte, result *models.AnalysisResult) error {
 	if result.Hardware == nil || len(result.Hardware.GPUs) == 0 {
 		// No GPUs to update
@@ -34,8 +25,9 @@ func ParseInventoryLog(content []byte, result *models.AnalysisResult) error {
 
 	scanner := bufio.NewScanner(strings.NewReader(string(content)))
 
-	// First pass: build mapping of PCI BDF -> Slot name from fieldiag command line
+	// First pass: build mapping of PCI BDF -> Slot name and serial number from fieldiag command line
 	pciToSlot := make(map[string]string)
+	pciToSerial := make(map[string]string)
 	for scanner.Scan() {
 		line := scanner.Text()
 		// Look for fieldiag command with devname parameters
@@ -45,8 +37,7 @@ func ParseInventoryLog(content []byte, result *models.AnalysisResult) error {
 				if len(match) == 3 {
 					pciBDF := match[1]
 					slotName := match[2]
-					// Extract slot number from name like "SXM5_SN_1653925027099"
-					// We want to map to slot like "GPUSXM5"
+					// Extract slot number and serial from name like "SXM5_SN_1653925027099"
 					if strings.HasPrefix(slotName, "SXM") {
 						parts := strings.Split(slotName, "_")
 						if len(parts) >= 1 {
@@ -54,81 +45,39 @@ func ParseInventoryLog(content []byte, result *models.AnalysisResult) error {
 							slot := "GPU" + parts[0]
 							pciToSlot[pciBDF] = slot
 						}
+						// Extract serial number from "SXM5_SN_1653925027099"
+						if len(parts) == 3 && parts[1] == "SN" {
+							serial := parts[2]
+							pciToSerial[pciBDF] = serial
+						}
 					}
 				}
 			}
 		}
 	}
 
-	// Second pass: extract GPU serial numbers from lspci output
-	scanner = bufio.NewScanner(strings.NewReader(string(content)))
-	var currentPCIBDF string
-	var currentSlot string
-
-	for scanner.Scan() {
-		line := scanner.Text()
-
-		// Check if this is a new GPU device header
-		if match := pciBDFRegex.FindStringSubmatch(line); len(match) > 1 {
-			currentPCIBDF = match[1]
-			// Normalize BDF format - lspci uses short format (bus:device.function)
-			// but fieldiag uses full format (domain:bus:device.function)
-			// Convert "2a:00.0" to "0000:2a:00.0"
-			normalizedBDF := currentPCIBDF
-			if len(strings.Split(currentPCIBDF, ":")) == 2 {
-				// Short format without domain, add 0000:
-				normalizedBDF = "0000:" + currentPCIBDF
-			}
-
-			// Map to slot name if we have it
-			if slot, ok := pciToSlot[normalizedBDF]; ok {
-				currentSlot = slot
-			} else if slot, ok := pciToSlot[currentPCIBDF]; ok {
-				currentSlot = slot
-			} else {
-				currentSlot = ""
-			}
-			continue
-		}
-
-		// Look for Device Serial Number in capabilities
-		if match := gpuSerialRegex.FindStringSubmatch(line); len(match) > 1 && currentSlot != "" {
-			serialNumber := match[1]
-			// Format: 14-17-dc-65-77-2d-b0-48
-			// Convert to more readable format: 48:b0:2d:77:65:dc:17:14 (reversed)
-			serialFormatted := formatGPUSerial(serialNumber)
-
-			// Find the GPU in our results and update its serial number
-			for i := range result.Hardware.GPUs {
-				if result.Hardware.GPUs[i].Slot == currentSlot {
-					result.Hardware.GPUs[i].SerialNumber = serialFormatted
+	// Second pass: assign serial numbers to GPUs based on slot mapping
+	for i := range result.Hardware.GPUs {
+		slot := result.Hardware.GPUs[i].Slot
+		// Find the PCI BDF for this slot
+		var foundSerial string
+		for pciBDF, mappedSlot := range pciToSlot {
+			if mappedSlot == slot {
+				// Found matching slot, get serial number
+				if serial, ok := pciToSerial[pciBDF]; ok {
+					foundSerial = serial
 					break
 				}
 			}
 		}
+		if foundSerial != "" {
+			result.Hardware.GPUs[i].SerialNumber = foundSerial
+		}
 	}
 
 	return scanner.Err()
 }
 
-// formatGPUSerial formats GPU serial number from PCIe format to human-readable
-// Input: "14-17-dc-65-77-2d-b0-48" (little-endian from PCIe)
-// Output: "48:b0:2d:77:65:dc:17:14" (reversed to match GPU label)
-func formatGPUSerial(serial string) string {
-	parts := strings.Split(serial, "-")
-	if len(parts) != 8 {
-		return serial // Return as-is if unexpected format
-	}
-
-	// Reverse the bytes (PCIe reports in little-endian)
-	reversed := make([]string, len(parts))
-	for i := range parts {
-		reversed[len(parts)-1-i] = strings.ToUpper(parts[i])
-	}
-
-	return strings.Join(reversed, ":")
-}
-
 // findInventoryOutputLog finds the inventory/output.log file
 func findInventoryOutputLog(files []parser.ExtractedFile) *parser.ExtractedFile {
 	for _, f := range files {