From 7d7b6643b23cef0204bdc58a9ef519baa3a535f2 Mon Sep 17 00:00:00 2001
From: vishesh92 <vishesh92@gmail.com>
Date: Wed, 8 Apr 2026 14:15:01 +0530
Subject: [PATCH 1/6] Fix domain parsing for GPU

---
 .../kvm/resource/LibvirtGpuDef.java           |  16 +-
 .../kvm/resource/LibvirtGpuDefTest.java       | 104 ++++++++++
 scripts/vm/hypervisor/kvm/gpudiscovery.sh     | 192 ++++++++++++++----
 3 files changed, 264 insertions(+), 48 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
index 08086859fb70..77ee9b0af31f 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
@@ -79,7 +79,9 @@ private void generatePciXml(StringBuilder gpuBuilder) {
         gpuBuilder.append("  <driver name='vfio'/>\n");
         gpuBuilder.append("  <source>\n");
 
-        // Parse the bus address (e.g., 00:02.0) into domain, bus, slot, function
+        // Parse the bus address into domain, bus, slot, function. Two input formats are accepted:
+        //   - "dddd:bb:ss.f"  full PCI address with domain (e.g. 0000:00:02.0)
+        //   - "bb:ss.f"       legacy short BDF; domain defaults to 0000
         String domain = "0x0000";
         String bus = "0x00";
         String slot = "0x00";
@@ -87,9 +89,17 @@ private void generatePciXml(StringBuilder gpuBuilder) {
 
         if (busAddress != null && !busAddress.isEmpty()) {
             String[] parts = busAddress.split(":");
-            if (parts.length > 1) {
+            String slotFunction = null;
+            if (parts.length == 3) {
+                domain = "0x" + parts[0];
+                bus = "0x" + parts[1];
+                slotFunction = parts[2];
+            } else if (parts.length == 2) {
                 bus = "0x" + parts[0];
-                String[] slotFunctionParts = parts[1].split("\\.");
+                slotFunction = parts[1];
+            }
+            if (slotFunction != null) {
+                String[] slotFunctionParts = slotFunction.split("\\.");
                 if (slotFunctionParts.length > 0) {
                     slot = "0x" + slotFunctionParts[0];
                     if (slotFunctionParts.length > 1) {
diff --git a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
index 0060e1d7ed4d..6b8eac8e2231 100644
--- a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
@@ -115,6 +115,110 @@ public void testGpuDef_withComplexPciAddress() {
         assertTrue(gpuXml.contains("</hostdev>"));
     }
 
+    @Test
+    public void testGpuDef_withFullPciAddressDomainZero() {
+        LibvirtGpuDef gpuDef = new LibvirtGpuDef();
+        VgpuTypesInfo pciGpuInfo = new VgpuTypesInfo(
+                GpuDevice.DeviceType.PCI,
+                "passthrough",
+                "passthrough",
+                "0000:00:02.0",
+                "10de",
+                "NVIDIA Corporation",
+                "1b38",
+                "Tesla T4"
+        );
+        gpuDef.defGpu(pciGpuInfo);
+
+        String gpuXml = gpuDef.toString();
+
+        assertTrue(gpuXml.contains("<address domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>"));
+    }
+
+    @Test
+    public void testGpuDef_withFullPciAddressNonZeroDomain() {
+        LibvirtGpuDef gpuDef = new LibvirtGpuDef();
+        VgpuTypesInfo pciGpuInfo = new VgpuTypesInfo(
+                GpuDevice.DeviceType.PCI,
+                "passthrough",
+                "passthrough",
+                "0001:65:00.0",
+                "10de",
+                "NVIDIA Corporation",
+                "1b38",
+                "Tesla T4"
+        );
+        gpuDef.defGpu(pciGpuInfo);
+
+        String gpuXml = gpuDef.toString();
+
+        assertTrue(gpuXml.contains("<address domain='0x0001' bus='0x65' slot='0x00' function='0x0'/>"));
+    }
+
+    @Test
+    public void testGpuDef_withFullPciAddressWideDomain() {
+        LibvirtGpuDef gpuDef = new LibvirtGpuDef();
+        VgpuTypesInfo pciGpuInfo = new VgpuTypesInfo(
+                GpuDevice.DeviceType.PCI,
+                "passthrough",
+                "passthrough",
+                "10000:af:00.1",
+                "10de",
+                "NVIDIA Corporation",
+                "1b38",
+                "Tesla T4"
+        );
+        gpuDef.defGpu(pciGpuInfo);
+
+        String gpuXml = gpuDef.toString();
+
+        assertTrue(gpuXml.contains("<address domain='0x10000' bus='0xaf' slot='0x00' function='0x1'/>"));
+    }
+
+    @Test
+    public void testGpuDef_withFullPciAddressVfNonZeroDomain() {
+        LibvirtGpuDef gpuDef = new LibvirtGpuDef();
+        VgpuTypesInfo vfGpuInfo = new VgpuTypesInfo(
+                GpuDevice.DeviceType.PCI,
+                "VF-Profile",
+                "VF-Profile",
+                "0002:81:00.3",
+                "10de",
+                "NVIDIA Corporation",
+                "1eb8",
+                "Tesla T4"
+        );
+        gpuDef.defGpu(vfGpuInfo);
+
+        String gpuXml = gpuDef.toString();
+
+        // Non-passthrough NVIDIA VFs should be unmanaged
+        assertTrue(gpuXml.contains("<hostdev mode='subsystem' type='pci' managed='no' display='off'>"));
+        assertTrue(gpuXml.contains("<address domain='0x0002' bus='0x81' slot='0x00' function='0x3'/>"));
+    }
+
+    @Test
+    public void testGpuDef_withLegacyShortBdfDefaultsDomainToZero() {
+        // Backward compatibility: short BDF with no domain segment must still
+        // produce a valid libvirt address with domain 0x0000.
+        LibvirtGpuDef gpuDef = new LibvirtGpuDef();
+        VgpuTypesInfo pciGpuInfo = new VgpuTypesInfo(
+                GpuDevice.DeviceType.PCI,
+                "passthrough",
+                "passthrough",
+                "af:00.0",
+                "10de",
+                "NVIDIA Corporation",
+                "1b38",
+                "Tesla T4"
+        );
+        gpuDef.defGpu(pciGpuInfo);
+
+        String gpuXml = gpuDef.toString();
+
+        assertTrue(gpuXml.contains("<address domain='0x0000' bus='0xaf' slot='0x00' function='0x0'/>"));
+    }
+
     @Test
     public void testGpuDef_withNullDeviceType() {
         LibvirtGpuDef gpuDef = new LibvirtGpuDef();
diff --git a/scripts/vm/hypervisor/kvm/gpudiscovery.sh b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
index bf6892c898db..e7c40c8810ca 100755
--- a/scripts/vm/hypervisor/kvm/gpudiscovery.sh
+++ b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
@@ -357,7 +357,33 @@
 
 #   	"vgpu_instances":[],
 #   	"vf_instances":[]
-# 	  }
+# 	  },
+# 	  {
+#       "pci_address": "0001:65:00.0",
+#       "vendor_id": "10de",
+#       "device_id": "20B0",
+#       "vendor": "NVIDIA Corporation",
+#       "device": "A100-SXM4-40GB",
+#       "driver": "nvidia",
+#       "pci_class": "3D controller",
+#       "iommu_group": "20",
+#       "sriov_totalvfs": 0,
+#       "sriov_numvfs": 0,
+#
+#       "full_passthrough": {
+#         "enabled": true,
+#         "libvirt_address": {
+#           "domain": "0x0001",
+#           "bus": "0x65",
+#           "slot": "0x00",
+#           "function": "0x0"
+#         },
+#         "used_by_vm": "ml-train"
+#       },
+#
+#       "vgpu_instances": [],
+#       "vf_instances": []
+#     }
 #   ]
 # }
 #
@@ -416,9 +442,22 @@ parse_nvidia_vgpu_profiles() {
 			store_profile_data
 
 			gpu_address="${BASH_REMATCH[1]}"
-			# Convert from format like 00000000:AF:00.0 to AF:00.0 and normalize to lowercase
-			if [[ $gpu_address =~ [0-9A-Fa-f]+:([0-9A-Fa-f]+:[0-9A-Fa-f]+\.[0-9A-Fa-f]+) ]]; then
-				gpu_address="${BASH_REMATCH[1],,}"
+			# nvidia-smi reports addresses in the form "00000000:AF:00.0"
+			# (8-digit domain). Reformat to the canonical 4-digit
+			# "dddd:bb:ss.f" lowercase form so cache keys line up with the
+			# normalize_pci_address output used at lookup time. Short
+			# addresses ("AF:00.0") are widened by prepending domain 0.
+			if [[ $gpu_address =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
+				gpu_address=$(printf "%04x:%s:%s.%s" \
+					"0x${BASH_REMATCH[1]}" \
+					"${BASH_REMATCH[2],,}" \
+					"${BASH_REMATCH[3],,}" \
+					"${BASH_REMATCH[4],,}")
+			elif [[ $gpu_address =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
+				gpu_address=$(printf "0000:%s:%s.%s" \
+					"${BASH_REMATCH[1],,}" \
+					"${BASH_REMATCH[2],,}" \
+					"${BASH_REMATCH[3],,}")
 			else
 				gpu_address="${gpu_address,,}"
 			fi
@@ -506,10 +545,52 @@ get_nvidia_profile_info() {
 	fi
 }
 
-# Get nodedev name for a PCI address (e.g. "00:02.0" -> "pci_0000_00_02_0")
-get_nodedev_name() {
+# Parse a PCI address and assign the libvirt-formatted DOMAIN/BUS/SLOT/FUNC
+# values into the caller's scope. Accepts both full ("0000:00:02.0") and short
+# ("00:02.0") formats; short addresses are assumed to be in PCI domain 0.
+#
+# IMPORTANT: bash uses dynamic scoping, so callers that don't want these four
+# values to leak into the global scope MUST declare them `local` before
+# invoking this function, e.g.:
+#     local DOMAIN BUS SLOT FUNC
+#     parse_pci_address "$addr"
+parse_pci_address() {
+	local addr="$1"
+	if [[ $addr =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
+		DOMAIN="0x${BASH_REMATCH[1]}"
+		BUS="0x${BASH_REMATCH[2]}"
+		SLOT="0x${BASH_REMATCH[3]}"
+		FUNC="0x${BASH_REMATCH[4]}"
+	elif [[ $addr =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
+		DOMAIN="0x0000"
+		BUS="0x${BASH_REMATCH[1]}"
+		SLOT="0x${BASH_REMATCH[2]}"
+		FUNC="0x${BASH_REMATCH[3]}"
+	else
+		DOMAIN="0x0000"
+		BUS="0x00"
+		SLOT="0x00"
+		FUNC="0x0"
+	fi
+}
+
+# Normalize a PCI address to its full domain-qualified form ("dddd:bb:ss.f").
+# Short addresses are widened by prepending domain "0000".
+normalize_pci_address() {
 	local addr="$1"
-	echo "pci_$(echo "$addr" | sed 's/[:.]/\_/g' | sed 's/^/0000_/')"
+	if [[ $addr =~ ^[0-9A-Fa-f]+:[0-9A-Fa-f]+:[0-9A-Fa-f]+\.[0-9A-Fa-f]+$ ]]; then
+		echo "$addr"
+	else
+		echo "0000:$addr"
+	fi
+}
+
+# Get nodedev name for a PCI address (e.g. "0000:00:02.0" -> "pci_0000_00_02_0").
+# Short addresses are widened to domain 0 first.
+get_nodedev_name() {
+	local addr
+	addr=$(normalize_pci_address "$1")
+	echo "pci_$(echo "$addr" | sed 's/[:.]/\_/g')"
 }
 
 # Get cached nodedev XML for a PCI address
@@ -572,9 +653,12 @@ get_numa_node() {
 	echo "${node:--1}"
 }
 
-# Given a PCI address, return its PCI root (the top‐level bridge ID, e.g. "0000:00:03")
+# Given a PCI address, return its PCI root (the top‐level bridge ID, e.g.
+# "0000:00:03.0"). Both full ("0000:00:02.0") and short ("00:02.0") inputs are
+# accepted; output is always domain-qualified.
 get_pci_root() {
-	local addr="$1"
+	local addr
+	addr=$(normalize_pci_address "$1")
 	local xml
 	xml=$(get_nodedev_xml "$addr")
 
@@ -583,21 +667,23 @@ get_pci_root() {
 		local parent
 		parent=$(echo "$xml" | xmlstarlet sel -t -v "/device/parent" 2>/dev/null || true)
 		if [[ -n "$parent" ]]; then
-			# If parent is a PCI device, recursively find its root
-			if [[ $parent =~ ^pci_0000_([0-9A-Fa-f]{2})_([0-9A-Fa-f]{2})_([0-9A-Fa-f])$ ]]; then
-				local parent_addr="${BASH_REMATCH[1]}:${BASH_REMATCH[2]}.${BASH_REMATCH[3]}"
+			# If parent is a PCI device, recursively find its root.
+			# libvirt nodedev names look like pci_<domain>_<bus>_<slot>_<func>
+			# where <domain> is one or more hex digits (typically 4).
+			if [[ $parent =~ ^pci_([0-9A-Fa-f]+)_([0-9A-Fa-f]{2})_([0-9A-Fa-f]{2})_([0-9A-Fa-f])$ ]]; then
+				local parent_addr="${BASH_REMATCH[1]}:${BASH_REMATCH[2]}:${BASH_REMATCH[3]}.${BASH_REMATCH[4]}"
 				get_pci_root "$parent_addr"
 				return
 			else
-				# Parent is not PCI device, so current device is the root
-				echo "0000:$addr"
+				# Parent is not a PCI device, so current device is the root
+				echo "$addr"
 				return
 			fi
 		fi
 	fi
 
 	# fallback
-	echo "0000:$addr"
+	echo "$addr"
 }
 
 # Build VM → hostdev maps:
@@ -613,16 +699,21 @@ for VM in "${VMS[@]}"; do
 		continue
 	fi
 
-	# -- PCI hostdevs: use xmlstarlet to extract BDF for all PCI host devices --
-	while read -r bus slot func; do
+	# -- PCI hostdevs: use xmlstarlet to extract the full domain:bus:slot.func
+	# for all PCI host devices. libvirt's <address> element may omit the domain
+	# attribute, in which case we default to 0.
+	while read -r dom bus slot func; do
 		[[ -n "$bus" && -n "$slot" && -n "$func" ]] || continue
-		# Format to match lspci output (e.g., 01:00.0) by padding with zeros
+		[[ -n "$dom" ]] || dom="0"
+		# Format to match lspci -D output (e.g., 0000:01:00.0) by padding with zeros
+		dom_fmt=$(printf "%04x" "0x$dom")
 		bus_fmt=$(printf "%02x" "0x$bus")
 		slot_fmt=$(printf "%02x" "0x$slot")
 		func_fmt=$(printf "%x" "0x$func")
-		BDF="$bus_fmt:$slot_fmt.$func_fmt"
+		BDF="${dom_fmt}:${bus_fmt}:${slot_fmt}.${func_fmt}"
 		pci_to_vm["$BDF"]="$VM"
 	done < <(echo "$xml" | xmlstarlet sel -T -t -m "//hostdev[@type='pci']/source/address" \
+		-v "substring-after(@domain, '0x')" -o " " \
 		-v "substring-after(@bus, '0x')" -o " " \
 		-v "substring-after(@slot, '0x')" -o " " \
 		-v "substring-after(@function, '0x')" -n 2>/dev/null || true)
@@ -677,7 +768,8 @@ parse_and_add_gpu_properties() {
 # Appends JSON strings for each found mdev instance to the global 'vlist' array.
 # Arguments:
 #   $1: mdev_base_path (e.g., /sys/bus/pci/devices/.../mdev_supported_types)
-#   $2: bdf (e.g., 01:00.0)
+#   $2: bdf — short "bb:ss.f" (e.g. 01:00.0) or full
+#       "dddd:bb:ss.f" (e.g. 0001:65:00.0) for non-zero PCI domains
 process_mdev_instances() {
 	local mdev_base_path="$1"
 	local bdf="$2"
@@ -705,10 +797,8 @@ process_mdev_instances() {
 				local MDEV_UUID
 				MDEV_UUID=$(basename "$UDIR")
 
-				local DOMAIN="0x0000"
-				local BUS="0x${bdf:0:2}"
-				local SLOT="0x${bdf:3:2}"
-				local FUNC="0x${bdf:6:1}"
+				local DOMAIN BUS SLOT FUNC
+				parse_pci_address "$bdf"
 
 				local raw
 				raw="${mdev_to_vm[$MDEV_UUID]:-}"
@@ -727,6 +817,10 @@ process_mdev_instances() {
 # Parse nvidia-smi vgpu profiles once at the beginning
 parse_nvidia_vgpu_profiles
 
+# `lspci -nnm` keeps the existing output format for devices in PCI domain 0
+# (short "bb:ss.f" form) and includes the domain prefix only for devices on
+# non-zero PCI segments (multi-IIO servers, some ARM systems). The helpers
+# below (parse_pci_address, normalize_pci_address) accept both formats.
 mapfile -t LINES < <(lspci -nnm)
 
 echo '{ "gpus": ['
@@ -743,8 +837,13 @@ for LINE in "${LINES[@]}"; do
 		continue
 	fi
 
+	# sysfs paths always require the full domain-qualified form. PCI_ADDR may
+	# be short ("00:02.0") for domain 0 or full ("0001:65:00.0") otherwise, so
+	# we derive a separate SYSFS_ADDR just for filesystem lookups.
+	SYSFS_ADDR=$(normalize_pci_address "$PCI_ADDR")
+
 	# If this is a VF, skip it. It will be processed under its PF.
-	if [[ -e "/sys/bus/pci/devices/0000:$PCI_ADDR/physfn" ]]; then
+	if [[ -e "/sys/bus/pci/devices/$SYSFS_ADDR/physfn" ]]; then
 		continue
 	fi
 
@@ -761,7 +860,7 @@ for LINE in "${LINES[@]}"; do
 	DEVICE_ID=$(sed -E 's/.*\[([0-9A-Fa-f]{4})\]$/\1/' <<<"$DEVICE_FIELD")
 
 	# Kernel driver
-	DRV_PATH="/sys/bus/pci/devices/0000:$PCI_ADDR/driver"
+	DRV_PATH="/sys/bus/pci/devices/$SYSFS_ADDR/driver"
 	if [[ -L $DRV_PATH ]]; then
 		DRIVER=$(basename "$(readlink "$DRV_PATH")")
 	else
@@ -781,7 +880,7 @@ for LINE in "${LINES[@]}"; do
 	read -r TOTALVFS NUMVFS < <(get_sriov_counts "$PCI_ADDR")
 
 	# Get Physical GPU properties from its own description file, if available
-	PF_DESC_PATH="/sys/bus/pci/devices/0000:$PCI_ADDR/description"
+	PF_DESC_PATH="/sys/bus/pci/devices/$SYSFS_ADDR/description"
 	parse_and_add_gpu_properties "$PF_DESC_PATH"
 	# Save physical function's properties before they are overwritten by vGPU/VF processing
 	PF_MAX_INSTANCES=$MAX_INSTANCES
@@ -791,25 +890,27 @@ for LINE in "${LINES[@]}"; do
 	PF_MAX_RESOLUTION_Y=$MAX_RESOLUTION_Y
 
 	# === full_passthrough usage ===
-	raw="${pci_to_vm[$PCI_ADDR]:-}"
+	# pci_to_vm is keyed by the full domain-qualified form, so normalize the
+	# lspci-style PCI_ADDR (which may be short for domain 0) before lookup.
+	raw="${pci_to_vm[$(normalize_pci_address "$PCI_ADDR")]:-}"
 	FULL_USED_JSON=$(to_json_vm "$raw")
 
 	# === vGPU (MDEV) instances ===
 	VGPU_ARRAY="[]"
 	declare -a vlist=()
 	# Process mdev on the Physical Function
-	MDEV_BASE="/sys/bus/pci/devices/0000:$PCI_ADDR/mdev_supported_types"
+	MDEV_BASE="/sys/bus/pci/devices/$SYSFS_ADDR/mdev_supported_types"
 	process_mdev_instances "$MDEV_BASE" "$PCI_ADDR"
 
 	# === VF instances (SR-IOV / MIG) ===
 	VF_ARRAY="[]"
 	declare -a flist=()
 	if ((TOTALVFS > 0)); then
-		for VF_LINK in /sys/bus/pci/devices/0000:"$PCI_ADDR"/virtfn*; do
+		for VF_LINK in /sys/bus/pci/devices/"$SYSFS_ADDR"/virtfn*; do
 			[[ -L $VF_LINK ]] || continue
 			VF_PATH=$(readlink -f "$VF_LINK")
-			VF_ADDR=${VF_PATH##*/} # e.g. "0000:65:00.2"
-			VF_BDF="${VF_ADDR:5}"  # "65:00.2"
+			# Keep the full domain-qualified address (e.g. "0000:65:00.2")
+			VF_BDF=${VF_PATH##*/}
 
 			# For NVIDIA SR-IOV, check for vGPU (mdev) on the VF itself
 			if [[ "$VENDOR_ID" == "10de" ]]; then
@@ -817,10 +918,7 @@ for LINE in "${LINES[@]}"; do
 				process_mdev_instances "$VF_MDEV_BASE" "$VF_BDF"
 			fi
 
-			DOMAIN="0x0000"
-			BUS="0x${VF_BDF:0:2}"
-			SLOT="0x${VF_BDF:3:2}"
-			FUNC="0x${VF_BDF:6:1}"
+			parse_pci_address "$VF_BDF"
 
 			# Determine vf_profile using nvidia-smi information
 			VF_PROFILE=""
@@ -835,8 +933,10 @@ for LINE in "${LINES[@]}"; do
 				# For NVIDIA GPUs, check current vGPU type
 				current_vgpu_type=$(get_current_vgpu_type "$VF_PATH")
 				if [[ "$current_vgpu_type" != "0" ]]; then
-					# Get profile info from nvidia-smi cache
-					profile_info=$(get_nvidia_profile_info "$PCI_ADDR" "$current_vgpu_type")
+					# nvidia_vgpu_profiles is keyed by the canonical full
+					# "dddd:bb:ss.f" form, so widen PCI_ADDR (which may be
+					# short for domain 0) before the cache lookup.
+					profile_info=$(get_nvidia_profile_info "$(normalize_pci_address "$PCI_ADDR")" "$current_vgpu_type")
 					IFS='|' read -r VF_PROFILE_NAME VF_MAX_INSTANCES VF_VIDEO_RAM VF_MAX_HEADS VF_MAX_RESOLUTION_X VF_MAX_RESOLUTION_Y <<< "$profile_info"
 					VF_PROFILE="$VF_PROFILE_NAME"
 				fi
@@ -853,12 +953,17 @@ for LINE in "${LINES[@]}"; do
 			fi
 			VF_PROFILE_JSON=$(json_escape "$VF_PROFILE")
 
-			# Determine which VM uses this VF_BDF
-			raw="${pci_to_vm[$VF_BDF]:-}"
+			# Determine which VM uses this VF_BDF (normalize for map lookup)
+			raw="${pci_to_vm[$(normalize_pci_address "$VF_BDF")]:-}"
 			USED_JSON=$(to_json_vm "$raw")
 
+			# For backward-compat JSON output, strip the default "0000:" domain
+			# prefix so domain-0 VFs still print as "65:00.2" rather than the
+			# full "0000:65:00.2". Non-zero domains are preserved unchanged.
+			VF_DISPLAY_ADDR="${VF_BDF#0000:}"
+
 			flist+=(
-				"{\"vf_pci_address\":\"$VF_BDF\",\"vf_profile\":$VF_PROFILE_JSON,\"max_instances\":$VF_MAX_INSTANCES,\"video_ram\":$VF_VIDEO_RAM,\"max_heads\":$VF_MAX_HEADS,\"max_resolution_x\":$VF_MAX_RESOLUTION_X,\"max_resolution_y\":$VF_MAX_RESOLUTION_Y,\"libvirt_address\":{\"domain\":\"$DOMAIN\",\"bus\":\"$BUS\",\"slot\":\"$SLOT\",\"function\":\"$FUNC\"},\"used_by_vm\":$USED_JSON}")
+				"{\"vf_pci_address\":\"$VF_DISPLAY_ADDR\",\"vf_profile\":$VF_PROFILE_JSON,\"max_instances\":$VF_MAX_INSTANCES,\"video_ram\":$VF_VIDEO_RAM,\"max_heads\":$VF_MAX_HEADS,\"max_resolution_x\":$VF_MAX_RESOLUTION_X,\"max_resolution_y\":$VF_MAX_RESOLUTION_Y,\"libvirt_address\":{\"domain\":\"$DOMAIN\",\"bus\":\"$BUS\",\"slot\":\"$SLOT\",\"function\":\"$FUNC\"},\"used_by_vm\":$USED_JSON}")
 		done
 		if [ ${#flist[@]} -gt 0 ]; then
 			VF_ARRAY="[$(
@@ -882,10 +987,7 @@ for LINE in "${LINES[@]}"; do
 	if [[ ${#vlist[@]} -eq 0 && ${#flist[@]} -eq 0 ]]; then
 		FP_ENABLED=1
 	fi
-	DOMAIN="0x0000"
-	BUS="0x${PCI_ADDR:0:2}"
-	SLOT="0x${PCI_ADDR:3:2}"
-	FUNC="0x${PCI_ADDR:6:1}"
+	parse_pci_address "$PCI_ADDR"
 
 	# Emit JSON
 	if $first_gpu; then

From 78a511453e769f81cce2fcf605f0c810ebac8dbe Mon Sep 17 00:00:00 2001
From: vishesh92 <vishesh92@gmail.com>
Date: Wed, 8 Apr 2026 14:32:37 +0530
Subject: [PATCH 2/6] Address comments

---
 .../kvm/resource/LibvirtGpuDef.java           | 45 +++++++++++--------
 .../kvm/resource/LibvirtGpuDefTest.java       |  8 ++--
 2 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
index 77ee9b0af31f..b33f0179fc33 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
@@ -82,33 +82,42 @@ private void generatePciXml(StringBuilder gpuBuilder) {
         // Parse the bus address into domain, bus, slot, function. Two input formats are accepted:
         //   - "dddd:bb:ss.f"  full PCI address with domain (e.g. 0000:00:02.0)
         //   - "bb:ss.f"       legacy short BDF; domain defaults to 0000
-        String domain = "0x0000";
-        String bus = "0x00";
-        String slot = "0x00";
-        String function = "0x0";
+        // Each segment is parsed as a hex integer and formatted with fixed widths
+        // (domain: 4 hex digits, bus/slot: 2 hex digits, function: 1 hex digit) to
+        // produce canonical libvirt XML values regardless of input casing or padding.
+        int domainVal = 0, busVal = 0, slotVal = 0, funcVal = 0;
 
         if (busAddress != null && !busAddress.isEmpty()) {
             String[] parts = busAddress.split(":");
             String slotFunction = null;
-            if (parts.length == 3) {
-                domain = "0x" + parts[0];
-                bus = "0x" + parts[1];
-                slotFunction = parts[2];
-            } else if (parts.length == 2) {
-                bus = "0x" + parts[0];
-                slotFunction = parts[1];
-            }
-            if (slotFunction != null) {
-                String[] slotFunctionParts = slotFunction.split("\\.");
-                if (slotFunctionParts.length > 0) {
-                    slot = "0x" + slotFunctionParts[0];
-                    if (slotFunctionParts.length > 1) {
-                        function = "0x" + slotFunctionParts[1].trim();
+            try {
+                if (parts.length == 3) {
+                    domainVal = Integer.parseInt(parts[0], 16);
+                    busVal = Integer.parseInt(parts[1], 16);
+                    slotFunction = parts[2];
+                } else if (parts.length == 2) {
+                    busVal = Integer.parseInt(parts[0], 16);
+                    slotFunction = parts[1];
+                }
+                if (slotFunction != null) {
+                    String[] slotFunctionParts = slotFunction.split("\\.");
+                    if (slotFunctionParts.length > 0) {
+                        slotVal = Integer.parseInt(slotFunctionParts[0], 16);
+                        if (slotFunctionParts.length > 1) {
+                            funcVal = Integer.parseInt(slotFunctionParts[1].trim(), 16);
+                        }
                     }
                 }
+            } catch (NumberFormatException e) {
+                // leave all values at 0 (safe defaults)
             }
         }
 
+        String domain = String.format("0x%04x", domainVal);
+        String bus = String.format("0x%02x", busVal);
+        String slot = String.format("0x%02x", slotVal);
+        String function = String.format("0x%x", funcVal);
+
         gpuBuilder.append("    <address domain='").append(domain).append("' bus='").append(bus).append("' slot='")
                 .append(slot).append("' function='").append(function.trim()).append("'/>\n");
         gpuBuilder.append("  </source>\n");
diff --git a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
index 6b8eac8e2231..efdc740fa67b 100644
--- a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
@@ -156,13 +156,15 @@ public void testGpuDef_withFullPciAddressNonZeroDomain() {
     }
 
     @Test
-    public void testGpuDef_withFullPciAddressWideDomain() {
+    public void testGpuDef_withNvidiaStyleEightDigitDomain() {
+        // nvidia-smi reports PCI addresses with an 8-digit domain (e.g. "00000001:af:00.1").
+        // generatePciXml must normalize it to the canonical 4-digit form "0x0001".
         LibvirtGpuDef gpuDef = new LibvirtGpuDef();
         VgpuTypesInfo pciGpuInfo = new VgpuTypesInfo(
                 GpuDevice.DeviceType.PCI,
                 "passthrough",
                 "passthrough",
-                "10000:af:00.1",
+                "00000001:af:00.1",
                 "10de",
                 "NVIDIA Corporation",
                 "1b38",
@@ -172,7 +174,7 @@ public void testGpuDef_withFullPciAddressWideDomain() {
 
         String gpuXml = gpuDef.toString();
 
-        assertTrue(gpuXml.contains("<address domain='0x10000' bus='0xaf' slot='0x00' function='0x1'/>"));
+        assertTrue(gpuXml.contains("<address domain='0x0001' bus='0xaf' slot='0x00' function='0x1'/>"));
     }
 
     @Test

From 8ead015c296f0dd7f094c0b7a615a411a6b65152 Mon Sep 17 00:00:00 2001
From: Piet Braat <piet@phiea.nl>
Date: Fri, 3 Apr 2026 09:06:56 +0200
Subject: [PATCH 3/6] Add Display controller to GPU class check

this adds support for the amd instinct mi2xx accelorator crards in the discovery script.
---
 scripts/vm/hypervisor/kvm/gpudiscovery.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/vm/hypervisor/kvm/gpudiscovery.sh b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
index e7c40c8810ca..7aec0369da7a 100755
--- a/scripts/vm/hypervisor/kvm/gpudiscovery.sh
+++ b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
@@ -848,7 +848,7 @@ for LINE in "${LINES[@]}"; do
 	fi
 
 	# Only process GPU classes (3D controller)
-	if [[ ! "$PCI_CLASS" =~ (3D\ controller|Processing\ accelerators) ]]; then
+	if [[ ! "$PCI_CLASS" =~ (3D\ controller|Processing\ accelerators|Display\ controller) ]]; then
 		continue
 	fi
 

From 6fa2a88cc64ce385449e53ed24e1da4e6b2acf92 Mon Sep 17 00:00:00 2001
From: vishesh92 <vishesh92@gmail.com>
Date: Wed, 8 Apr 2026 14:37:03 +0530
Subject: [PATCH 4/6] fixup

---
 scripts/vm/hypervisor/kvm/gpudiscovery.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/vm/hypervisor/kvm/gpudiscovery.sh b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
index 7aec0369da7a..3ee902503347 100755
--- a/scripts/vm/hypervisor/kvm/gpudiscovery.sh
+++ b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
@@ -847,7 +847,7 @@ for LINE in "${LINES[@]}"; do
 		continue
 	fi
 
-	# Only process GPU classes (3D controller)
+	# Only process PCI classes - 3D controller, Processing accelerators, Display controller
 	if [[ ! "$PCI_CLASS" =~ (3D\ controller|Processing\ accelerators|Display\ controller) ]]; then
 		continue
 	fi

From 8d0979003cda743c66e106e9ab2b92ebf5f78303 Mon Sep 17 00:00:00 2001
From: vishesh92 <vishesh92@gmail.com>
Date: Wed, 8 Apr 2026 15:40:39 +0530
Subject: [PATCH 5/6] Address comments

---
 .../kvm/resource/LibvirtGpuDef.java           | 22 +++++-----
 .../kvm/resource/LibvirtGpuDefTest.java       | 33 ++++++++++++++
 scripts/vm/hypervisor/kvm/gpudiscovery.sh     | 44 ++++++++++---------
 3 files changed, 67 insertions(+), 32 deletions(-)

diff --git a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
index b33f0179fc33..d3765c01ccbc 100644
--- a/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
+++ b/plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDef.java
@@ -89,8 +89,8 @@ private void generatePciXml(StringBuilder gpuBuilder) {
 
         if (busAddress != null && !busAddress.isEmpty()) {
             String[] parts = busAddress.split(":");
-            String slotFunction = null;
             try {
+                String slotFunction;
                 if (parts.length == 3) {
                     domainVal = Integer.parseInt(parts[0], 16);
                     busVal = Integer.parseInt(parts[1], 16);
@@ -98,18 +98,18 @@ private void generatePciXml(StringBuilder gpuBuilder) {
                 } else if (parts.length == 2) {
                     busVal = Integer.parseInt(parts[0], 16);
                     slotFunction = parts[1];
+                } else {
+                    throw new IllegalArgumentException("Invalid PCI bus address format: '" + busAddress + "'");
                 }
-                if (slotFunction != null) {
-                    String[] slotFunctionParts = slotFunction.split("\\.");
-                    if (slotFunctionParts.length > 0) {
-                        slotVal = Integer.parseInt(slotFunctionParts[0], 16);
-                        if (slotFunctionParts.length > 1) {
-                            funcVal = Integer.parseInt(slotFunctionParts[1].trim(), 16);
-                        }
-                    }
+                String[] sf = slotFunction.split("\\.");
+                if (sf.length == 2) {
+                    slotVal = Integer.parseInt(sf[0], 16);
+                    funcVal = Integer.parseInt(sf[1].trim(), 16);
+                } else {
+                    throw new IllegalArgumentException("Invalid PCI bus address format: '" + busAddress + "'");
                 }
             } catch (NumberFormatException e) {
-                // leave all values at 0 (safe defaults)
+                throw new IllegalArgumentException("Invalid PCI bus address format: '" + busAddress + "'", e);
             }
         }
 
@@ -119,7 +119,7 @@ private void generatePciXml(StringBuilder gpuBuilder) {
         String function = String.format("0x%x", funcVal);
 
         gpuBuilder.append("    <address domain='").append(domain).append("' bus='").append(bus).append("' slot='")
-                .append(slot).append("' function='").append(function.trim()).append("'/>\n");
+                .append(slot).append("' function='").append(function).append("'/>\n");
         gpuBuilder.append("  </source>\n");
         gpuBuilder.append("</hostdev>\n");
     }
diff --git a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
index efdc740fa67b..e6f63e852f85 100644
--- a/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
+++ b/plugins/hypervisors/kvm/src/test/java/com/cloud/hypervisor/kvm/resource/LibvirtGpuDefTest.java
@@ -221,6 +221,39 @@ public void testGpuDef_withLegacyShortBdfDefaultsDomainToZero() {
         assertTrue(gpuXml.contains("<address domain='0x0000' bus='0xaf' slot='0x00' function='0x0'/>"));
     }
 
+    @Test
+    public void testGpuDef_withInvalidBusAddressThrows() {
+        String[] invalidAddresses = {
+                "notahex:00.0",          // non-hex bus
+                "gg:00:02.0",            // non-hex domain
+                "00:02:03:04",           // too many colon-separated parts
+                "00",                    // missing slot/function
+                "00:02",                 // missing function (no dot)
+                "00:02.0.1",             // extra dot in ss.f
+        };
+        for (String addr : invalidAddresses) {
+            LibvirtGpuDef gpuDef = new LibvirtGpuDef();
+            VgpuTypesInfo info = new VgpuTypesInfo(
+                    GpuDevice.DeviceType.PCI,
+                    "passthrough",
+                    "passthrough",
+                    addr,
+                    "10de",
+                    "NVIDIA Corporation",
+                    "1b38",
+                    "Tesla T4"
+            );
+            gpuDef.defGpu(info);
+            try {
+                String ignored = gpuDef.toString();
+                fail("Expected IllegalArgumentException for address: " + addr + " but got: " + ignored);
+            } catch (IllegalArgumentException e) {
+                assertTrue("Exception message should contain the bad address",
+                        e.getMessage().contains(addr));
+            }
+        }
+    }
+
     @Test
     public void testGpuDef_withNullDeviceType() {
         LibvirtGpuDef gpuDef = new LibvirtGpuDef();
diff --git a/scripts/vm/hypervisor/kvm/gpudiscovery.sh b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
index 3ee902503347..0c21669f03ba 100755
--- a/scripts/vm/hypervisor/kvm/gpudiscovery.sh
+++ b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
@@ -448,16 +448,12 @@ parse_nvidia_vgpu_profiles() {
 			# normalize_pci_address output used at lookup time. Short
 			# addresses ("AF:00.0") are widened by prepending domain 0.
 			if [[ $gpu_address =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
-				gpu_address=$(printf "%04x:%s:%s.%s" \
-					"0x${BASH_REMATCH[1]}" \
-					"${BASH_REMATCH[2],,}" \
-					"${BASH_REMATCH[3],,}" \
-					"${BASH_REMATCH[4],,}")
+				gpu_address=$(printf "%04x:%02x:%02x.%x" \
+					"0x${BASH_REMATCH[1]}" "0x${BASH_REMATCH[2]}" \
+					"0x${BASH_REMATCH[3]}" "0x${BASH_REMATCH[4]}")
 			elif [[ $gpu_address =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
-				gpu_address=$(printf "0000:%s:%s.%s" \
-					"${BASH_REMATCH[1],,}" \
-					"${BASH_REMATCH[2],,}" \
-					"${BASH_REMATCH[3],,}")
+				gpu_address=$(printf "0000:%02x:%02x.%x" \
+					"0x${BASH_REMATCH[1]}" "0x${BASH_REMATCH[2]}" "0x${BASH_REMATCH[3]}")
 			else
 				gpu_address="${gpu_address,,}"
 			fi
@@ -557,15 +553,15 @@ get_nvidia_profile_info() {
 parse_pci_address() {
 	local addr="$1"
 	if [[ $addr =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
-		DOMAIN="0x${BASH_REMATCH[1]}"
-		BUS="0x${BASH_REMATCH[2]}"
-		SLOT="0x${BASH_REMATCH[3]}"
-		FUNC="0x${BASH_REMATCH[4]}"
+		DOMAIN=$(printf "0x%04x" "0x${BASH_REMATCH[1]}")
+		BUS=$(printf "0x%02x" "0x${BASH_REMATCH[2]}")
+		SLOT=$(printf "0x%02x" "0x${BASH_REMATCH[3]}")
+		FUNC=$(printf "0x%x" "0x${BASH_REMATCH[4]}")
 	elif [[ $addr =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
 		DOMAIN="0x0000"
-		BUS="0x${BASH_REMATCH[1]}"
-		SLOT="0x${BASH_REMATCH[2]}"
-		FUNC="0x${BASH_REMATCH[3]}"
+		BUS=$(printf "0x%02x" "0x${BASH_REMATCH[1]}")
+		SLOT=$(printf "0x%02x" "0x${BASH_REMATCH[2]}")
+		FUNC=$(printf "0x%x" "0x${BASH_REMATCH[3]}")
 	else
 		DOMAIN="0x0000"
 		BUS="0x00"
@@ -574,14 +570,20 @@ parse_pci_address() {
 	fi
 }
 
-# Normalize a PCI address to its full domain-qualified form ("dddd:bb:ss.f").
-# Short addresses are widened by prepending domain "0000".
+# Normalize a PCI address to its canonical full domain-qualified form
+# ("dddd:bb:ss.f", lowercase, zero-padded). Both "dddd:bb:ss.f" (full) and
+# "bb:ss.f" (short, domain 0) inputs are accepted.
 normalize_pci_address() {
 	local addr="$1"
-	if [[ $addr =~ ^[0-9A-Fa-f]+:[0-9A-Fa-f]+:[0-9A-Fa-f]+\.[0-9A-Fa-f]+$ ]]; then
-		echo "$addr"
+	if [[ $addr =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
+		printf "%04x:%02x:%02x.%x\n" \
+			"0x${BASH_REMATCH[1]}" "0x${BASH_REMATCH[2]}" \
+			"0x${BASH_REMATCH[3]}" "0x${BASH_REMATCH[4]}"
+	elif [[ $addr =~ ^([0-9A-Fa-f]+):([0-9A-Fa-f]+)\.([0-9A-Fa-f]+)$ ]]; then
+		printf "0000:%02x:%02x.%x\n" \
+			"0x${BASH_REMATCH[1]}" "0x${BASH_REMATCH[2]}" "0x${BASH_REMATCH[3]}"
 	else
-		echo "0000:$addr"
+		echo "$addr"
 	fi
 }
 

From 4e7a8346b7428889b5f286ede006882d5c2a9df0 Mon Sep 17 00:00:00 2001
From: vishesh92 <vishesh92@gmail.com>
Date: Wed, 8 Apr 2026 16:08:27 +0530
Subject: [PATCH 6/6] Address comments

---
 scripts/vm/hypervisor/kvm/gpudiscovery.sh | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/scripts/vm/hypervisor/kvm/gpudiscovery.sh b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
index 0c21669f03ba..524f86241860 100755
--- a/scripts/vm/hypervisor/kvm/gpudiscovery.sh
+++ b/scripts/vm/hypervisor/kvm/gpudiscovery.sh
@@ -704,7 +704,7 @@ for VM in "${VMS[@]}"; do
 	# -- PCI hostdevs: use xmlstarlet to extract the full domain:bus:slot.func
 	# for all PCI host devices. libvirt's <address> element may omit the domain
 	# attribute, in which case we default to 0.
-	while read -r dom bus slot func; do
+	while IFS=: read -r dom bus slot func; do
 		[[ -n "$bus" && -n "$slot" && -n "$func" ]] || continue
 		[[ -n "$dom" ]] || dom="0"
 		# Format to match lspci -D output (e.g., 0000:01:00.0) by padding with zeros
@@ -715,9 +715,9 @@ for VM in "${VMS[@]}"; do
 		BDF="${dom_fmt}:${bus_fmt}:${slot_fmt}.${func_fmt}"
 		pci_to_vm["$BDF"]="$VM"
 	done < <(echo "$xml" | xmlstarlet sel -T -t -m "//hostdev[@type='pci']/source/address" \
-		-v "substring-after(@domain, '0x')" -o " " \
-		-v "substring-after(@bus, '0x')" -o " " \
-		-v "substring-after(@slot, '0x')" -o " " \
+		-v "substring-after(@domain, '0x')" -o ":" \
+		-v "substring-after(@bus, '0x')" -o ":" \
+		-v "substring-after(@slot, '0x')" -o ":" \
 		-v "substring-after(@function, '0x')" -n 2>/dev/null || true)
 
 	# -- MDEV hostdevs: use xmlstarlet to extract UUIDs --
@@ -989,6 +989,8 @@ for LINE in "${LINES[@]}"; do
 	if [[ ${#vlist[@]} -eq 0 && ${#flist[@]} -eq 0 ]]; then
 		FP_ENABLED=1
 	fi
+
+	# Sets global DOMAIN/BUS/SLOT/FUNC for JSON output below
 	parse_pci_address "$PCI_ADDR"
 
 	# Emit JSON