From 27906ae23668d8e28c6620bdb63e5a5f36be1d9c Mon Sep 17 00:00:00 2001
From: illustris <rharikrishnan95@gmail.com>
Date: Tue, 14 Apr 2026 01:34:02 +0530
Subject: [PATCH] fix ParseMem to handle hotplug memory format

---
 src/internal/procfs/procfs.go      | 17 +++++++++++++++--
 src/internal/procfs/procfs_test.go | 18 ++++++++++++++++++
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/internal/procfs/procfs.go b/src/internal/procfs/procfs.go
index 116259f..2d07659 100644
--- a/src/internal/procfs/procfs.go
+++ b/src/internal/procfs/procfs.go
@@ -255,6 +255,7 @@ func ParseVcores(cmdline []string) int {
 
 // ParseMem extracts max memory in kB from cmdline.
 // Simple: -m 1024 -> 1024*1024 kB
+// Hotplug: -m size=4096M,slots=255,maxmem=524288M -> parse size= key
 // NUMA: memory-backend-ram...size=NM -> sum * 1024 kB
 func ParseMem(cmdline []string) int64 {
 	mVal := FlagValue(cmdline, "-m")
@@ -265,11 +266,23 @@ func ParseMem(cmdline []string) int64 {
 	if n, err := strconv.ParseInt(mVal, 10, 64); err == nil {
 		return n * 1024 // MB to kB
 	}
-	// NUMA case: search for memory-backend-ram in all args
+	// Hotplug/NUMA: -m size=NM,slots=N,maxmem=NM
+	// Parse the size= key from the -m value itself
+	for _, part := range strings.Split(mVal, ",") {
+		if strings.HasPrefix(part, "size=") {
+			sizeStr := strings.TrimPrefix(part, "size=")
+			if strings.HasSuffix(sizeStr, "M") {
+				sizeStr = strings.TrimSuffix(sizeStr, "M")
+				if n, err := strconv.ParseInt(sizeStr, 10, 64); err == nil {
+					return n * 1024 // MB to kB
+				}
+			}
+		}
+	}
+	// NUMA fallback: sum memory-backend-ram object sizes
 	var total int64
 	for _, arg := range cmdline {
 		if strings.Contains(arg, "memory-backend-ram") {
-			// Format: ...size=XXXM
 			for _, part := range strings.Split(arg, ",") {
 				if strings.HasPrefix(part, "size=") {
 					sizeStr := strings.TrimPrefix(part, "size=")
diff --git a/src/internal/procfs/procfs_test.go b/src/internal/procfs/procfs_test.go
index 683fb36..95c508f 100644
--- a/src/internal/procfs/procfs_test.go
+++ b/src/internal/procfs/procfs_test.go
@@ -93,6 +93,24 @@ func TestParseMem(t *testing.T) {
 			},
 			4096 * 1024, // 2048+2048 MB in kB
 		},
+		{
+			"hotplug without numa",
+			[]string{"-m", "size=131072M,slots=255,maxmem=524288M"},
+			131072 * 1024,
+		},
+		{
+			"large vm simple",
+			[]string{
+				"/usr/bin/kvm", "-id", "106",
+				"-name", "vm-106,debug-threads=on",
+				"-smp", "32,sockets=1,cores=32,maxcpus=32",
+				"-cpu", "host,+kvm_pv_eoi,+kvm_pv_unhalt",
+				"-m", "131072",
+				"-object", "iothread,id=iothread-virtio0",
+				"-machine", "type=q35+pve1",
+			},
+			131072 * 1024,
+		},
 		{
 			"missing",
 			[]string{"-smp", "4"},