Add qvm doctor command to diagnose and fix common issues

internal/vm/qemu.go

@@ -7,42 +7,30 @@ import (
 	"strconv"
 )
 
+// buildQEMUCommand builds the QEMU command line for virtiofsd-based mounts.
+// Uses vhost-user-fs-pci devices which support hot-plugging.
 func buildQEMUCommand(cfg *config.Config, sshPort int, mounts []virtiofsd.Mount) []string {
-	args := []string{
-		"qemu-system-x86_64",
-		"-enable-kvm",
-	}
-
 	memSize := cfg.VM.Memory
-	args = append(args,
+
+	// vhost-user-fs requires shared memory backend
+	args := []string{
+		"-machine", "q35",
+		"-accel", "kvm",
+		"-cpu", "host",
 		"-object", fmt.Sprintf("memory-backend-memfd,id=mem,size=%s,share=on", memSize),
 		"-numa", "node,memdev=mem",
-	)
-
-	args = append(args,
 		"-smp", strconv.Itoa(cfg.VM.CPUs),
-	)
-
-	args = append(args,
-		"-drive", fmt.Sprintf("if=virtio,file=%s,format=qcow2", config.Overlay),
-	)
-
-	args = append(args,
-		"-nic", fmt.Sprintf("user,model=virtio-net-pci,hostfwd=tcp::%d-:22", sshPort),
-	)
-
-	args = append(args,
-		"-serial", fmt.Sprintf("file:%s", config.SerialLog),
-	)
-
-	args = append(args,
-		"-qmp", fmt.Sprintf("unix:%s,server,nowait", config.QMPSocket),
-	)
-
-	args = append(args,
 		"-display", "none",
-	)
+		"-daemonize",
+		"-pidfile", config.PIDFile,
+		"-drive", fmt.Sprintf("file=%s,if=virtio,format=qcow2", config.Overlay),
+		"-netdev", fmt.Sprintf("user,id=n0,hostfwd=tcp::%d-:22", sshPort),
+		"-device", "virtio-net-pci,netdev=n0",
+		"-serial", fmt.Sprintf("file:%s", config.SerialLog),
+		"-qmp", fmt.Sprintf("unix:%s,server,nowait", config.QMPSocket),
+	}
 
+	// Add vhost-user-fs devices for each mount
 	for _, mount := range mounts {
 		args = append(args,
 			"-chardev", fmt.Sprintf("socket,id=%s,path=%s", mount.Tag, mount.SocketPath),