[Query] Unable to probe reserved-memory carveouts in DomU with Xen

Hi all,

I have been trying to use reserved-memory carveouts in DomU, but failing constantly.

This is the log from Dom1 boot:

[    0.000000] earlycon: uart8250 at MMIO32 0x0000000053914000 (options '115200n
8')
[    0.000000] printk: legacy bootconsole [uart8250] enabled
[    0.000000] Xen 4.21 support found
[    0.000000] efi: UEFI not found.
*[    0.000000] OF: reserved mem: Reserved memory: No reserved-memory node in the DT*
[    0.000000] Zone ranges:
[    0.000000]   DMA      [mem 0x0000000040000000-0x0000000051ffffff]
[    0.000000]   DMA32    empty
[    0.000000]   Normal   empty
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000040000000-0x0000000051ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000040000000-0x0000000051ffffff]
[    0.000000] On node 0, zone DMA: 24576 pages in unavailable ranges
[    0.000000] cma: Reserved 32 MiB at 0x000000004f800000

This is my passthrough.dts:

    1 /*
    2 * This is a partial DT for passthrough node to DomU.
    3 */
    4 #include <dt-bindings/interrupt-controller/irq.h>
    5 #include <dt-bindings/interrupt-controller/arm-gic.h>
    6 
    7 /dts-v1/;
    8 
    9 / {
   10         #address-cells = <2>;
   11         #size-cells = <1>;
   12 
~  13         reserved-memory {
~  14                 #address-cells = <2>;
~  15                 #size-cells = <2>;
+  16                 ranges;
+  17 
+  18                 /* CMA region for framebuffer allocation */
+  19                 linux,cma {
+  20                         compatible = "shared-dma-pool";
+  21                         reusable;
+  22                         size = <0x00 0x08000000>; /* 128MB CMA pool */
+  23                         linux,cma-default;
+  24                 };
   25         };
   26 
   27         passthrough {
   28                 compatible = "simple-bus";
   29                 ranges;
   30                 #address-cells = <2>;
   31                 #size-cells = <1>;
   32 
   33                 misc_clk: misc_clk {
   34                         #clock-cells = <0>;
   35                         clock-frequency = <100000000>;
   36                         compatible = "fixed-clock";
   37                 };

   73                 uart@53914000 {
   74                         compatible = "ns16550a";
   75                         reg = <0x00 0x53914000 0x1000>;
~_ 76                         interrupts = <0 302 4>;
   77                         reg-shift = <2>;
   78                         reg-io-width = <4>;
   79                         clocks = <&misc_clk>;
   80                         oversampling-rate = <16>;
   81                         programmable-char-timeout = <4>;
   82                         status = "okay";
   83                         xen,path = "/bus@100000/bus@22000000/uart@53914000";
   84                         xen,reg = <0x0 0x53914000 0x1000 0x0 0x53914000>;
   85                         xen,force-assign-without-iommu;
   86                 };
   87          };

   88    };


And this is my dom1.cfg file:

 1 name = "dom1"
 2 memory = 256
 3 vcpus = 4
 4 
 5 kernel = "/boot/xen-dom1/Image"
 6 extra = "console=ttyS0,115200n8 earlycon=uart8250,mmio32,0x53914000,115200n8 loglevel=8 root=/dev/xvda rw"
 7 
 8 # UART1 (0x53914000) passthrough to Dom1 console
 9 iomem = ["0x53914,1"]
11 irqs = [ 334 ]
12 dtdev = [ "/bus@100000/bus@22000000/uart@53914000"]
13 vif = ["script=vif-route"]
14 device_tree = "/boot/xen-dom1/passthrough.dtb"
15 #  
17 disk = ["phy:/dev/vda2,xvda,rw"]


Am I doing something wrong? Any help or debugging leads would be really appreciated...

Thank you,
Beleswar