Hi Gavin, Thanks for the reply. I am new to Linux dev in general and not familiar with the ACPI table, but I will research in the area and give it a try.
Sorry for the late response. -Yusuf On Fri, Jun 9, 2023, 8:36 PM Gavin Shan <gs...@redhat.com> wrote: > Hi Mohd, > > On 6/10/23 10:01 AM, Mohd Yusuf Abdul Hamid wrote: > > I am trying to reserve a portion of the system memory in QEMU (arm64 > virt), v7.2.1 - but the kernel never honors the reserved memory area and > keeps using the area. > > > > Say, I dumped out DTB and added: > > > > reserved-memory { > > #address-cells = <0x02>; > > #size-cells = <0x02>; > > > > rsvdram@50000000 { > > no-map; > > reg = <0x00 0x50000000 0x00 0x20000000>; > > }; > > }; > > > > When booted, /proc/iomem still shows the kernel is using the entire > space - eg 2GB. > > > > Is this a supported feature or I would need to modify the virt.c and > define scratch area for some device driver scratch area. > > > > It relies on the guest kernel to handle the device-tree and the > device-tree node > for the reserved map. I doubt if you had ACPI over device-tree in the > guest kernel's > configuration. In this case, the reserved memory regions need to be > specified in > ACPI tables instead of device-tree. > > Thanks, > Gavin > >