On 16.12.25 17:00, Harry Ramsey wrote:
Hello Harry > [You don't often get email from [email protected]. Learn why this is > important at https://aka.ms/LearnAboutSenderIdentification ] > > On 04/12/2025 13:37, Oleksandr Tyshchenko wrote: >> Thank you very much for offering to test this on Arm32 platforms. >> >> The primary goal of the test is to confirm that the new, calculated DTB >> buffer size of 3072 bytes is sufficient for a worst-case Arm32 dom0less >> guest. The expected result is that Xen boots successfully, and the >> regular dom0less guest is created without any panics. >> >> The ideal test configuration would be a dom0less guest with the >> following configuration: >> - The vCPU count set to the maximum for Arm32, which is 8, the vCPU >> nodes should ideally contain "clock-frequency" property. >> - Any other features that add nodes to the guest device tree enabled >> (e.g., hypervisor, reserved-memory, pl011 nodes are present, etc), to >> create the largest possible "base" FDT size. >> >> The test would involve applying the current patch, and the diff below: >> >> diff --git a/xen/common/device-tree/dom0less-build.c >> b/xen/common/device-tree/dom0less-build.c >> index 38a5830813..e95f42d1e1 100644 >> --- a/xen/common/device-tree/dom0less-build.c >> +++ b/xen/common/device-tree/dom0less-build.c >> @@ -577,6 +577,9 @@ static int __init prepare_dtb_domU(struct domain *d, >> struct kernel_info *kinfo) >> if ( ret < 0 ) >> goto err; >> >> + printk("Final compacted FDT size is: %d bytes\n", >> fdt_totalsize(kinfo->fdt)); >> + printk("Predefined FDT size is: %d bytes\n", DOMU_DTB_SIZE); >> + >> return 0; >> >> err: >> >> >> Please let me know what you get. Thanks again. > > I have tested this and can confirm it boots into Linux with an 8-core > setup. Here are the values I got: > (XEN) Final compacted FDT size is: 1127 bytes > (XEN) Predefined FDT size is: 3072 bytes > > Tested-by: Harry Ramsey <[email protected]> Thank you very much for testing on the Arm32 platform and confirming that the proposed size is sufficient! > > Thanks, > Harry Ramsey
