On 25/07/2022 14:10, Jan Beulich wrote:
> Quite obviously to determine the split condition successive pages'
> attributes need to be evaluated, not always those of the initial page.
>
> Fixes: 72b02bc75b47 ("xen/heap: pass order to free_heap_pages() in heap init")
> Signed-off-by: Jan Beulich <jbeul...@suse.com>
> ---
> Part of the problem was already introduced in 24a53060bd37 ("xen/heap:
> Split init_heap_pages() in two"), but there it was still benign.This also fixes the crash that XenRT found on loads of hardware, which looks something like: (XEN) NUMA: Allocated memnodemap from 105bc81000 - 105bc92000 (XEN) NUMA: Using 8 for the hash shift. (XEN) Early fatal page fault at e008:ffff82d04022ae1e (cr2=00000000000000b8, ec=0002) (XEN) ----[ Xen-4.17.0 x86_64 debug=y Not tainted ]---- (XEN) CPU: 0 (XEN) RIP: e008:[<ffff82d04022ae1e>] common/page_alloc.c#free_heap_pages+0x2dd/0x850 ... (XEN) Xen call trace: (XEN) [<ffff82d04022ae1e>] R common/page_alloc.c#free_heap_pages+0x2dd/0x850 (XEN) [<ffff82d04022dd64>] F common/page_alloc.c#init_heap_pages+0x55f/0x720 (XEN) [<ffff82d040415234>] F end_boot_allocator+0x187/0x1e7 (XEN) [<ffff82d040452337>] F __start_xen+0x1a06/0x2779 (XEN) [<ffff82d040204344>] F __high_start+0x94/0xa0 Debugging shows that it's always a block which crosses node 0 and 1, where avail[1] has yet to be initialised. What I'm confused by is how this manages to manifest broken swiotlb issues without Xen crashing. ~Andrew
