Hi Peng,
On 31/05/16 10:58, Peng Fan wrote:
So, need to make sure boot pages are ready before setup xenheap mappings.
init_boot_pages is using mfn_to_virt (see bootmem_region_add), which cannot
work until xenheap_mfn_start is initialized. This is done by
setup_xenheap_mappings.
My bad. I did not catch this point. Thanks for correcting me.
I would be happy to give you hint on how to solve this, but I am not sure to
fully understand your issue. Can you give more details?
I did not met issue on my platform. I just think the logic of this piece code
may cause errors on platform with large memory (>512GB).
How about the following patch?
First loop all the memory banks and calculate ram_size/ram_start/ram_end,
then set xenheap_virt_end/start and xenheap_mfn_end.
Now readly for init boot pages and setup_xenheap_mappings.
Have you tested this patch? I would be surprised to see it working.
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index dcb23b7..d3a3af3 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -635,13 +635,24 @@ static void __init setup_mm(unsigned long dtb_paddr,
size_t dtb_size)
paddr_t bank_start = bootinfo.mem.bank[bank].start;
paddr_t bank_size = bootinfo.mem.bank[bank].size;
paddr_t bank_end = bank_start + bank_size;
- paddr_t s, e;
ram_size = ram_size + bank_size;
ram_start = min(ram_start,bank_start);
ram_end = max(ram_end,bank_end);
+ }
- setup_xenheap_mappings(bank_start>>PAGE_SHIFT, bank_size>>PAGE_SHIFT);
+ total_pages += ram_size >> PAGE_SHIFT;
+
+ xenheap_virt_end = XENHEAP_VIRT_START + ram_end - ram_start;
XENHEAP_VIRT_START will be replaced by xenheap_virt_start which is not
initialized at this time. It is done by setup_xenheap_mappings.
In any case, even if the variable are correctly setup the underlying
page table are not present.
The easiest way I can think to fix the problem is splitting the bank
with chunk of 512GB and calling setup_xenheap_mappings, init_boot_pages
for each chunk.
It is not the nicest way, so I will happy if you find a better one.
Regards,
--
Julien Grall
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