Re: [PATCH v2] virtio_mem: fix panic on mb_states indexing overflow

From: Eric Ren
Date: Tue Dec 21 2021 - 09:24:51 EST


Hi David,

在 12/21/21 9:53 PM, David Hildenbrand 写道:
Hi Eric,

_vm->sbm.first_mb_id == 0
^ that's precisely what I meant.
Ah, finally got it!

How could it *ever* be safe on x86-64 to let a virtio-mem device start
on physical address 0, eventually overlapping essentially all DMA, the
BIOS and the PCI hole.
You're right! That clears my doubt why this "issue" can live so long there... util I see it.

Yes, my setup is a very hacking enviroment. The device region start addr is wrongly
assigned to 0!

So, let's just drop this patch.

Eric

Thus my question: Is this a "fix" for x86-64 or is this a "prepare for"
for !x86-64 (e.g., arm64).

If it's a fix, we want proper "Fixes:" and "Cc: stable" tags. But I
assume this is much rather a preparation for another architecture than
x86-64.

Thanks!