Messages in this thread | | | Subject | Re: [PATCH] virtio_mem: prevent overflow with subblock size | From | David Hildenbrand <> | Date | Mon, 8 Jun 2020 09:34:51 +0200 |
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On 08.06.20 09:12, teawater wrote: > > >> 2020年6月8日 14:58,David Hildenbrand <david@redhat.com> 写道: >> >> On 08.06.20 08:14, Michael S. Tsirkin wrote: >>> If subblock size is large (e.g. 1G) 32 bit math involving it >>> can overflow. Rather than try to catch all instances of that, >>> let's tweak block size to 64 bit. >> >> I fail to see where we could actually trigger an overflow. The reported >> warning looked like a false positive to me. >> >>> >>> It ripples through UAPI which is an ABI change, but it's not too late to >>> make it, and it will allow supporting >4Gbyte blocks while might >>> become necessary down the road. >>> >> >> This might break cloud-hypervisor, who's already implementing this >> protocol upstream (ccing Hui). >> https://github.com/cloud-hypervisor/cloud-hypervisor/blob/master/vm-virtio/src/mem.rs >> >> (blocks in the gigabyte range were never the original intention of >> virtio-mem, but I am not completely opposed to that) > > If you think virtio_mem need this patch, I think cloud-hypervisor should follow this update (I will post PR for it).
Thanks Hui. So we can still do last-minute changes if we all agree it makes sense.
@MST can you rephrase the patch description to highlight that this is a preparation for the future only and not actually currently broken? "virtio-mem: convert device block size into 64bit" ...
With that
Acked-by: David Hildenbrand <david@redhat.com>
-- Thanks,
David / dhildenb
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