Messages in this thread | | | Subject | Re: [RFC PATCH 0/5] madvise MADV_DOEXEC | From | Steven Sistare <> | Date | Fri, 31 Jul 2020 13:15:34 -0400 |
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On 7/31/2020 12:56 PM, Jason Gunthorpe wrote: > On Fri, Jul 31, 2020 at 12:11:52PM -0400, Steven Sistare wrote: >>> Your preservation-across-exec use-case might or might not need the >>> VMA to be mapped at the same address. >> >> It does. qemu registers memory with vfio which remembers the va's in kernel >> metadata for the device. > > Once the memory is registered with vfio the VA doesn't matter, vfio > will keep the iommu pointing at the same physical pages no matter > where they are mapped.
Yes, but there are other code paths that compute and use offsets between va and the base va. Mapping at a different va in the new process breaks vfio; I have tried it.
- Steve
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