On Fri, Sep 13, 2024 at 6:08 PM Du, Fan fan.du@intel.com wrote:
...
Hello,
This patchset is our exploration of how to support 1G pages in guest_memfd, and how the pages will be used in Confidential VMs.
The patchset covers:
- How to get 1G pages
- Allowing mmap() of guest_memfd to userspace so that both private and
shared
Hi Ackerley
Thanks for posting new version :)
W.r.t above description and below patch snippet from Patch 26-29, Does this new design aim to backup shared and private GPA with a single Hugetlb spool which equal VM instance total memory?
Yes.
By my understanding, before this new changes, shared memfd and gmem fd has dedicate hugetlb pool, that's two copy/reservation of hugetlb spool.
Selftests attached to this series use single gmem fd to back guest memory.
Does Qemu require new changes as well? I'd like to have a test of this series if you can share Qemu branch?
We are going to discuss this RFC series and related issues at LPC. Once the next steps are finalized, the plan will be to send out an improved version. You can use/modify the selftests that are part of this series to test this feature with software protected VMs for now.
Qemu will require changes for this feature on top of already floated gmem integration series [1] that adds software protected VM support to Qemu. If you are interested in testing this feature with TDX VMs then it needs multiple series to set up the right test environment (including [2]). We haven't considered posting Qemu patches and it will be a while before we can get to it.
[1] https://patchew.org/QEMU/20230914035117.3285885-1-xiaoyao.li@intel.com/ [2] https://patchwork.kernel.org/project/kvm/cover/20231115071519.2864957-1-xiao...