On Mon, Jul 21, 2025 at 10:33:14PM -0700, Ackerley Tng wrote: > Yan Zhao <yan.y.zhao@xxxxxxxxx> writes: > > > On Wed, Jul 16, 2025 at 01:57:55PM -0700, Ackerley Tng wrote: > >> Yan Zhao <yan.y.zhao@xxxxxxxxx> writes: > >> > >> > On Thu, Jun 05, 2025 at 03:35:50PM -0700, Ackerley Tng wrote: > >> >> Yan Zhao <yan.y.zhao@xxxxxxxxx> writes: > >> >> > >> >> > On Wed, Jun 04, 2025 at 01:02:54PM -0700, Ackerley Tng wrote: > >> >> >> Hi Yan, > >> >> >> > >> >> >> While working on the 1G (aka HugeTLB) page support for guest_memfd > >> >> >> series [1], we took into account conversion failures too. The steps are > >> >> >> in kvm_gmem_convert_range(). (It might be easier to pull the entire > >> >> >> series from GitHub [2] because the steps for conversion changed in two > >> >> >> separate patches.) > >> >> > ... > >> >> >> [2] https://github.com/googleprodkernel/linux-cc/tree/gmem-1g-page-support-rfc-v2 > >> >> > > >> >> > Hi Ackerley, > >> >> > Thanks for providing this branch. > >> >> > >> >> Here's the WIP branch [1], which I initially wasn't intending to make > >> >> super public since it's not even RFC standard yet and I didn't want to > >> >> add to the many guest_memfd in-flight series, but since you referred to > >> >> it, [2] is a v2 of the WIP branch :) > >> >> > >> >> [1] https://github.com/googleprodkernel/linux-cc/commits/wip-tdx-gmem-conversions-hugetlb-2mept > >> >> [2] https://github.com/googleprodkernel/linux-cc/commits/wip-tdx-gmem-conversions-hugetlb-2mept-v2 > >> > Hi Ackerley, > >> > > >> > I'm working on preparing TDX huge page v2 based on [2] from you. The current > >> > decision is that the code base of TDX huge page v2 needs to include DPAMT > >> > and VM shutdown optimization as well. > >> > > >> > So, we think kvm-x86/next is a good candidate for us. > >> > (It is in repo https://github.com/kvm-x86/linux.git > >> > commit 87198fb0208a (tag: kvm-x86-next-2025.07.15, kvm-x86/next) Merge branch 'vmx', > >> > which already includes code for VM shutdown optimization). > >> > I still need to port DPAMT + gmem 1G + TDX huge page v2 on top it. > >> > > >> > Therefore, I'm wondering if the rebase of [2] onto kvm-x86/next can be done > >> > from your side. A straightforward rebase is sufficient, with no need for > >> > any code modification. And it's better to be completed by the end of next > >> > week. > >> > > >> > We thought it might be easier for you to do that (but depending on your > >> > bandwidth), allowing me to work on the DPAMT part for TDX huge page v2 in > >> > parallel. > >> > > >> > >> I'm a little tied up with some internal work, is it okay if, for the > > No problem. > > > >> next RFC, you base the changes that you need to make for TDX huge page > >> v2 and DPAMT on the base of [2]? > > > >> That will save both of us the rebasing. [2] was also based on (some > >> other version of) kvm/next. > >> > >> I think it's okay since the main goal is to show that it works. I'll > >> let you know when I can get to a guest_memfd_HugeTLB v3 (and all the > >> other patches that go into [2]). > > Hmm, the upstream practice is to post code based on latest version, and > > there're lots TDX relates fixes in latest kvm-x86/next. > > > > Yup I understand. > > For guest_memfd//HugeTLB I'm still waiting for guest_memfd//mmap > (managed by Fuad) to settle, and there are plenty of comments for the > guest_memfd//conversion component to iron out still, so the full update > to v3 will take longer than I think you want to wait. > > I'd say for RFCs it's okay to post patch series based on some snapshot, > since there are so many series in flight? > > To unblock you, if posting based on a snapshot is really not okay, here > are some other options I can think of: > > a. Use [2] and posting a link to a WIP tree, similar to how [2] was > done > b. Use some placeholder patches, assuming some interfaces to > guest_memfd//HugeTLB, like how the first few patches in this series > assumes some interfaces of guest_memfd with THP support, and post a > series based on assumed interfaces > > Please let me know if one of those options allow you to proceed, thanks! Do you see any issues with directly rebasing [2] onto 6.16.0-rc6? We currently prefer this approach. We have tested [2] for some time, and TDX huge page series doesn't rely on the implementation details of guest_memfd. It's ok if you are currently occupied by Google's internal tasks. No worries. > >> [2] https://github.com/googleprodkernel/linux-cc/commits/wip-tdx-gmem-conversions-hugetlb-2mept-v2 > >> > >> > However, if it's difficult for you, please feel free to let us know. > >> > > >> > Thanks > >> > Yan
