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    SubjectRe: [RFC PATCH v5 038/104] KVM: x86/mmu: Allow per-VM override of the TDP max page level
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    On Fri, 2022-04-01 at 14:08 +0000, Sean Christopherson wrote:
    > On Fri, Apr 01, 2022, Kai Huang wrote:
    > > On Fri, 2022-03-04 at 11:48 -0800, isaku.yamahata@intel.com wrote:
    > > > From: Sean Christopherson <sean.j.christopherson@intel.com>
    > > >
    > > > In the existing x86 KVM MMU code, there is already max_level member in
    > > > struct kvm_page_fault with KVM_MAX_HUGEPAGE_LEVEL initial value. The KVM
    > > > page fault handler denies page size larger than max_level.
    > > >
    > > > Add per-VM member to indicate the allowed maximum page size with
    > > > KVM_MAX_HUGEPAGE_LEVEL as default value and initialize max_level in struct
    > > > kvm_page_fault with it.
    > > >
    > > > For the guest TD, the set per-VM value for allows maximum page size to 4K
    > > > page size. Then only allowed page size is 4K. It means large page is
    > > > disabled.
    > >
    > > Do not support large page for TD is the reason that you want this change, but
    > > not the result. Please refine a little bit.
    >
    > Not supporting huge pages was fine for the PoC, but I'd prefer not to merge TDX
    > without support for huge pages. Has any work been put into enabling huge pages?
    > If so, what's the technical blocker? If not...

    Hi Sean,

    Is there any reason large page support must be included in the initial merge of
    TDX? Large page is more about performance improvement I think. Given this
    series is already very big, perhaps we can do it later.

    --
    Thanks,
    -Kai


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