Re: [PATCH 5/6] KVM: Documentation: Add the missing mmu_valid_gen into kvm_mmu_page

Huang, Kai
2023-06-22T08:45:42Z

On Sun, 2023-06-18 at 00:08 +0000, Mingwei Zhang wrote:
> Add mmu_valid_gen into kvm_mmu_page description. mmu_valid_gen is used in
> shadow MMU for fast zapping. Update the doc to reflect that.
>
> Signed-off-by: Mingwei Zhang <mizhang@google.com>
> ---
> Documentation/virt/kvm/x86/mmu.rst | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/Documentation/virt/kvm/x86/mmu.rst b/Documentation/virt/kvm/x86/mmu.rst
> index 3dce2426ad6d..0dbdb7fb8cc6 100644
> --- a/Documentation/virt/kvm/x86/mmu.rst
> +++ b/Documentation/virt/kvm/x86/mmu.rst
> @@ -208,6 +208,10 @@ Shadow pages contain the following information:
> The page is not backed by a guest page table, but its first entry
> points to one. This is set if NPT uses 5-level page tables (host
> CR4.LA57=1) and is shadowing L1's 4-level NPT (L1 CR4.LA57=1).
> + mmu_valid_gen:
> + Used by comparing against kvm->arch.mmu_valid_gen to check whether the
> + shadow page is obsolete thus a convenient variable for fast zapping.
> + Note that TDP MMU does not use mmu_valid_gen.
> gfn:
> Either the guest page table containing the translations shadowed by this
> page, or the base page frame for linear translations. See role.direct.

Reviewed-by: Kai Huang <kai.huang@intel.com>