On Mon, 2023-06-26 at 18:20 +0000, Mingwei Zhang wrote: > Add the description of tdp_mmu_root_count into kvm_mmu_page description. > tdp_mmu_root_count is an atomic counter used only in TDP MMU. Its usage and > meaning is slightly different with root_counter in shadow MMU. Update the > doc. > > Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx> > --- > Documentation/virt/kvm/x86/mmu.rst | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/virt/kvm/x86/mmu.rst b/Documentation/virt/kvm/x86/mmu.rst > index 5cd6cd5e8926..97d695207e11 100644 > --- a/Documentation/virt/kvm/x86/mmu.rst > +++ b/Documentation/virt/kvm/x86/mmu.rst > @@ -231,6 +231,11 @@ Shadow pages contain the following information: > A counter keeping track of how many hardware registers (guest cr3 or > pdptrs) are now pointing at the page. While this counter is nonzero, the > page cannot be destroyed. See role.invalid. > + tdp_mmu_root_count: > + An atomic reference counter in TDP MMU root page that allows for parallel > + accesses. Accessing the page requires lifting the counter value. The > + initial value is set to 2 indicating one reference from vCPU and one > + from TDP MMU itself. Note this field is a union with root_count. > parent_ptes: > The reverse mapping for the pte/ptes pointing at this page's spt. If > parent_ptes bit 0 is zero, only one spte points at this page and > -- > 2.41.0.162.gfafddb0af9-goog > Reviewed-by: Kai Huang <kai.huang@xxxxxxxxx>
