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
