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| author | Lai Jiangshan <laijs@linux.alibaba.com> | 2021-11-24 15:20:51 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-12-08 12:25:13 +0300 |
| commit | bb3b394d35e80d7a58ce015191e4960a13f54ba5 (patch) | |
| tree | 5987cf2dbf34643fbeb82f8d101dda1d5409e6f1 /Documentation/virt | |
| parent | f8cd457f061d3ca79518f9061c4205590348a0a1 (diff) | |
| download | linux-bb3b394d35e80d7a58ce015191e4960a13f54ba5.tar.xz | |
KVM: X86: Rename gpte_is_8_bytes to has_4_byte_gpte and invert the direction
This bit is very close to mean "role.quadrant is not in use", except that
it is false also when the MMU is mapping guest physical addresses
directly. In that case, role.quadrant is indeed not in use, but there
are no guest PTEs at all.
Changing the name and direction of the bit removes the special case,
since a guest with paging disabled, or not considering guest paging
structures as is the case for two-dimensional paging, does not have
to deal with 4-byte guest PTEs.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211124122055.64424-10-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virt')
| -rw-r--r-- | Documentation/virt/kvm/mmu.rst | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/Documentation/virt/kvm/mmu.rst b/Documentation/virt/kvm/mmu.rst index f60f5488e121..5b1ebad24c77 100644 --- a/Documentation/virt/kvm/mmu.rst +++ b/Documentation/virt/kvm/mmu.rst @@ -161,7 +161,7 @@ Shadow pages contain the following information: If clear, this page corresponds to a guest page table denoted by the gfn field. role.quadrant: - When role.gpte_is_8_bytes=0, the guest uses 32-bit gptes while the host uses 64-bit + When role.has_4_byte_gpte=1, the guest uses 32-bit gptes while the host uses 64-bit sptes. That means a guest page table contains more ptes than the host, so multiple shadow pages are needed to shadow one guest page. For first-level shadow pages, role.quadrant can be 0 or 1 and denotes the @@ -177,9 +177,9 @@ Shadow pages contain the following information: The page is invalid and should not be used. It is a root page that is currently pinned (by a cpu hardware register pointing to it); once it is unpinned it will be destroyed. - role.gpte_is_8_bytes: - Reflects the size of the guest PTE for which the page is valid, i.e. '1' - if 64-bit gptes are in use, '0' if 32-bit gptes are in use. + role.has_4_byte_gpte: + Reflects the size of the guest PTE for which the page is valid, i.e. '0' + if direct map or 64-bit gptes are in use, '1' if 32-bit gptes are in use. role.efer_nx: Contains the value of efer.nx for which the page is valid. role.cr0_wp: |