| Message ID | 20230626182016.4127366-7-mizhang@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Update document description for kvm_mmu_page and kvm_mmu_page_role | expand |
On Mon, 2023-06-26 at 18:20 +0000, Mingwei Zhang wrote: > Add the description for tdp_mmu_page into kvm_mmu_page description. > tdp_mmu_page is a field to differentiate shadow pages from TDP MMU and > non-TDP MMU. When TDP MMU is enabled, sp->tdp_mmu_page=1 indicates a shadow > page for L1, while sp->tdp_mmu_page=0 indicates a shadow page for an L2. > When TDP MMU is disabled, sp->tdp_mmu_page is always 0. So update the doc > to reflect the information. > > Signed-off-by: Mingwei Zhang <mizhang@google.com> > --- > Documentation/virt/kvm/x86/mmu.rst | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/Documentation/virt/kvm/x86/mmu.rst b/Documentation/virt/kvm/x86/mmu.rst > index cc4bd190c93d..678dc0260a54 100644 > --- a/Documentation/virt/kvm/x86/mmu.rst > +++ b/Documentation/virt/kvm/x86/mmu.rst > @@ -278,6 +278,8 @@ Shadow pages contain the following information: > since the last time the page table was actually used; if emulation > is triggered too frequently on this page, KVM will unmap the page > to avoid emulation in the future. > + tdp_mmu_page: > + Is 1 if the shadow page is a TDP MMU page. > > Reverse map > =========== > -- > 2.41.0.162.gfafddb0af9-goog > Reviewed-by: Kai Huang <kai.huang@intel.com>
On Mon, Jun 26, 2023, Mingwei Zhang wrote: > Add the description for tdp_mmu_page into kvm_mmu_page description. > tdp_mmu_page is a field to differentiate shadow pages from TDP MMU and > non-TDP MMU. When TDP MMU is enabled, sp->tdp_mmu_page=1 indicates a shadow > page for L1, while sp->tdp_mmu_page=0 indicates a shadow page for an L2. > When TDP MMU is disabled, sp->tdp_mmu_page is always 0. So update the doc > to reflect the information. > > Signed-off-by: Mingwei Zhang <mizhang@google.com> > --- > Documentation/virt/kvm/x86/mmu.rst | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/Documentation/virt/kvm/x86/mmu.rst b/Documentation/virt/kvm/x86/mmu.rst > index cc4bd190c93d..678dc0260a54 100644 > --- a/Documentation/virt/kvm/x86/mmu.rst > +++ b/Documentation/virt/kvm/x86/mmu.rst > @@ -278,6 +278,8 @@ Shadow pages contain the following information: > since the last time the page table was actually used; if emulation > is triggered too frequently on this page, KVM will unmap the page > to avoid emulation in the future. > + tdp_mmu_page: > + Is 1 if the shadow page is a TDP MMU page. Maybe add a short blurb explaining that it's used for control flow when starting from a common entry point? E.g. walking page tables given a root, and walking lists that can hold both shadow MMU and TDP MMU pages.
On Tue, Jun 27, 2023, Sean Christopherson wrote: > On Mon, Jun 26, 2023, Mingwei Zhang wrote: > > Add the description for tdp_mmu_page into kvm_mmu_page description. > > tdp_mmu_page is a field to differentiate shadow pages from TDP MMU and > > non-TDP MMU. When TDP MMU is enabled, sp->tdp_mmu_page=1 indicates a shadow > > page for L1, while sp->tdp_mmu_page=0 indicates a shadow page for an L2. > > When TDP MMU is disabled, sp->tdp_mmu_page is always 0. So update the doc > > to reflect the information. > > > > Signed-off-by: Mingwei Zhang <mizhang@google.com> > > --- > > Documentation/virt/kvm/x86/mmu.rst | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/Documentation/virt/kvm/x86/mmu.rst b/Documentation/virt/kvm/x86/mmu.rst > > index cc4bd190c93d..678dc0260a54 100644 > > --- a/Documentation/virt/kvm/x86/mmu.rst > > +++ b/Documentation/virt/kvm/x86/mmu.rst > > @@ -278,6 +278,8 @@ Shadow pages contain the following information: > > since the last time the page table was actually used; if emulation > > is triggered too frequently on this page, KVM will unmap the page > > to avoid emulation in the future. > > + tdp_mmu_page: > > + Is 1 if the shadow page is a TDP MMU page. > > Maybe add a short blurb explaining that it's used for control flow when starting > from a common entry point? E.g. walking page tables given a root, and walking > lists that can hold both shadow MMU and TDP MMU pages. will do. Thanks.
diff --git a/Documentation/virt/kvm/x86/mmu.rst b/Documentation/virt/kvm/x86/mmu.rst index cc4bd190c93d..678dc0260a54 100644 --- a/Documentation/virt/kvm/x86/mmu.rst +++ b/Documentation/virt/kvm/x86/mmu.rst @@ -278,6 +278,8 @@ Shadow pages contain the following information: since the last time the page table was actually used; if emulation is triggered too frequently on this page, KVM will unmap the page to avoid emulation in the future. + tdp_mmu_page: + Is 1 if the shadow page is a TDP MMU page. Reverse map ===========
Add the description for tdp_mmu_page into kvm_mmu_page description. tdp_mmu_page is a field to differentiate shadow pages from TDP MMU and non-TDP MMU. When TDP MMU is enabled, sp->tdp_mmu_page=1 indicates a shadow page for L1, while sp->tdp_mmu_page=0 indicates a shadow page for an L2. When TDP MMU is disabled, sp->tdp_mmu_page is always 0. So update the doc to reflect the information. Signed-off-by: Mingwei Zhang <mizhang@google.com> --- Documentation/virt/kvm/x86/mmu.rst | 2 ++ 1 file changed, 2 insertions(+)