On Thu, May 30, 2024 at 11:07 PM Rick Edgecombe
<rick.p.edgecombe@xxxxxxxxx> wrote:
>
> From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
>
> Introduce a "mirror_pt" member to the kvm_mmu_page_role union to identify
> SPTEs associated with the mirrored EPT.
>
> The TDX module maintains the private half of the EPT mapped in the TD in
> its protected memory. KVM keeps a copy of the private GPAs in a mirrored
> EPT tree within host memory. This "mirror_pt" attribute enables vCPUs to
> find and get the root page of mirrored EPT from the MMU root list for a
> guest TD. This also allows KVM MMU code to detect changes in mirrored EPT
> according to the "mirror_pt" mmu page role and propagate the changes to
> the private EPT managed by TDX module.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
> ---
> TDX MMU Prep v2:
> - Rename private -> mirrored
>
> TDX MMU Prep:
> - Remove warning and NULL check in is_private_sptep() (Rick)
> - Update commit log (Yan)
>
> v19:
> - Fix is_private_sptep() when NULL case.
> - drop CONFIG_KVM_MMU_PRIVATE
> ---
> arch/x86/include/asm/kvm_host.h | 13 ++++++++++++-
> arch/x86/kvm/mmu/mmu_internal.h | 5 +++++
> arch/x86/kvm/mmu/spte.h | 5 +++++
> 3 files changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 250899a0239b..084f4708aff1 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -351,7 +351,8 @@ union kvm_mmu_page_role {
> unsigned ad_disabled:1;
> unsigned guest_mode:1;
> unsigned passthrough:1;
> - unsigned :5;
> + unsigned mirror_pt:1;
"is_mirror".
> + unsigned :4;
>
> /*
> * This is left at the top of the word so that
> @@ -363,6 +364,16 @@ union kvm_mmu_page_role {
> };
> };
>
> +static inline bool kvm_mmu_page_role_is_mirror(union kvm_mmu_page_role role)
> +{
> + return !!role.mirror_pt;
> +}
> +
> +static inline void kvm_mmu_page_role_set_mirrored(union kvm_mmu_page_role *role)
> +{
> + role->mirror_pt = 1;
> +}
Not needed, remove it.
> /*
> * kvm_mmu_extended_role complements kvm_mmu_page_role, tracking properties
> * relevant to the current MMU configuration. When loading CR0, CR4, or EFER,
> diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
> index faef40a561f9..6d82e389cd65 100644
> --- a/arch/x86/kvm/mmu/mmu_internal.h
> +++ b/arch/x86/kvm/mmu/mmu_internal.h
> @@ -157,6 +157,11 @@ static inline int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)
> return kvm_mmu_role_as_id(sp->role);
> }
>
> +static inline bool is_mirror_sp(const struct kvm_mmu_page *sp)
> +{
> + return kvm_mmu_page_role_is_mirror(sp->role);
> +}
e.g. "return sp->role.is_mirror".
> static inline void *kvm_mmu_mirrored_spt(struct kvm_mmu_page *sp)
> {
> return sp->mirrored_spt;
This one is also unnecessary BTW.
Otherwise looks good.
Paolo
> diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
> index 5dd5405fa07a..b3c065280ba1 100644
> --- a/arch/x86/kvm/mmu/spte.h
> +++ b/arch/x86/kvm/mmu/spte.h
> @@ -265,6 +265,11 @@ static inline struct kvm_mmu_page *root_to_sp(hpa_t root)
> return spte_to_child_sp(root);
> }
>
> +static inline bool is_mirror_sptep(u64 *sptep)
> +{
> + return is_mirror_sp(sptep_to_sp(sptep));
> +}
> +
> static inline bool is_mmio_spte(struct kvm *kvm, u64 spte)
> {
> return (spte & shadow_mmio_mask) == kvm->arch.shadow_mmio_value &&
> --
> 2.34.1
>
