| Message ID | 1a64f798b550dad9e096603e8dae3b6e8fb2fbd5.1705965635.git.isaku.yamahata@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM TDX basic feature support | expand |
On Mon, Jan 22, 2024 at 3:56 PM <isaku.yamahata@intel.com> wrote: > > From: Sean Christopherson <sean.j.christopherson@intel.com> > > Introduce a helper to directly (pun intended) fault-in a TDP page > without having to go through the full page fault path. This allows > TDX to get the resulting pfn and also allows the RET_PF_* enums to > stay in mmu.c where they belong. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > --- > v14 -> v15: > - Remove loop in kvm_mmu_map_tdp_page() and return error code based on > RET_FP_xxx value to avoid potential infinite loop. The caller should > loop on -EAGAIN instead now. > --- > arch/x86/kvm/mmu.h | 3 +++ > arch/x86/kvm/mmu/mmu.c | 57 ++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 60 insertions(+) > > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > index bad6a1e43a54..ebf91b605c37 100644 > --- a/arch/x86/kvm/mmu.h > +++ b/arch/x86/kvm/mmu.h > @@ -184,6 +184,9 @@ static inline void kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu, > __kvm_mmu_refresh_passthrough_bits(vcpu, mmu); > } > > +int kvm_mmu_map_tdp_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, > + int max_level); > + > /* > * Check if a given access (described through the I/D, W/R and U/S bits of a > * page fault error code pfec) causes a permission fault with the given PTE > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 7db152f46d82..26d215e85b76 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -4635,6 +4635,63 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) > return direct_page_fault(vcpu, fault); > } > > +int kvm_mmu_map_tdp_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, > + int max_level) > +{ > + int r; > + struct kvm_page_fault fault = (struct kvm_page_fault) { > + .addr = gpa, > + .error_code = error_code, > + .exec = error_code & PFERR_FETCH_MASK, > + .write = error_code & PFERR_WRITE_MASK, > + .present = error_code & PFERR_PRESENT_MASK, > + .rsvd = error_code & PFERR_RSVD_MASK, > + .user = error_code & PFERR_USER_MASK, > + .prefetch = false, > + .is_tdp = true, > + .is_private = error_code & PFERR_GUEST_ENC_MASK, > + .nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(vcpu->kvm), > + }; > + > + WARN_ON_ONCE(!vcpu->arch.mmu->root_role.direct); > + fault.gfn = gpa_to_gfn(fault.addr) & ~kvm_gfn_shared_mask(vcpu->kvm); > + fault.slot = kvm_vcpu_gfn_to_memslot(vcpu, fault.gfn); > + > + r = mmu_topup_memory_caches(vcpu, false); > + if (r) > + return r; > + > + fault.max_level = max_level; > + fault.req_level = PG_LEVEL_4K; > + fault.goal_level = PG_LEVEL_4K; > + > +#ifdef CONFIG_X86_64 > + if (tdp_mmu_enabled) > + r = kvm_tdp_mmu_page_fault(vcpu, &fault); > + else > +#endif > + r = direct_page_fault(vcpu, &fault); Are we ever going to hit the direct_page_fault case? I thought TDX only supported tdp_mmu? > + > + if (is_error_noslot_pfn(fault.pfn) || vcpu->kvm->vm_bugged) > + return -EFAULT; > + > + switch (r) { > + case RET_PF_RETRY: > + return -EAGAIN; > + > + case RET_PF_FIXED: > + case RET_PF_SPURIOUS: > + return 0; > + > + case RET_PF_CONTINUE: > + case RET_PF_EMULATE: > + case RET_PF_INVALID: > + default: > + return -EIO; > + } > +} > +EXPORT_SYMBOL_GPL(kvm_mmu_map_tdp_page); > + > static void nonpaging_init_context(struct kvm_mmu *context) > { > context->page_fault = nonpaging_page_fault; > -- > 2.25.1 >
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index bad6a1e43a54..ebf91b605c37 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -184,6 +184,9 @@ static inline void kvm_mmu_refresh_passthrough_bits(struct kvm_vcpu *vcpu, __kvm_mmu_refresh_passthrough_bits(vcpu, mmu); } +int kvm_mmu_map_tdp_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, + int max_level); + /* * Check if a given access (described through the I/D, W/R and U/S bits of a * page fault error code pfec) causes a permission fault with the given PTE diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 7db152f46d82..26d215e85b76 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4635,6 +4635,63 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) return direct_page_fault(vcpu, fault); } +int kvm_mmu_map_tdp_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, + int max_level) +{ + int r; + struct kvm_page_fault fault = (struct kvm_page_fault) { + .addr = gpa, + .error_code = error_code, + .exec = error_code & PFERR_FETCH_MASK, + .write = error_code & PFERR_WRITE_MASK, + .present = error_code & PFERR_PRESENT_MASK, + .rsvd = error_code & PFERR_RSVD_MASK, + .user = error_code & PFERR_USER_MASK, + .prefetch = false, + .is_tdp = true, + .is_private = error_code & PFERR_GUEST_ENC_MASK, + .nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(vcpu->kvm), + }; + + WARN_ON_ONCE(!vcpu->arch.mmu->root_role.direct); + fault.gfn = gpa_to_gfn(fault.addr) & ~kvm_gfn_shared_mask(vcpu->kvm); + fault.slot = kvm_vcpu_gfn_to_memslot(vcpu, fault.gfn); + + r = mmu_topup_memory_caches(vcpu, false); + if (r) + return r; + + fault.max_level = max_level; + fault.req_level = PG_LEVEL_4K; + fault.goal_level = PG_LEVEL_4K; + +#ifdef CONFIG_X86_64 + if (tdp_mmu_enabled) + r = kvm_tdp_mmu_page_fault(vcpu, &fault); + else +#endif + r = direct_page_fault(vcpu, &fault); + + if (is_error_noslot_pfn(fault.pfn) || vcpu->kvm->vm_bugged) + return -EFAULT; + + switch (r) { + case RET_PF_RETRY: + return -EAGAIN; + + case RET_PF_FIXED: + case RET_PF_SPURIOUS: + return 0; + + case RET_PF_CONTINUE: + case RET_PF_EMULATE: + case RET_PF_INVALID: + default: + return -EIO; + } +} +EXPORT_SYMBOL_GPL(kvm_mmu_map_tdp_page); + static void nonpaging_init_context(struct kvm_mmu *context) { context->page_fault = nonpaging_page_fault;