From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Introduce a helper to directly (pun intended) fault-in a TDP page without having to go through the full page fault path. This allows SEV/TDX to pin pages before booting the guest, provides the resulting pfn to vendor code if should be needed in the future, and allows the RET_PF_* enums to stay in mmu.c where they belong. Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx> --- arch/x86/kvm/mmu.h | 3 +++ arch/x86/kvm/mmu/mmu.c | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index e9fbb2c8bbe2..0595891dd834 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -202,6 +202,9 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, return vcpu->arch.mmu->page_fault(vcpu, &fault); } +kvm_pfn_t kvm_mmu_map_tdp_page(struct kvm_vcpu *vcpu, gpa_t gpa, + u32 error_code, int max_level); + /* * Currently, we have two sorts of write-protection, a) the first one * write-protects guest page to sync the guest modification, b) another one is diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index b94e5e71653e..5f5da1a4e6be 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4134,6 +4134,44 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) return direct_page_fault(vcpu, fault); } +kvm_pfn_t kvm_mmu_map_tdp_page(struct kvm_vcpu *vcpu, gpa_t gpa, + u32 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, + .nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(), + }; + + if (mmu_topup_memory_caches(vcpu, false)) + return KVM_PFN_ERR_FAULT; + + /* + * Loop on the page fault path to handle the case where an mmu_notifier + * invalidation triggers RET_PF_RETRY. In the normal page fault path, + * KVM needs to resume the guest in case the invalidation changed any + * of the page fault properties, i.e. the gpa or error code. For this + * path, the gpa and error code are fixed by the caller, and the caller + * expects failure if and only if the page fault can't be fixed. + */ + do { + fault.max_level = max_level; + fault.req_level = PG_LEVEL_4K; + fault.goal_level = PG_LEVEL_4K; + r = direct_page_fault(vcpu, &fault); + } while (r == RET_PF_RETRY && !is_error_noslot_pfn(fault.pfn)); + return fault.pfn; +} +EXPORT_SYMBOL_GPL(kvm_mmu_map_tdp_page); + static void nonpaging_init_context(struct kvm_mmu *context) { context->page_fault = nonpaging_page_fault; -- 2.32.0