[PATCH Part2 v5 30/45] KVM: x86/mmu: Introduce kvm_mmu_map_tdp_page() for use by TDX and SNP
From: Brijesh Singh <hidden>
Date: 2021-08-20 16:04:38
Also in:
kvm, linux-coco, linux-mm, lkml
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Sean Christopherson <redacted> 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 <redacted> Signed-off-by: Isaku Yamahata <redacted> Signed-off-by: Brijesh Singh <redacted> --- arch/x86/kvm/mmu.h | 3 +++ arch/x86/kvm/mmu/mmu.c | 25 +++++++++++++++++++++++++ 2 files changed, 28 insertions(+)
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 83e6c6965f1e..af063188d073 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h@@ -127,6 +127,9 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, return vcpu->arch.mmu->page_fault(vcpu, cr2_or_gpa, err, prefault); } +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 5cbcbedcaaa6..a21e64ec048b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c@@ -3948,6 +3948,31 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, max_level, true, &pfn); } +kvm_pfn_t kvm_mmu_map_tdp_page(struct kvm_vcpu *vcpu, gpa_t gpa, + u32 error_code, int max_level) +{ + kvm_pfn_t pfn; + int r; + + 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 { + r = direct_page_fault(vcpu, gpa, error_code, false, max_level, + true, &pfn); + } while (r == RET_PF_RETRY && !is_error_noslot_pfn(pfn)); + return pfn; +} +EXPORT_SYMBOL_GPL(kvm_mmu_map_tdp_page); + static void nonpaging_init_context(struct kvm_mmu *context) { context->page_fault = nonpaging_page_fault;
--
2.17.1