On Mon, Dec 05, 2022, Vishal Annapurve wrote:
Introduce HAVE_KVM_PRIVATE_MEM_TESTING config to be able to test fd based @@ -272,13 +274,15 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, .rsvd = err & PFERR_RSVD_MASK, .user = err & PFERR_USER_MASK, .prefetch = prefetch,
.is_tdp = likely(vcpu->arch.mmu->page_fault == kvm_tdp_page_fault),
.is_tdp = is_tdp,.max_level = KVM_MAX_HUGEPAGE_LEVEL, .req_level = PG_LEVEL_4K, .goal_level = PG_LEVEL_4K,
.is_private = IS_ENABLED(CONFIG_HAVE_KVM_PRIVATE_MEM_TESTING) && is_tdp &&kvm_mem_is_private(vcpu->kvm, cr2_or_gpa >> PAGE_SHIFT),
After looking at the SNP+UPM series, I think we should forego a dedicated Kconfig for testing and instead add a new VM type for UPM-capable guests. The new type, e.g. KVM_X86_PROTECTED_VM, can then be used to leverage UPM for "legacy" SEV and SEV-ES guests, as well as for UPM-capable guests that don't utilize per-VM memory encryption, e.g. KVM selftests.
Carrying test-only behavior is obviously never ideal, and it would pretty much have to be mutually exclusive with "real" usage of UPM, otherwise the KVM logics gets unnecessarily complex.