This is the next iteration of implementing fd-based (instead of vma-based) memory for KVM guests. If you want the full background of why we are doing this, please go read the v10 cover letter[1]. The biggest change from v10 is to implement the backing storage in KVM itself, and expose it via a KVM ioctl() instead of a "generic" sycall. See link[2] for details on why we pivoted to a KVM-specific approach. Key word is "biggest". Relative to v10, there are many big changes. Highlights below (I can't remember everything that got changed at this point). Tagged RFC as there are a lot of empty changelogs, and a lot of missing documentation. And ideally, we'll have even more tests before merging. There are also several gaps/opens (to be discussed in tomorrow's PUCK). v11: - Test private<=>shared conversions *without* doing fallocate() - PUNCH_HOLE all memory between iterations of the conversion test so that KVM doesn't retain pages in the guest_memfd - Rename hugepage control to be a very generic ALLOW_HUGEPAGE, instead of giving it a THP or PMD specific name. - Fold in fixes from a lot of people (thank you!) - Zap SPTEs *before* updating attributes to ensure no weirdness, e.g. if KVM handles a page fault and looks at inconsistent attributes - Refactor MMU interaction with attributes updates to reuse much of KVM's framework for mmu_notifiers. [1] https://lore.kernel.org/all/20221202061347.1070246-1-chao.p.peng@xxxxxxxxxxxxxxx [2] https://lore.kernel.org/all/ZEM5Zq8oo+xnApW9@xxxxxxxxxx Ackerley Tng (1): KVM: selftests: Test KVM exit behavior for private memory/access Chao Peng (7): KVM: Use gfn instead of hva for mmu_notifier_retry KVM: Add KVM_EXIT_MEMORY_FAULT exit KVM: Introduce per-page memory attributes KVM: x86: Disallow hugepages when memory attributes are mixed KVM: x86/mmu: Handle page fault for private memory KVM: selftests: Add KVM_SET_USER_MEMORY_REGION2 helper KVM: selftests: Expand set_memory_region_test to validate guest_memfd() Sean Christopherson (18): KVM: Wrap kvm_gfn_range.pte in a per-action union KVM: Tweak kvm_hva_range and hva_handler_t to allow reusing for gfn ranges KVM: PPC: Drop dead code related to KVM_ARCH_WANT_MMU_NOTIFIER KVM: Convert KVM_ARCH_WANT_MMU_NOTIFIER to CONFIG_KVM_GENERIC_MMU_NOTIFIER KVM: Introduce KVM_SET_USER_MEMORY_REGION2 mm: Add AS_UNMOVABLE to mark mapping as completely unmovable security: Export security_inode_init_security_anon() for use by KVM KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory KVM: Add transparent hugepage support for dedicated guest memory KVM: Drop superfluous __KVM_VCPU_MULTIPLE_ADDRESS_SPACE macro KVM: Allow arch code to track number of memslot address spaces per VM KVM: x86: Add support for "protected VMs" that can utilize private memory KVM: selftests: Drop unused kvm_userspace_memory_region_find() helper KVM: selftests: Convert lib's mem regions to KVM_SET_USER_MEMORY_REGION2 KVM: selftests: Add support for creating private memslots KVM: selftests: Introduce VM "shape" to allow tests to specify the VM type KVM: selftests: Add GUEST_SYNC[1-6] macros for synchronizing more data KVM: selftests: Add basic selftest for guest_memfd() Vishal Annapurve (3): KVM: selftests: Add helpers to convert guest memory b/w private and shared KVM: selftests: Add helpers to do KVM_HC_MAP_GPA_RANGE hypercalls (x86) KVM: selftests: Add x86-only selftest for private memory conversions Documentation/virt/kvm/api.rst | 114 ++++ arch/arm64/include/asm/kvm_host.h | 2 - arch/arm64/kvm/Kconfig | 2 +- arch/arm64/kvm/mmu.c | 2 +- arch/mips/include/asm/kvm_host.h | 2 - arch/mips/kvm/Kconfig | 2 +- arch/mips/kvm/mmu.c | 2 +- arch/powerpc/include/asm/kvm_host.h | 2 - arch/powerpc/kvm/Kconfig | 8 +- arch/powerpc/kvm/book3s_hv.c | 2 +- arch/powerpc/kvm/powerpc.c | 5 +- arch/riscv/include/asm/kvm_host.h | 2 - arch/riscv/kvm/Kconfig | 2 +- arch/riscv/kvm/mmu.c | 2 +- arch/x86/include/asm/kvm_host.h | 17 +- arch/x86/include/uapi/asm/kvm.h | 3 + arch/x86/kvm/Kconfig | 14 +- arch/x86/kvm/debugfs.c | 2 +- arch/x86/kvm/mmu/mmu.c | 287 +++++++- arch/x86/kvm/mmu/mmu_internal.h | 4 + arch/x86/kvm/mmu/mmutrace.h | 1 + arch/x86/kvm/mmu/tdp_mmu.c | 8 +- arch/x86/kvm/vmx/vmx.c | 11 +- arch/x86/kvm/x86.c | 24 +- include/linux/kvm_host.h | 129 +++- include/linux/pagemap.h | 11 + include/uapi/linux/kvm.h | 50 ++ include/uapi/linux/magic.h | 1 + mm/compaction.c | 4 + mm/migrate.c | 2 + security/security.c | 1 + tools/testing/selftests/kvm/Makefile | 3 + tools/testing/selftests/kvm/dirty_log_test.c | 2 +- .../testing/selftests/kvm/guest_memfd_test.c | 114 ++++ .../selftests/kvm/include/kvm_util_base.h | 141 +++- .../testing/selftests/kvm/include/test_util.h | 5 + .../selftests/kvm/include/ucall_common.h | 12 + .../selftests/kvm/include/x86_64/processor.h | 15 + .../selftests/kvm/kvm_page_table_test.c | 2 +- tools/testing/selftests/kvm/lib/kvm_util.c | 230 ++++--- tools/testing/selftests/kvm/lib/memstress.c | 3 +- .../selftests/kvm/set_memory_region_test.c | 99 +++ .../kvm/x86_64/private_mem_conversions_test.c | 408 +++++++++++ .../kvm/x86_64/private_mem_kvm_exits_test.c | 115 ++++ .../kvm/x86_64/ucna_injection_test.c | 2 +- virt/kvm/Kconfig | 17 + virt/kvm/Makefile.kvm | 1 + virt/kvm/dirty_ring.c | 2 +- virt/kvm/guest_mem.c | 635 ++++++++++++++++++ virt/kvm/kvm_main.c | 384 +++++++++-- virt/kvm/kvm_mm.h | 38 ++ 51 files changed, 2700 insertions(+), 246 deletions(-) create mode 100644 tools/testing/selftests/kvm/guest_memfd_test.c create mode 100644 tools/testing/selftests/kvm/x86_64/private_mem_conversions_test.c create mode 100644 tools/testing/selftests/kvm/x86_64/private_mem_kvm_exits_test.c create mode 100644 virt/kvm/guest_mem.c base-commit: fdf0eaf11452d72945af31804e2a1048ee1b574c -- 2.41.0.255.g8b1d071c50-goog
