This series introduces a new ioctl KVM_TRANSLATE2, which expands on KVM_TRANSLATE. It is required to implement Hyper-V's HvTranslateVirtualAddress hyper-call as part of the ongoing effort to emulate HyperV's Virtual Secure Mode (VSM) within KVM and QEMU. The hyper- call requires several new KVM APIs, one of which is KVM_TRANSLATE2, which implements the core functionality of the hyper-call. The rest of the required functionality will be implemented in subsequent series. Other than translating guest virtual addresses, the ioctl allows the caller to control whether the access and dirty bits are set during the page walk. It also allows specifying an access mode instead of returning viable access modes, which enables setting the bits up to the level that caused a failure. Additionally, the ioctl provides more information about why the page walk failed, and which page table is responsible. This functionality is not available within KVM_TRANSLATE, and can't be added without breaking backwards compatiblity, thus a new ioctl is required. The ioctl was designed to facilitate as many other use cases as possible apart from VSM. The error codes were intentionally chosen to be broad enough to avoid exposing architecture specific details. Even though HvTranslateVirtualAddress only really needs one flag to set the accessed and dirty bits whenever possible, that was split into several flags so that future users can chose more gradually when these bits should be set. Furthermore, as much information as possible is provided to the caller. The patch series includes selftests for the ioctl, as well as fuzzy testing on random garbage guest page table entries. All previously passing KVM selftests and KVM unit tests still pass. Series overview: - 1: Document the new ioctl - 2-11: Update the page walker in preparation - 12-14: Implement the ioctl - 15: Implement testing This series, alongside the series by Nicolas Saenz Julienne [1] introducing the core building blocks for VSM and the accompanying QEMU implementation [2], is capable of booting Windows Server 2019. Both series are also available on GitHub [3]. [1] https://lore.kernel.org/linux-hyperv/20240609154945.55332-1-nsaenz@xxxxxxxxxx/ [2] https://github.com/vianpl/qemu/tree/vsm/next [3] https://github.com/vianpl/linux/tree/vsm/next Best, Nikolas Nikolas Wipper (15): KVM: Add API documentation for KVM_TRANSLATE2 KVM: x86/mmu: Abort page walk if permission checks fail KVM: x86/mmu: Introduce exception flag for unmapped GPAs KVM: x86/mmu: Store GPA in exception if applicable KVM: x86/mmu: Introduce flags parameter to page walker KVM: x86/mmu: Implement PWALK_SET_ACCESSED in page walker KVM: x86/mmu: Implement PWALK_SET_DIRTY in page walker KVM: x86/mmu: Implement PWALK_FORCE_SET_ACCESSED in page walker KVM: x86/mmu: Introduce status parameter to page walker KVM: x86/mmu: Implement PWALK_STATUS_READ_ONLY_PTE_GPA in page walker KVM: x86: Introduce generic gva to gpa translation function KVM: Introduce KVM_TRANSLATE2 KVM: Add KVM_TRANSLATE2 stub KVM: x86: Implement KVM_TRANSLATE2 KVM: selftests: Add test for KVM_TRANSLATE2 Documentation/virt/kvm/api.rst | 131 ++++++++ arch/x86/include/asm/kvm_host.h | 18 +- arch/x86/kvm/hyperv.c | 3 +- arch/x86/kvm/kvm_emulate.h | 8 + arch/x86/kvm/mmu.h | 10 +- arch/x86/kvm/mmu/mmu.c | 7 +- arch/x86/kvm/mmu/paging_tmpl.h | 80 +++-- arch/x86/kvm/x86.c | 123 ++++++- include/linux/kvm_host.h | 6 + include/uapi/linux/kvm.h | 33 ++ tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/x86_64/kvm_translate2.c | 310 ++++++++++++++++++ virt/kvm/kvm_main.c | 41 +++ 13 files changed, 724 insertions(+), 47 deletions(-) create mode 100644 tools/testing/selftests/kvm/x86_64/kvm_translate2.c -- 2.40.1 Amazon Web Services Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597
