This is the second part of nested virtualization patch series v2 - memory virtualization. You can find the first part (cpu virtualization) here [1]. For memory virtualization, the biggest issue is that we now have more than two stages of translation when running nested VMs while hardware only supports two stages. We choose to merge two stage-2 page tables (one from the guest hypervisor and the other from the host hypervisor) and create shadow stage-2 page tables, which have mappings from the nested VM’s physical addresses to the machine physical addresses. Stage-1 translation is done by the hardware as is done for the normal VMs. Patch 2 to 14 handle the shadow page table. Note that patch 1 is borrowed from Dave Martin's SVE patches [2], so that we can fake ID_AA64MMFR0_EL1 register value to the guest hypervisor in patch 2. The second half of the patch series (15 to 30) are to handle AT and TLBI instructions from the guest hypervisor. To get an idea of the AT instruction emulation, I'd recommend you start with patch 19. For TLBI instructions, see individual patches from patch 24 to 30. Note that we need to forward AT and TLBI instructions to the virtual EL2 if corresponding bits are set in the virtual HCR_EL2. This is mostly for recursive virtualization, and handled in patch 29 and 30. This patch set is tested on the FastModel with the v8.3 extension for arm64. I used a cubietruck for arm32 and was able to boot a VM without a problem. See the test setup here [3, 4]. This patch series is based on kvm/next d38338e and cpu virtualization patch set [1]. The whole patch series including cpu, memory, VGIC, and timer patches is available here: git@xxxxxxxxxx:columbia/nesting-pub.git rfc-v2-mem TODO: - Implement the reverse mapping feature to handle mmu notifiers more efficiently. v1-->v2: - Fixed a bug on arm32 (patch 5). - Removed most of TODOs. - Updated comments and commit messages. - Put change notes for each patches if any. [1] https://lists.cs.columbia.edu/pipermail/kvmarm/2017-July/026388.html [2] https://lists.cs.columbia.edu/pipermail/kvmarm/2017-August/026961.html [3] https://lists.cs.columbia.edu/pipermail/kvmarm/2017-July/026427.html [4] https://github.com/columbia/nesting-pub/wiki/Nested-virtualization-on-ARM-setup Christoffer Dall (12): KVM: arm/arm64: Remove unused params in mmu functions KVM: arm/arm64: Abstract stage-2 MMU state into a separate structure KVM: arm/arm64: Support mmu for the virtual EL2 execution KVM: arm64: Invalidate virtual EL2 TLB entries when needed KVM: arm64: Setup vttbr_el2 on each VM entry KVM: arm/arm64: Make mmu functions non-static KVM: arm/arm64: Unmap/flush shadow stage 2 page tables KVM: arm64: Implement nested Stage-2 page table walk logic KVM: arm/arm64: Handle shadow stage 2 page faults KVM: arm/arm64: Move kvm_is_write_fault to header file KVM: arm/arm64: Forward the guest hypervisor's stage 2 permission faults KVM: arm64: Fixes to toggle_cache for nesting Dave Martin (1): arm64: KVM: Hide unsupported AArch64 CPU features from guests Jintack Lim (18): KVM: arm64: Expose limited memory management support to the virtual EL2 KVM: arm/arm64: Manage mmus for nested VMs KVM: arm64: Move system register helper functions around KVM: arm64: Introduce sys_reg_desc.forward_trap KVM: arm64: Rework the system instruction emulation framework KVM: arm64: Enumerate AT and TLBI instructions to emulate KVM: arm64: Describe AT instruction emulation design KVM: arm64: Implement AT instruction handling KVM: arm64: Emulate AT S1E[01] instructions KVM: arm64: Emulate AT S1E2 instructions KVM: arm64: Emulate AT S12E[01] instructions KVM: arm64: Emulate TLBI ALLE2(IS) instruction KVM: arm64: Emulate TLBI VAE2* instrutions KVM: arm64: Emulate TLBI ALLE1(IS) KVM: arm64: Emulate TLBI VMALLS12E1(IS) instruction KVM: arm64: Emulate TLBI IPAS2E1* instructions KVM: arm64: Respect the virtual HCR_EL2.AT and NV setting KVM: arm64: Emulate TLBI instructions accesible from EL1 arch/arm/include/asm/kvm_asm.h | 7 +- arch/arm/include/asm/kvm_emulate.h | 19 + arch/arm/include/asm/kvm_host.h | 42 +- arch/arm/include/asm/kvm_mmu.h | 44 ++ arch/arm/kvm/hyp/switch.c | 3 +- arch/arm/kvm/hyp/tlb.c | 15 +- arch/arm64/include/asm/esr.h | 1 + arch/arm64/include/asm/kvm_arm.h | 5 + arch/arm64/include/asm/kvm_asm.h | 12 +- arch/arm64/include/asm/kvm_emulate.h | 29 ++ arch/arm64/include/asm/kvm_host.h | 45 +- arch/arm64/include/asm/kvm_mmu.h | 69 ++- arch/arm64/include/asm/sysreg.h | 56 +++ arch/arm64/kvm/Makefile | 1 + arch/arm64/kvm/context.c | 12 + arch/arm64/kvm/hyp/Makefile | 1 + arch/arm64/kvm/hyp/at.c | 131 +++++ arch/arm64/kvm/hyp/switch.c | 8 +- arch/arm64/kvm/hyp/tlb.c | 114 ++++- arch/arm64/kvm/mmu-nested.c | 441 +++++++++++++++++ arch/arm64/kvm/sys_regs.c | 907 ++++++++++++++++++++++++++++++----- arch/arm64/kvm/sys_regs.h | 6 + virt/kvm/arm/arm.c | 77 ++- virt/kvm/arm/mmio.c | 12 +- virt/kvm/arm/mmu.c | 361 +++++++++----- 25 files changed, 2084 insertions(+), 334 deletions(-) create mode 100644 arch/arm64/kvm/hyp/at.c create mode 100644 arch/arm64/kvm/mmu-nested.c -- 1.9.1
