[PATCH v10 00/59] KVM: arm64: ARMv8.3/8.4 Nested Virtualization support

Ganapatrao Kulkarni gankulkarni at os.amperecomputing.com
Tue Jun 27 23:45:55 PDT 2023


Hi Marc,


On 15-05-2023 11:00 pm, Marc Zyngier wrote:
> This is the 4th drop of NV support on arm64 for this year.
> 
> For the previous episodes, see [1].
> 
> What's changed:
> 
> - New framework to track system register traps that are reinjected in
>    guest EL2. It is expected to replace the discrete handling we have
>    enjoyed so far, which didn't scale at all. This has already fixed a
>    number of bugs that were hidden (a bunch of traps were never
>    forwarded...). Still a work in progress, but this is going in the
>    right direction.
> 
> - Allow the L1 hypervisor to have a S2 that has an input larger than
>    the L0 IPA space. This fixes a number of subtle issues, depending on
>    how the initial guest was created.
> 
> - Consequently, the patch series has gone longer again. Boo. But
>    hopefully some of it is easier to review...
> 

I am facing issue in booting NestedVM with V9 as well with 10 patchset.

I have tried V9/V10 on Ampere platform using kvmtool and I could boot
Guest-Hypervisor and then NestedVM without any issue.
However when I try to boot using QEMU(not using EDK2/EFI), 
Guest-Hypervisor is booted with Fedora 37 using virtio disk. From 
Guest-Hypervisor console(or ssh shell), If I try to boot NestedVM, boot 
hangs very early stage of the boot.

I did some debug using ftrace and it seems the Guest-Hypervisor is
getting very high rate of arch-timer interrupts,
due to that all CPU time is going on in serving the Guest-Hypervisor
and it is never going back to NestedVM.

I am using QEMU vanilla version v7.2.0 with top-up patches for NV [1]

[1] 
https://lore.kernel.org/all/20230227163718.62003-1-miguel.luis@oracle.com/

> [1] https://lore.kernel.org/r/20230405154008.3552854-1-maz@kernel.org
> 
> Andre Przywara (1):
>    KVM: arm64: nv: vgic: Allow userland to set VGIC maintenance IRQ
> 
> Christoffer Dall (5):
>    KVM: arm64: nv: Trap EL1 VM register accesses in virtual EL2
>    KVM: arm64: nv: Implement nested Stage-2 page table walk logic
>    KVM: arm64: nv: Unmap/flush shadow stage 2 page tables
>    KVM: arm64: nv: vgic: Emulate the HW bit in software
>    KVM: arm64: nv: Sync nested timer state with FEAT_NV2
> 
> Jintack Lim (7):
>    KVM: arm64: nv: Trap CPACR_EL1 access in virtual EL2
>    KVM: arm64: nv: Respect virtual HCR_EL2.TWX setting
>    KVM: arm64: nv: Respect virtual CPTR_EL2.{TFP,FPEN} settings
>    KVM: arm64: nv: Respect virtual HCR_EL2.{NV,TSC) settings
>    KVM: arm64: nv: Configure HCR_EL2 for nested virtualization
>    KVM: arm64: nv: Trap and emulate TLBI instructions from virtual EL2
>    KVM: arm64: nv: Nested GICv3 Support
> 
> Marc Zyngier (46):
>    KVM: arm64: Move VTCR_EL2 into struct s2_mmu
>    arm64: Add missing Set/Way CMO encodings
>    arm64: Add missing VA CMO encodings
>    arm64: Add missing ERXMISCx_EL1 encodings
>    arm64: Add missing DC ZVA/GVA/GZVA encodings
>    arm64: Add TLBI operation encodings
>    arm64: Add AT operation encodings
>    KVM: arm64: Add missing HCR_EL2 trap bits
>    KVM: arm64: nv: Add trap forwarding infrastructure
>    KVM: arm64: nv: Add trap forwarding for HCR_EL2
>    KVM: arm64: nv: Expose FEAT_EVT to nested guests
>    KVM: arm64: nv: Add trap forwarding for MDCR_EL2
>    KVM: arm64: nv: Add trap forwarding for CNTHCTL_EL2
>    KVM: arm64: nv: Add non-VHE-EL2->EL1 translation helpers
>    KVM: arm64: nv: Handle virtual EL2 registers in
>      vcpu_read/write_sys_reg()
>    KVM: arm64: nv: Handle SPSR_EL2 specially
>    KVM: arm64: nv: Handle HCR_EL2.E2H specially
>    KVM: arm64: nv: Save/Restore vEL2 sysregs
>    KVM: arm64: nv: Support multiple nested Stage-2 mmu structures
>    KVM: arm64: nv: Handle shadow stage 2 page faults
>    KVM: arm64: nv: Restrict S2 RD/WR permissions to match the guest's
>    KVM: arm64: nv: Set a handler for the system instruction traps
>    KVM: arm64: nv: Trap and emulate AT instructions from virtual EL2
>    KVM: arm64: nv: Fold guest's HCR_EL2 configuration into the host's
>    KVM: arm64: nv: Hide RAS from nested guests
>    KVM: arm64: nv: Add handling of EL2-specific timer registers
>    KVM: arm64: nv: Load timer before the GIC
>    KVM: arm64: nv: Don't load the GICv4 context on entering a nested
>      guest
>    KVM: arm64: nv: Implement maintenance interrupt forwarding
>    KVM: arm64: nv: Deal with broken VGIC on maintenance interrupt
>      delivery
>    KVM: arm64: nv: Allow userspace to request KVM_ARM_VCPU_NESTED_VIRT
>    KVM: arm64: nv: Add handling of FEAT_TTL TLB invalidation
>    KVM: arm64: nv: Invalidate TLBs based on shadow S2 TTL-like
>      information
>    KVM: arm64: nv: Tag shadow S2 entries with nested level
>    KVM: arm64: nv: Add include containing the VNCR_EL2 offsets
>    KVM: arm64: nv: Map VNCR-capable registers to a separate page
>    KVM: arm64: nv: Move nested vgic state into the sysreg file
>    KVM: arm64: Add FEAT_NV2 cpu feature
>    KVM: arm64: nv: Fold GICv3 host trapping requirements into guest setup
>    KVM: arm64: nv: Publish emulated timer interrupt state in the
>      in-memory state
>    KVM: arm64: nv: Allocate VNCR page when required
>    KVM: arm64: nv: Enable ARMv8.4-NV support
>    KVM: arm64: nv: Fast-track 'InHost' exception returns
>    KVM: arm64: nv: Fast-track EL1 TLBIs for VHE guests
>    KVM: arm64: nv: Use FEAT_ECV to trap access to EL0 timers
>    KVM: arm64: nv: Accelerate EL0 timer read accesses when FEAT_ECV is on
> 
>   .../virt/kvm/devices/arm-vgic-v3.rst          |  12 +-
>   arch/arm64/include/asm/esr.h                  |   1 +
>   arch/arm64/include/asm/kvm_arm.h              |  14 +
>   arch/arm64/include/asm/kvm_asm.h              |   4 +
>   arch/arm64/include/asm/kvm_emulate.h          |  93 +-
>   arch/arm64/include/asm/kvm_host.h             | 181 +++-
>   arch/arm64/include/asm/kvm_hyp.h              |   2 +
>   arch/arm64/include/asm/kvm_mmu.h              |  20 +-
>   arch/arm64/include/asm/kvm_nested.h           | 133 +++
>   arch/arm64/include/asm/stage2_pgtable.h       |   4 +-
>   arch/arm64/include/asm/sysreg.h               | 196 ++++
>   arch/arm64/include/asm/vncr_mapping.h         |  74 ++
>   arch/arm64/include/uapi/asm/kvm.h             |   1 +
>   arch/arm64/kernel/cpufeature.c                |  11 +
>   arch/arm64/kvm/Makefile                       |   4 +-
>   arch/arm64/kvm/arch_timer.c                   |  98 +-
>   arch/arm64/kvm/arm.c                          |  33 +-
>   arch/arm64/kvm/at.c                           | 219 ++++
>   arch/arm64/kvm/emulate-nested.c               | 934 ++++++++++++++++-
>   arch/arm64/kvm/handle_exit.c                  |  29 +-
>   arch/arm64/kvm/hyp/include/hyp/switch.h       |   8 +-
>   arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h    |   5 +-
>   arch/arm64/kvm/hyp/nvhe/mem_protect.c         |   8 +-
>   arch/arm64/kvm/hyp/nvhe/pkvm.c                |   4 +-
>   arch/arm64/kvm/hyp/nvhe/switch.c              |   2 +-
>   arch/arm64/kvm/hyp/nvhe/sysreg-sr.c           |   2 +-
>   arch/arm64/kvm/hyp/pgtable.c                  |   2 +-
>   arch/arm64/kvm/hyp/vgic-v3-sr.c               |   6 +-
>   arch/arm64/kvm/hyp/vhe/switch.c               | 206 +++-
>   arch/arm64/kvm/hyp/vhe/sysreg-sr.c            | 124 ++-
>   arch/arm64/kvm/hyp/vhe/tlb.c                  |  83 ++
>   arch/arm64/kvm/mmu.c                          | 255 ++++-
>   arch/arm64/kvm/nested.c                       | 799 ++++++++++++++-
>   arch/arm64/kvm/pkvm.c                         |   2 +-
>   arch/arm64/kvm/reset.c                        |   7 +
>   arch/arm64/kvm/sys_regs.c                     | 958 +++++++++++++++++-
>   arch/arm64/kvm/trace_arm.h                    |  19 +
>   arch/arm64/kvm/vgic/vgic-init.c               |  33 +
>   arch/arm64/kvm/vgic/vgic-kvm-device.c         |  32 +-
>   arch/arm64/kvm/vgic/vgic-v3-nested.c          | 248 +++++
>   arch/arm64/kvm/vgic/vgic-v3.c                 |  43 +-
>   arch/arm64/kvm/vgic/vgic.c                    |  29 +
>   arch/arm64/kvm/vgic/vgic.h                    |  10 +
>   arch/arm64/tools/cpucaps                      |   1 +
>   include/clocksource/arm_arch_timer.h          |   4 +
>   include/kvm/arm_arch_timer.h                  |   1 +
>   include/kvm/arm_vgic.h                        |  17 +
>   include/uapi/linux/kvm.h                      |   1 +
>   tools/arch/arm/include/uapi/asm/kvm.h         |   1 +
>   49 files changed, 4790 insertions(+), 183 deletions(-)
>   create mode 100644 arch/arm64/include/asm/vncr_mapping.h
>   create mode 100644 arch/arm64/kvm/at.c
>   create mode 100644 arch/arm64/kvm/vgic/vgic-v3-nested.c
> 

Thanks,
Ganapat



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