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[RFC,v2,00/19] KVM RISC-V Support

Message ID 20190802074620.115029-1-anup.patel@wdc.com (mailing list archive)
Headers show
Series KVM RISC-V Support | expand

Message

Anup Patel Aug. 2, 2019, 7:46 a.m. UTC 
This series adds initial KVM RISC-V support. Currently, we are able to boot
RISC-V 64bit Linux Guests with multiple VCPUs.

Few key aspects of KVM RISC-V added by this series are:
1. Minimal possible KVM world-switch which touches only GPRs and few CSRs.
2. Full Guest/VM switch is done via vcpu_get/vcpu_put infrastructure.
3. KVM ONE_REG interface for VCPU register access from user-space.
4. PLIC emulation is done in user-space. In-kernel PLIC emulation, will
   be added in future.
5. Timer and IPI emuation is done in-kernel.
6. MMU notifiers supported.
7. FP lazy save/restore supported.
8. SBI v0.1 emulation for KVM Guest available.

Here's a brief TODO list which we will work upon after this series:
1. Handle trap from unpriv access in reading Guest instruction
2. Handle trap from unpriv access in SBI v0.1 emulation
3. Implement recursive stage2 page table programing
4. SBI v0.2 emulation in-kernel
5. SBI v0.2 hart hotplug emulation in-kernel
6. In-kernel PLIC emulation
7. ..... and more .....

This series is based upon KVM pre-patches sent by Atish earlier
(https://lkml.org/lkml/2019/7/31/1503) and it can be found in
riscv_kvm_v2 branch at:
https//github.com/avpatel/linux.git

Our work-in-progress KVMTOOL RISC-V port can be found in riscv_v1 branch at:
https//github.com/avpatel/kvmtool.git

We need OpenSBI with RISC-V hypervisor extension support which can be
found in hyp_ext_changes_v1 branch at:
https://github.com/riscv/opensbi.git

The QEMU RISC-V hypervisor emulation is done by Alistair and is available
in riscv-hyp-work.next branch at:
https://github.com/alistair23/qemu.git

To play around with KVM RISC-V, here are few reference commands:
1) To cross-compile KVMTOOL:
   $ make lkvm-static
2) To launch RISC-V Host Linux:
   $ qemu-system-riscv64 -monitor null -cpu rv64,h=true -M virt \
   -m 512M -display none -serial mon:stdio \
   -kernel opensbi/build/platform/qemu/virt/firmware/fw_jump.elf \
   -device loader,file=build-riscv64/arch/riscv/boot/Image,addr=0x80200000 \
   -initrd ./rootfs_kvm_riscv64.img \
   -append "root=/dev/ram rw console=ttyS0 earlycon=sbi"
3) To launch RISC-V Guest Linux with 9P rootfs:
   $ ./apps/lkvm-static run -m 128 -c2 --console serial \
   -p "console=ttyS0 earlycon=uart8250,mmio,0x3f8" -k ./apps/Image --debug
4) To launch RISC-V Guest Linux with initrd:
   $ ./apps/lkvm-static run -m 128 -c2 --console serial \
   -p "console=ttyS0 earlycon=uart8250,mmio,0x3f8" -k ./apps/Image \
   -i ./apps/rootfs.img --debug

Changes since v1:
- Fixed compile errors in building KVM RISC-V as module
- Removed unused kvm_riscv_halt_guest() and kvm_riscv_resume_guest()
- Set KVM_CAP_SYNC_MMU capability only after MMU notifiers are implemented
- Made vmid_version as unsigned long instead of atomic
- Renamed KVM_REQ_UPDATE_PGTBL to KVM_REQ_UPDATE_HGATP
- Renamed kvm_riscv_stage2_update_pgtbl() to kvm_riscv_stage2_update_hgatp()
- Configure HIDELEG and HEDELEG in kvm_arch_hardware_enable()
- Updated ONE_REG interface for CSR access to user-space
- Removed irqs_pending_lock and use atomic bitops instead
- Added separate patch for FP ONE_REG interface
- Added separate patch for updating MAINTAINERS file

Anup Patel (14):
  KVM: RISC-V: Add KVM_REG_RISCV for ONE_REG interface
  RISC-V: Add hypervisor extension related CSR defines
  RISC-V: Add initial skeletal KVM support
  RISC-V: KVM: Implement VCPU create, init and destroy functions
  RISC-V: KVM: Implement VCPU interrupts and requests handling
  RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls
  RISC-V: KVM: Implement VCPU world-switch
  RISC-V: KVM: Handle MMIO exits for VCPU
  RISC-V: KVM: Handle WFI exits for VCPU
  RISC-V: KVM: Implement VMID allocator
  RISC-V: KVM: Implement stage2 page table programming
  RISC-V: KVM: Implement MMU notifiers
  RISC-V: Enable VIRTIO drivers in RV64 and RV32 defconfig
  RISC-V: KVM: Add MAINTAINERS entry

Atish Patra (5):
  RISC-V: Export few kernel symbols
  RISC-V: KVM: Add timer functionality
  RISC-V: KVM: FP lazy save/restore
  RISC-V: KVM: Implement ONE REG interface for FP registers
  RISC-V: KVM: Add SBI v0.1 support

 MAINTAINERS                             |  10 +
 arch/riscv/Kconfig                      |   2 +
 arch/riscv/Makefile                     |   2 +
 arch/riscv/configs/defconfig            |  23 +-
 arch/riscv/configs/rv32_defconfig       |  13 +
 arch/riscv/include/asm/csr.h            |  58 ++
 arch/riscv/include/asm/kvm_host.h       | 228 ++++++
 arch/riscv/include/asm/kvm_vcpu_timer.h |  32 +
 arch/riscv/include/asm/pgtable-bits.h   |   1 +
 arch/riscv/include/uapi/asm/kvm.h       |  98 +++
 arch/riscv/kernel/asm-offsets.c         | 148 ++++
 arch/riscv/kernel/smp.c                 |   2 +-
 arch/riscv/kernel/time.c                |   1 +
 arch/riscv/kvm/Kconfig                  |  34 +
 arch/riscv/kvm/Makefile                 |  14 +
 arch/riscv/kvm/main.c                   |  84 +++
 arch/riscv/kvm/mmu.c                    | 904 +++++++++++++++++++++++
 arch/riscv/kvm/tlb.S                    |  43 ++
 arch/riscv/kvm/vcpu.c                   | 936 ++++++++++++++++++++++++
 arch/riscv/kvm/vcpu_exit.c              | 554 ++++++++++++++
 arch/riscv/kvm/vcpu_sbi.c               | 119 +++
 arch/riscv/kvm/vcpu_switch.S            | 368 ++++++++++
 arch/riscv/kvm/vcpu_timer.c             | 106 +++
 arch/riscv/kvm/vm.c                     |  86 +++
 arch/riscv/kvm/vmid.c                   | 124 ++++
 drivers/clocksource/timer-riscv.c       |   8 +
 include/clocksource/timer-riscv.h       |  16 +
 include/uapi/linux/kvm.h                |   1 +
 28 files changed, 4009 insertions(+), 6 deletions(-)
 create mode 100644 arch/riscv/include/asm/kvm_host.h
 create mode 100644 arch/riscv/include/asm/kvm_vcpu_timer.h
 create mode 100644 arch/riscv/include/uapi/asm/kvm.h
 create mode 100644 arch/riscv/kvm/Kconfig
 create mode 100644 arch/riscv/kvm/Makefile
 create mode 100644 arch/riscv/kvm/main.c
 create mode 100644 arch/riscv/kvm/mmu.c
 create mode 100644 arch/riscv/kvm/tlb.S
 create mode 100644 arch/riscv/kvm/vcpu.c
 create mode 100644 arch/riscv/kvm/vcpu_exit.c
 create mode 100644 arch/riscv/kvm/vcpu_sbi.c
 create mode 100644 arch/riscv/kvm/vcpu_switch.S
 create mode 100644 arch/riscv/kvm/vcpu_timer.c
 create mode 100644 arch/riscv/kvm/vm.c
 create mode 100644 arch/riscv/kvm/vmid.c
 create mode 100644 include/clocksource/timer-riscv.h

--
2.17.1

Comments

Paolo Bonzini Aug. 2, 2019, 9:22 a.m. UTC | #1 
On 02/08/19 09:46, Anup Patel wrote:
> This series adds initial KVM RISC-V support. Currently, we are able to boot
> RISC-V 64bit Linux Guests with multiple VCPUs.
> 
> Few key aspects of KVM RISC-V added by this series are:
> 1. Minimal possible KVM world-switch which touches only GPRs and few CSRs.
> 2. Full Guest/VM switch is done via vcpu_get/vcpu_put infrastructure.
> 3. KVM ONE_REG interface for VCPU register access from user-space.
> 4. PLIC emulation is done in user-space. In-kernel PLIC emulation, will
>    be added in future.
> 5. Timer and IPI emuation is done in-kernel.
> 6. MMU notifiers supported.
> 7. FP lazy save/restore supported.
> 8. SBI v0.1 emulation for KVM Guest available.
> 
> Here's a brief TODO list which we will work upon after this series:
> 1. Handle trap from unpriv access in reading Guest instruction
> 2. Handle trap from unpriv access in SBI v0.1 emulation
> 3. Implement recursive stage2 page table programing
> 4. SBI v0.2 emulation in-kernel
> 5. SBI v0.2 hart hotplug emulation in-kernel
> 6. In-kernel PLIC emulation
> 7. ..... and more .....
> 
> This series is based upon KVM pre-patches sent by Atish earlier
> (https://lkml.org/lkml/2019/7/31/1503) and it can be found in
> riscv_kvm_v2 branch at:
> https//github.com/avpatel/linux.git
> 
> Our work-in-progress KVMTOOL RISC-V port can be found in riscv_v1 branch at:
> https//github.com/avpatel/kvmtool.git
> 
> We need OpenSBI with RISC-V hypervisor extension support which can be
> found in hyp_ext_changes_v1 branch at:
> https://github.com/riscv/opensbi.git
> 
> The QEMU RISC-V hypervisor emulation is done by Alistair and is available
> in riscv-hyp-work.next branch at:
> https://github.com/alistair23/qemu.git
> 
> To play around with KVM RISC-V, here are few reference commands:
> 1) To cross-compile KVMTOOL:
>    $ make lkvm-static
> 2) To launch RISC-V Host Linux:
>    $ qemu-system-riscv64 -monitor null -cpu rv64,h=true -M virt \
>    -m 512M -display none -serial mon:stdio \
>    -kernel opensbi/build/platform/qemu/virt/firmware/fw_jump.elf \
>    -device loader,file=build-riscv64/arch/riscv/boot/Image,addr=0x80200000 \
>    -initrd ./rootfs_kvm_riscv64.img \
>    -append "root=/dev/ram rw console=ttyS0 earlycon=sbi"
> 3) To launch RISC-V Guest Linux with 9P rootfs:
>    $ ./apps/lkvm-static run -m 128 -c2 --console serial \
>    -p "console=ttyS0 earlycon=uart8250,mmio,0x3f8" -k ./apps/Image --debug
> 4) To launch RISC-V Guest Linux with initrd:
>    $ ./apps/lkvm-static run -m 128 -c2 --console serial \
>    -p "console=ttyS0 earlycon=uart8250,mmio,0x3f8" -k ./apps/Image \
>    -i ./apps/rootfs.img --debug

LGTM apart from the comments I've sent about locking---which was the
focus of my review this time through---and the bug on reading VSIP).

Please try to have your GPG key signed by some other Linux maintainers
so that you can use signed pull requests for RISC-V KVM.

Paolo

> Changes since v1:
> - Fixed compile errors in building KVM RISC-V as module
> - Removed unused kvm_riscv_halt_guest() and kvm_riscv_resume_guest()
> - Set KVM_CAP_SYNC_MMU capability only after MMU notifiers are implemented
> - Made vmid_version as unsigned long instead of atomic
> - Renamed KVM_REQ_UPDATE_PGTBL to KVM_REQ_UPDATE_HGATP
> - Renamed kvm_riscv_stage2_update_pgtbl() to kvm_riscv_stage2_update_hgatp()
> - Configure HIDELEG and HEDELEG in kvm_arch_hardware_enable()
> - Updated ONE_REG interface for CSR access to user-space
> - Removed irqs_pending_lock and use atomic bitops instead
> - Added separate patch for FP ONE_REG interface
> - Added separate patch for updating MAINTAINERS file
> 
> Anup Patel (14):
>   KVM: RISC-V: Add KVM_REG_RISCV for ONE_REG interface
>   RISC-V: Add hypervisor extension related CSR defines
>   RISC-V: Add initial skeletal KVM support
>   RISC-V: KVM: Implement VCPU create, init and destroy functions
>   RISC-V: KVM: Implement VCPU interrupts and requests handling
>   RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls
>   RISC-V: KVM: Implement VCPU world-switch
>   RISC-V: KVM: Handle MMIO exits for VCPU
>   RISC-V: KVM: Handle WFI exits for VCPU
>   RISC-V: KVM: Implement VMID allocator
>   RISC-V: KVM: Implement stage2 page table programming
>   RISC-V: KVM: Implement MMU notifiers
>   RISC-V: Enable VIRTIO drivers in RV64 and RV32 defconfig
>   RISC-V: KVM: Add MAINTAINERS entry
> 
> Atish Patra (5):
>   RISC-V: Export few kernel symbols
>   RISC-V: KVM: Add timer functionality
>   RISC-V: KVM: FP lazy save/restore
>   RISC-V: KVM: Implement ONE REG interface for FP registers
>   RISC-V: KVM: Add SBI v0.1 support
> 
>  MAINTAINERS                             |  10 +
>  arch/riscv/Kconfig                      |   2 +
>  arch/riscv/Makefile                     |   2 +
>  arch/riscv/configs/defconfig            |  23 +-
>  arch/riscv/configs/rv32_defconfig       |  13 +
>  arch/riscv/include/asm/csr.h            |  58 ++
>  arch/riscv/include/asm/kvm_host.h       | 228 ++++++
>  arch/riscv/include/asm/kvm_vcpu_timer.h |  32 +
>  arch/riscv/include/asm/pgtable-bits.h   |   1 +
>  arch/riscv/include/uapi/asm/kvm.h       |  98 +++
>  arch/riscv/kernel/asm-offsets.c         | 148 ++++
>  arch/riscv/kernel/smp.c                 |   2 +-
>  arch/riscv/kernel/time.c                |   1 +
>  arch/riscv/kvm/Kconfig                  |  34 +
>  arch/riscv/kvm/Makefile                 |  14 +
>  arch/riscv/kvm/main.c                   |  84 +++
>  arch/riscv/kvm/mmu.c                    | 904 +++++++++++++++++++++++
>  arch/riscv/kvm/tlb.S                    |  43 ++
>  arch/riscv/kvm/vcpu.c                   | 936 ++++++++++++++++++++++++
>  arch/riscv/kvm/vcpu_exit.c              | 554 ++++++++++++++
>  arch/riscv/kvm/vcpu_sbi.c               | 119 +++
>  arch/riscv/kvm/vcpu_switch.S            | 368 ++++++++++
>  arch/riscv/kvm/vcpu_timer.c             | 106 +++
>  arch/riscv/kvm/vm.c                     |  86 +++
>  arch/riscv/kvm/vmid.c                   | 124 ++++
>  drivers/clocksource/timer-riscv.c       |   8 +
>  include/clocksource/timer-riscv.h       |  16 +
>  include/uapi/linux/kvm.h                |   1 +
>  28 files changed, 4009 insertions(+), 6 deletions(-)
>  create mode 100644 arch/riscv/include/asm/kvm_host.h
>  create mode 100644 arch/riscv/include/asm/kvm_vcpu_timer.h
>  create mode 100644 arch/riscv/include/uapi/asm/kvm.h
>  create mode 100644 arch/riscv/kvm/Kconfig
>  create mode 100644 arch/riscv/kvm/Makefile
>  create mode 100644 arch/riscv/kvm/main.c
>  create mode 100644 arch/riscv/kvm/mmu.c
>  create mode 100644 arch/riscv/kvm/tlb.S
>  create mode 100644 arch/riscv/kvm/vcpu.c
>  create mode 100644 arch/riscv/kvm/vcpu_exit.c
>  create mode 100644 arch/riscv/kvm/vcpu_sbi.c
>  create mode 100644 arch/riscv/kvm/vcpu_switch.S
>  create mode 100644 arch/riscv/kvm/vcpu_timer.c
>  create mode 100644 arch/riscv/kvm/vm.c
>  create mode 100644 arch/riscv/kvm/vmid.c
>  create mode 100644 include/clocksource/timer-riscv.h
> 
> --
> 2.17.1
>