[PATCH RFC v4 00/15] Add riscv kvm accel support

Yifei Jiang jiangyifei at huawei.com
Thu Dec 3 07:46:48 EST 2020

This series adds both riscv32 and riscv64 kvm support, and implements
migration based on riscv. It is based on temporarily unaccepted kvm:
https://github.com/kvm-riscv/linux (lastest version v15).

This series depends on above pending changes which haven't yet been
accepted, so this QEMU patch series is treated as RFC patches until
that dependency has been dealt with.

Compared to RFC v3, the time scaling is supported in this series. The
new feature also requires the following patches:
[1] Bugfix in kvm v15
[2] kvm patches:
[PATCH RFC 0/3] Implement guest time scaling in RISC-V KVM

Several steps to use this:
1. Build emulation
$ ./configure --target-list=riscv64-softmmu
$ make -j$(nproc)

2. Build kernel

3. Build QEMU VM
Cross built in riscv toolchain.
$ PKG_CONFIG_LIBDIR=<toolchain pkgconfig path>
$ export PKG_CONFIG_SYSROOT_DIR=<toolchain sysroot path>
$ ./configure --target-list=riscv64-softmmu --enable-kvm \
--cross-prefix=riscv64-linux-gnu- --disable-libiscsi --disable-glusterfs \
--disable-libusb --disable-usb-redir --audio-drv-list= --disable-opengl \
$ make -j$(nproc)

4. Start emulation
$ ./qemu-system-riscv64 -M virt -m 4096M -cpu rv64,x-h=true -nographic \
        -name guest=riscv-hyp,debug-threads=on \
        -smp 4 \
        -bios ./fw_jump.bin \
        -kernel ./Image \
        -drive file=./hyp.img,format=raw,id=hd0 \
        -device virtio-blk-device,drive=hd0 \
        -append "root=/dev/vda rw console=ttyS0 earlycon=sbi"

5. Start kvm-acceled QEMU VM in emulation
$ ./qemu-system-riscv64 -M virt,accel=kvm -m 1024M -cpu host -nographic \
        -name guest=riscv-guset \
        -smp 2 \
        -bios none \
        -kernel ./Image \
        -drive file=./guest.img,format=raw,id=hd0 \
        -device virtio-blk-device,drive=hd0 \
        -append "root=/dev/vda rw console=ttyS0 earlycon=sbi"

Changes since RFC v3
- Rebase on QEMU v5.2.0-rc2 and kvm-riscv linux v15.
- Add time scaling support(New patches 13, 14 and 15).
- Fix the bug that guest vm can't reboot.

Changes since RFC v2
- Fix checkpatch error at target/riscv/sbi_ecall_interface.h.
- Add riscv migration support.

Changes since RFC v1
- Add separate SBI ecall interface header.
- Add riscv32 kvm accel support.

Yifei Jiang (15):
  linux-header: Update linux/kvm.h
  target/riscv: Add target/riscv/kvm.c to place the public kvm interface
  target/riscv: Implement function kvm_arch_init_vcpu
  target/riscv: Implement kvm_arch_get_registers
  target/riscv: Implement kvm_arch_put_registers
  target/riscv: Support start kernel directly by KVM
  hw/riscv: PLIC update external interrupt by KVM when kvm enabled
  target/riscv: Handle KVM_EXIT_RISCV_SBI exit
  target/riscv: Add host cpu type
  target/riscv: Add kvm_riscv_get/put_regs_timer
  target/riscv: Implement virtual time adjusting with vm state changing
  target/riscv: Support virtual time context synchronization
  target/riscv: Introduce dynamic time frequency for virt machine
  target/riscv: Synchronize vcpu's frequency with KVM
  target/riscv: Add time frequency migration support

 hw/intc/sifive_plic.c              |  31 +-
 hw/riscv/virt.c                    |  26 +-
 linux-headers/linux/kvm.h          |   8 +
 meson.build                        |   2 +
 target/riscv/cpu.c                 |  13 +
 target/riscv/cpu.h                 |  12 +
 target/riscv/kvm.c                 | 617 +++++++++++++++++++++++++++++
 target/riscv/kvm_riscv.h           |  25 ++
 target/riscv/machine.c             |  23 ++
 target/riscv/meson.build           |   1 +
 target/riscv/sbi_ecall_interface.h |  72 ++++
 11 files changed, 817 insertions(+), 13 deletions(-)
 create mode 100644 target/riscv/kvm.c
 create mode 100644 target/riscv/kvm_riscv.h
 create mode 100644 target/riscv/sbi_ecall_interface.h


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