[PATCH v4 0/5] Add SBI v0.2 support for KVM

[Atish Patra]

The Supervisor Binary Interface(SBI) specification[1] now defines a
base extension that provides extendability to add future extensions
while maintaining backward compatibility with previous versions.
The new version is defined as 0.2 and older version is marked as 0.1.

This series adds following features to RISC-V Linux KVM.
1. Adds support for SBI v0.2 in KVM
2. SBI Hart state management extension (HSM) in KVM
3. Ordered booting of guest vcpus in guest Linux

This series is based on base KVM series which is already part of the kvm-next[2]. 

Guest kernel needs to also support SBI v0.2 and HSM extension in Kernel
to boot multiple vcpus. Linux kernel supports both starting v5.7.
In absense of that, guest can only boot 1 vcpu.

Changes from v3->v4:
1. Fixed the commit text title.
2. Removed a redundant memory barrier from patch 4.
3. Replaced preempt_enable/disable with get_cpu/put_cpu.
4. Renamed the exixting implementation as v01 instead of legacy.

Changes from v2->v3:
1. Rebased on the latest merged kvm series.
2. Dropped the reset extension patch because reset extension is not merged in kernel. 
However, my tree[3] still contains it in case anybody wants to test it.

Changes from v1->v2:
1. Sent the patch 1 separately as it can merged independently.
2. Added Reset extension functionality.

Tested on Qemu and Rocket core FPGA.

[1] https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc
[3] https://github.com/atishp04/linux/tree/kvm_sbi_v03_reset
[4] https://github.com/atishp04/linux/tree/kvm_sbi_v03

Atish Patra (5):
RISC-V: KVM: Mark the existing SBI implementation as v01
RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own file
RISC-V: KVM: Add SBI v0.2 base extension
RISC-V: KVM: Add v0.1 replacement SBI extensions defined in v02
RISC-V: KVM: Add SBI HSM extension in KVM

arch/riscv/include/asm/kvm_vcpu_sbi.h |  33 +++++
arch/riscv/include/asm/sbi.h          |   9 ++
arch/riscv/kvm/Makefile               |   4 +
arch/riscv/kvm/vcpu.c                 |  23 +++
arch/riscv/kvm/vcpu_sbi.c             | 206 ++++++++++++--------------
arch/riscv/kvm/vcpu_sbi_base.c        |  73 +++++++++
arch/riscv/kvm/vcpu_sbi_hsm.c         | 107 +++++++++++++
arch/riscv/kvm/vcpu_sbi_replace.c     | 136 +++++++++++++++++
arch/riscv/kvm/vcpu_sbi_v01.c         | 129 ++++++++++++++++
9 files changed, 609 insertions(+), 111 deletions(-)
create mode 100644 arch/riscv/include/asm/kvm_vcpu_sbi.h
create mode 100644 arch/riscv/kvm/vcpu_sbi_base.c
create mode 100644 arch/riscv/kvm/vcpu_sbi_hsm.c
create mode 100644 arch/riscv/kvm/vcpu_sbi_replace.c
create mode 100644 arch/riscv/kvm/vcpu_sbi_v01.c

--
2.31.1