Re: [PATCH v18 00/18] KVM RISC-V Support

Greg Kroah-Hartman
2021-05-19T04:58:16Z

On Wed, May 19, 2021 at 09:05:35AM +0530, Anup Patel wrote:
> From: Anup Patel <anup@brainfault.org>
>
> This series adds initial KVM RISC-V support. Currently, we are able to boot
> Linux on RV64/RV32 Guest with multiple VCPUs.
>
> Key aspects of KVM RISC-V added by this series are:
> 1. No RISC-V specific KVM IOCTL
> 2. Minimal possible KVM world-switch which touches only GPRs and few CSRs
> 3. Both RV64 and RV32 host supported
> 4. Full Guest/VM switch is done via vcpu_get/vcpu_put infrastructure
> 5. KVM ONE_REG interface for VCPU register access from user-space
> 6. PLIC emulation is done in user-space
> 7. Timer and IPI emuation is done in-kernel
> 8. Both Sv39x4 and Sv48x4 supported for RV64 host
> 9. MMU notifiers supported
> 10. Generic dirtylog supported
> 11. FP lazy save/restore supported
> 12. SBI v0.1 emulation for KVM Guest available
> 13. Forward unhandled SBI calls to KVM userspace
> 14. Hugepage support for Guest/VM
> 15. IOEVENTFD support for Vhost
>
> Here's a brief TODO list which we will work upon after this series:
> 1. SBI v0.2 emulation in-kernel
> 2. SBI v0.2 hart state management emulation in-kernel
> 3. In-kernel PLIC emulation
> 4. ..... and more .....
>
> This series can be found in riscv_kvm_v18 branch at:
> https//github.com/avpatel/linux.git
>
> Our work-in-progress KVMTOOL RISC-V port can be found in riscv_v7 branch
> at: https//github.com/avpatel/kvmtool.git
>
> The QEMU RISC-V hypervisor emulation is done by Alistair and is available
> in master branch at: https://git.qemu.org/git/qemu.git
>
> To play around with KVM RISC-V, refer KVM RISC-V wiki at:
> https://github.com/kvm-riscv/howto/wiki
> https://github.com/kvm-riscv/howto/wiki/KVM-RISCV64-on-QEMU
> https://github.com/kvm-riscv/howto/wiki/KVM-RISCV64-on-Spike
>
> Changes since v17:
> - Rebased on Linux-5.13-rc2
> - Moved to new KVM MMU notifier APIs
> - Removed redundant kvm_arch_vcpu_uninit()
> - Moved KVM RISC-V sources to drivers/staging for compliance with
> Linux RISC-V patch acceptance policy

What is this new "patch acceptance policy" and what does it have to do
with drivers/staging?

What does drivers/staging/ have to do with this at all? Did anyone ask
the staging maintainer about this?

Not cool, and not something I'm about to take without some very good
reasons...

greg k-h