Re: [RFC 0/5] LoongArch: KVM: Add separate vmid support

[Huacai Chen]

Hi, Bibo,

Any update on this?

Huacai

On Wed, Nov 13, 2024 at 11:17 AM Bibo Mao <maobibo@xxxxxxxxxxx> wrote:
>
> LoongArch KVM hypervisor supports two-level MMU, vpid index is used
> for stage1 MMU and vmid index is used for stage2 MMU.
>
> On 3A5000, vmid must be the same with vpid. On 3A6000 platform vmid
> may separate from vpid. There are such advantages if separate vpid
> is supported.
>   1. One VM uses one vmid, vCPUs on the same VM can share the same vmid.
>   2. If one vCPU switch between different physical CPU, old vmid can be
>      still usefil if old vmid is not expired
>   3. For remote tlb flush, only vmid need update and vpid need not
> update.
>
> Here add separate vmid feature support, vmid feature detecting method
> is not implemented since it depends on HW implementation, detecting
> method will be added when HW is ready.
>
> ---
> Bibo Mao (5):
>   LoongArch: KVM: Add vmid support for stage2 MMU
>   LoongArch: KVM: Add separate vmid feature support
>   LoongArch: KVM: implement vmid updating logic
>   LoongArch: KVM: Add remote tlb flushing support
>   LoongArch: KVM: Enable separate vmid feature
>
>  arch/loongarch/include/asm/kvm_host.h  | 10 ++++
>  arch/loongarch/include/asm/loongarch.h |  2 +
>  arch/loongarch/kernel/asm-offsets.c    |  1 +
>  arch/loongarch/kvm/main.c              | 76 ++++++++++++++++++++++++--
>  arch/loongarch/kvm/mmu.c               | 17 ++++++
>  arch/loongarch/kvm/switch.S            |  5 +-
>  arch/loongarch/kvm/tlb.c               | 19 ++++++-
>  arch/loongarch/kvm/vcpu.c              |  7 ++-
>  8 files changed, 128 insertions(+), 9 deletions(-)
>
>
> base-commit: 2d5404caa8c7bb5c4e0435f94b28834ae5456623
> --
> 2.39.3
>