Re: [PATCH v3 0/3] LoongArch: KVM: Remove SW timer switch when vcpu is halt polling

[maobibo]

On 2023/11/13 下午10:36, Huacai Chen wrote:
> Hi, Bibo,
>
> Does this series have some relationship with the commit
> "LoongArch:LSVZ: set timer offset at first time once" in our internal
> repo?

No, it is not relative with internal repo. This patch is only 
optimization for timer save and restore. The internal repo is to set 
timestamp offset for VM.

I will post another patch for timestamp offset setting.

Regards
Bibo,

> Huacai
>
> On Fri, Nov 10, 2023 at 5:07 PM Bibo Mao <maobibo@xxxxxxxxxxx> wrote:
> > This patches removes SW timer switch during vcpu block stage. VM uses HW
> > timer rather than SW PV timer on LoongArch system, it can check pending
> > HW timer interrupt status directly, rather than switch to SW timer and
> > check injected SW timer interrupt.
> >
> > When SW timer is not used in vcpu halt-polling mode, the relative
> > SW timer handling before entering guest can be removed also. Timer
> > emulation is simpler than before, SW timer emuation is only used in vcpu
> > thread context switch.
> >
> > ---
> >
> > Changes in v3:
> >    Add kvm_arch_vcpu_runnable checking before kvm_vcpu_halt.
> >
> > Changes in v2:
> >    Add halt polling support for idle instruction emulation, using api
> > kvm_vcpu_halt rather than kvm_vcpu_block in function kvm_emu_idle.
> >
> > ---
> >
> > Bibo Mao (3):
> >    LoongArch: KVM: Remove SW timer switch when vcpu is halt polling
> >    LoongArch: KVM: Allow to access HW timer CSR registers always
> >    LoongArch: KVM: Remove kvm_acquire_timer before entering guest
> >
> >   arch/loongarch/include/asm/kvm_vcpu.h |  1 -
> >   arch/loongarch/kvm/exit.c             | 13 ++------
> >   arch/loongarch/kvm/main.c             |  1 -
> >   arch/loongarch/kvm/timer.c            | 47 +++++++--------------------
> >   arch/loongarch/kvm/vcpu.c             | 38 +++++-----------------
> >   5 files changed, 22 insertions(+), 78 deletions(-)
> >
> >
> > base-commit: 305230142ae0637213bf6e04f6d9f10bbcb74af8
> > --
> > 2.39.3