Re: [PATCH V5 14/15] KVM: MIPS: Enable KVM support for Loongson-3

From: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
To: Huacai Chen <chenhc@lemote.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	kvm@vger.kernel.org, linux-mips@vger.kernel.org,
	Fuxin Zhang <zhangfx@lemote.com>,
	Huacai Chen <chenhuacai@gmail.com>,
	Jiaxun Yang <jiaxun.yang@flygoat.com>
Subject: Re: [PATCH V5 14/15] KVM: MIPS: Enable KVM support for Loongson-3
Date: Thu, 14 May 2020 09:46:39 +0200	[thread overview]
Message-ID: <CAHiYmc5Pd+QGGeVCtmFeGYCCGEuSmS7jBrvGREyBtZ=nMxqt7g@mail.gmail.com> (raw)
In-Reply-To: <1589359366-1669-15-git-send-email-chenhc@lemote.com>

сре, 13. мај 2020. у 10:48 Huacai Chen <chenhc@lemote.com> је написао/ла:
>
> This patch enable KVM support for Loongson-3 by selecting HAVE_KVM, but
> only enable KVM/VZ on Loongson-3A R4+ (because VZ of early processors
> are incomplete). Besides, Loongson-3 support SMP guests, so we clear the
> linked load bit of LLAddr in kvm_vz_vcpu_load() if the guest has more
> than one VCPUs.
>
> Signed-off-by: Huacai Chen <chenhc@lemote.com>
> Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---

Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>

>  arch/mips/Kconfig            | 1 +
>  arch/mips/kernel/cpu-probe.c | 1 +
>  arch/mips/kvm/vz.c           | 2 +-
>  3 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index ce1aacc..3a15f2b 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -1405,6 +1405,7 @@ config CPU_LOONGSON64
>         select MIPS_L1_CACHE_SHIFT_6
>         select GPIOLIB
>         select SWIOTLB
> +       select HAVE_KVM
>         help
>                 The Loongson GSx64(GS264/GS464/GS464E/GS464V) series of processor
>                 cores implements the MIPS64R2 instruction set with many extensions,
> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
> index 319c250..415fbd2 100644
> --- a/arch/mips/kernel/cpu-probe.c
> +++ b/arch/mips/kernel/cpu-probe.c
> @@ -2008,6 +2008,7 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
>                 c->writecombine = _CACHE_UNCACHED_ACCELERATED;
>                 c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
>                         MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2);
> +               c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is incomplete */
>                 break;
>         case PRID_IMP_LOONGSON_64G:
>                 c->cputype = CPU_LOONGSON64;
> diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
> index 73701c3..dc753d0 100644
> --- a/arch/mips/kvm/vz.c
> +++ b/arch/mips/kvm/vz.c
> @@ -2697,7 +2697,7 @@ static int kvm_vz_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
>          * prevents a SC on the next VCPU from succeeding by matching a LL on
>          * the previous VCPU.
>          */
> -       if (cpu_guest_has_rw_llb)
> +       if (vcpu->kvm->created_vcpus > 1)
>                 write_gc0_lladdr(0);
>
>         return 0;
> --
> 2.7.0
>