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Message-ID: <0b2b367e-30c7-672e-f249-e4100c4dff5f@redhat.com>
Date:   Tue, 18 Jul 2023 15:50:31 +0800
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Subject: Re: [PATCH v6 06/11] KVM: arm64: Implement
 __kvm_tlb_flush_vmid_range()
Content-Language: en-US
To:     Raghavendra Rao Ananta <rananta@google.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Marc Zyngier <maz@kernel.org>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        Zenghui Yu <yuzenghui@huawei.com>,
        Anup Patel <anup@brainfault.org>,
        Atish Patra <atishp@atishpatra.org>,
        Jing Zhang <jingzhangos@google.com>,
        Colton Lewis <coltonlewis@google.com>,
        David Matlack <dmatlack@google.com>,
        linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev,
        linux-mips@vger.kernel.org, kvm-riscv@lists.infradead.org,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, Gavin Shan <gshan@redhat.com>
References: <20230715005405.3689586-1-rananta@google.com>
 <20230715005405.3689586-7-rananta@google.com>
From:   Shaoqin Huang <shahuang@redhat.com>
In-Reply-To: <20230715005405.3689586-7-rananta@google.com>
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Precedence: bulk

Hi Raghavendra,

On 7/15/23 08:54, Raghavendra Rao Ananta wrote:
> Define  __kvm_tlb_flush_vmid_range() (for VHE and nVHE)
> to flush a range of stage-2 page-tables using IPA in one go.
> If the system supports FEAT_TLBIRANGE, the following patches
> would conviniently replace global TLBI such as vmalls12e1is
> in the map, unmap, and dirty-logging paths with ripas2e1is
> instead.
> 
> Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> ---
>   arch/arm64/include/asm/kvm_asm.h   |  3 +++
>   arch/arm64/kvm/hyp/nvhe/hyp-main.c | 11 +++++++++++
>   arch/arm64/kvm/hyp/nvhe/tlb.c      | 30 ++++++++++++++++++++++++++++++
>   arch/arm64/kvm/hyp/vhe/tlb.c       | 23 +++++++++++++++++++++++
>   4 files changed, 67 insertions(+)
> 
> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
> index 7d170aaa2db4..2c27cb8cf442 100644
> --- a/arch/arm64/include/asm/kvm_asm.h
> +++ b/arch/arm64/include/asm/kvm_asm.h
> @@ -70,6 +70,7 @@ enum __kvm_host_smccc_func {
>   	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
>   	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
>   	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
> +	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
>   	__KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
>   	__KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
>   	__KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr,
> @@ -229,6 +230,8 @@ extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
>   extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
>   					 phys_addr_t ipa,
>   					 int level);
> +extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> +					phys_addr_t start, unsigned long pages);
>   extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
>   
>   extern void __kvm_timer_set_cntvoff(u64 cntvoff);
> diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> index a169c619db60..857d9bc04fd4 100644
> --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> @@ -135,6 +135,16 @@ static void handle___kvm_tlb_flush_vmid_ipa_nsh(struct kvm_cpu_context *host_ctx
>   	__kvm_tlb_flush_vmid_ipa_nsh(kern_hyp_va(mmu), ipa, level);
>   }
>   
> +static void
> +handle___kvm_tlb_flush_vmid_range(struct kvm_cpu_context *host_ctxt)
> +{
> +	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
> +	DECLARE_REG(phys_addr_t, start, host_ctxt, 2);
> +	DECLARE_REG(unsigned long, pages, host_ctxt, 3);
> +
> +	__kvm_tlb_flush_vmid_range(kern_hyp_va(mmu), start, pages);
> +}
> +
>   static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
>   {
>   	DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
> @@ -327,6 +337,7 @@ static const hcall_t host_hcall[] = {
>   	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
>   	HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa_nsh),
>   	HANDLE_FUNC(__kvm_tlb_flush_vmid),
> +	HANDLE_FUNC(__kvm_tlb_flush_vmid_range),
>   	HANDLE_FUNC(__kvm_flush_cpu_context),
>   	HANDLE_FUNC(__kvm_timer_set_cntvoff),
>   	HANDLE_FUNC(__vgic_v3_read_vmcr),
> diff --git a/arch/arm64/kvm/hyp/nvhe/tlb.c b/arch/arm64/kvm/hyp/nvhe/tlb.c
> index b9991bbd8e3f..09347111c2cd 100644
> --- a/arch/arm64/kvm/hyp/nvhe/tlb.c
> +++ b/arch/arm64/kvm/hyp/nvhe/tlb.c
> @@ -182,6 +182,36 @@ void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
>   	__tlb_switch_to_host(&cxt);
>   }
>   
> +void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> +				phys_addr_t start, unsigned long pages)
> +{
> +	struct tlb_inv_context cxt;
> +	unsigned long stride;
> +
> +	/*
> +	 * Since the range of addresses may not be mapped at
> +	 * the same level, assume the worst case as PAGE_SIZE
> +	 */
> +	stride = PAGE_SIZE;
> +	start = round_down(start, stride);
> +
> +	/* Switch to requested VMID */
> +	__tlb_switch_to_guest(mmu, &cxt, false);
> +
> +	__flush_tlb_range_op(ipas2e1is, start, pages, stride, 0, 0, false);
> +
> +	dsb(ish);
> +	__tlbi(vmalle1is);
> +	dsb(ish);
> +	isb();
> +
> +	/* See the comment in __kvm_tlb_flush_vmid_ipa() */
> +	if (icache_is_vpipt())
> +		icache_inval_all_pou();
> +
> +	__tlb_switch_to_host(&cxt);
> +}
> +
>   void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu)
>   {
>   	struct tlb_inv_context cxt;
> diff --git a/arch/arm64/kvm/hyp/vhe/tlb.c b/arch/arm64/kvm/hyp/vhe/tlb.c
> index e69da550cdc5..4ed8a1786812 100644
> --- a/arch/arm64/kvm/hyp/vhe/tlb.c
> +++ b/arch/arm64/kvm/hyp/vhe/tlb.c
> @@ -138,6 +138,29 @@ void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
>   	dsb(nsh);
>   	__tlbi(vmalle1);
>   	dsb(nsh);
> +
> +	__tlb_switch_to_host(&cxt);
> +}
> +
> +void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
> +				phys_addr_t start, unsigned long pages)
> +{
> +	struct tlb_inv_context cxt;
> +	unsigned long stride;
> +
> +	/*
> +	 * Since the range of addresses may not be mapped at
> +	 * the same level, assume the worst case as PAGE_SIZE
> +	 */
> +	stride = PAGE_SIZE;
> +	start = round_down(start, stride);
> +

Is there lack of switch VMID to guest?
	__tlb_switch_to_guest(mmu, &cxt, false);

Thanks,
Shaoqin

> +	dsb(ishst);
> +	__flush_tlb_range_op(ipas2e1is, start, pages, stride, 0, 0, false);
> +
> +	dsb(ish);
> +	__tlbi(vmalle1is);
> +	dsb(ish);
>   	isb();
>   
>   	__tlb_switch_to_host(&cxt);

-- 
Shaoqin