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From: Alexandru Elisei <alexandru.elisei@arm.com>
To: Marc Zyngier <maz@kernel.org>,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: Will Deacon <will@kernel.org>, kernel-team@android.com
Subject: Re: [PATCH 2/8] KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation
Date: Mon, 2 Nov 2020 13:30:21 +0000	[thread overview]
Message-ID: <4ba97fdf-3b62-a414-2f34-ee7c3fe22808@arm.com> (raw)
In-Reply-To: <20201026095116.72051-3-maz@kernel.org>

Hi Marc,

On 10/26/20 9:51 AM, Marc Zyngier wrote:
> The new calling convention says that pointers coming from the SMCCC
> interface are turned into their HYP version in the host HVC handler.
> However, there is still a stray kern_hyp_va() in the TLB invalidation
> code, which could result in a corrupted pointer.
>
> Drop the spurious conversion.
>
> Fixes: a071261d9318 ("KVM: arm64: nVHE: Fix pointers during SMCCC convertion")
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
>  arch/arm64/kvm/hyp/nvhe/tlb.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/hyp/nvhe/tlb.c b/arch/arm64/kvm/hyp/nvhe/tlb.c
> index 39ca71ab8866..fbde89a2c6e8 100644
> --- a/arch/arm64/kvm/hyp/nvhe/tlb.c
> +++ b/arch/arm64/kvm/hyp/nvhe/tlb.c
> @@ -128,7 +128,6 @@ void __kvm_tlb_flush_local_vmid(struct kvm_s2_mmu *mmu)
>  	struct tlb_inv_context cxt;
>  
>  	/* Switch to requested VMID */
> -	mmu = kern_hyp_va(mmu);
>  	__tlb_switch_to_guest(mmu, &cxt);
>  
>  	__tlbi(vmalle1);

Looks fine to me, the function handle_host_hcall() already does the required
transformation when handling the __kvm_tlb_flush_local_vmid function id:

case KVM_HOST_SMCCC_FUNC(__kvm_tlb_flush_local_vmid): { unsigned long r1 =
host_ctxt->regs.regs[1]; struct kvm_s2_mmu *mmu = (struct kvm_s2_mmu *)r1;
__kvm_tlb_flush_local_vmid(kern_hyp_va(mmu)); break; }

Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>

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  reply	other threads:[~2020-11-02 13:29 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-26  9:51 [PATCH 0/8] KVM: arm64: Host EL2 entry improvements Marc Zyngier
2020-10-26  9:51 ` [PATCH 1/8] KVM: arm64: Don't corrupt tpidr_el2 on failed HVC call Marc Zyngier
2020-10-26 14:36   ` Quentin Perret
2020-10-26  9:51 ` [PATCH 2/8] KVM: arm64: Remove leftover kern_hyp_va() in nVHE TLB invalidation Marc Zyngier
2020-11-02 13:30   ` Alexandru Elisei [this message]
2020-10-26  9:51 ` [PATCH 3/8] KVM: arm64: Drop useless PAN setting on host EL1 to EL2 transition Marc Zyngier
2020-10-26 10:48   ` Vladimir Murzin
2020-10-26  9:51 ` [PATCH 4/8] KVM: arm64: Add kimg_hyp_va() helper Marc Zyngier
2020-10-26  9:51 ` [PATCH 5/8] KVM: arm64: Turn host HVC handling into a dispatch table Marc Zyngier
2020-11-02 14:19   ` Alexandru Elisei
2020-10-26  9:51 ` [PATCH 6/8] KVM: arm64: Patch kimage_voffset instead of loading the EL1 value Marc Zyngier
2020-10-26  9:51 ` [PATCH 7/8] KVM: arm64: Simplify __kvm_enable_ssbs() Marc Zyngier
2020-11-02 15:30   ` Alexandru Elisei
2020-10-26  9:51 ` [PATCH 8/8] KVM: arm64: Avoid repetitive stack access on host EL1 to EL2 exception Marc Zyngier
2020-11-02 16:28   ` Alexandru Elisei

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