Re: [PATCH 1/7] KVM: Pass mmu_notifier_range down to kvm_unmap_hva_range()

From: Suzuki Kuruppassery Poulose <suzuki.poulose@arm.com>
To: Marc Zyngier <maz@kernel.org>
Cc: "James Morse" <james.morse@arm.com>,
	"Julien Thierry" <julien.thierry.kdev@gmail.com>,
	"James Hogan" <jhogan@kernel.org>,
	"Paul Mackerras" <paulus@ozlabs.org>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Sean Christopherson" <sean.j.christopherson@intel.com>,
	"Vitaly Kuznetsov" <vkuznets@redhat.com>,
	"Wanpeng Li" <wanpengli@tencent.com>,
	"Jim Mattson" <jmattson@google.com>,
	"Joerg Roedel" <joro@8bytes.org>,
	linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org,
	kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH 1/7] KVM: Pass mmu_notifier_range down to kvm_unmap_hva_range()
Date: Fri, 13 Dec 2019 18:59:32 +0000	[thread overview]
Message-ID: <c347df67-6cc3-9d5c-0dd9-72ebb8fa9712@arm.com> (raw)
In-Reply-To: <20191213182503.14460-2-maz@kernel.org>

Hi Marc,

On 13/12/2019 18:24, Marc Zyngier wrote:
> kvm_unmap_hva_range() is currently passed both start and end
> fields from the mmu_notifier_range structure. As this struct
> now contains important information about the reason of the
> unmap (the event field), replace the start/end parameters
> with the range struct, and update all architectures.
> 
> No functionnal change.
> 
> Signed-off-by: Marc Zyngier <maz@kernel.org>

> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 00268290dcbd..7c3665ad1035 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -158,7 +158,7 @@ static unsigned long long kvm_createvm_count;
>   static unsigned long long kvm_active_vms;
>   
>   __weak int kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
> -		unsigned long start, unsigned long end, bool blockable)
> +		const struct mmu_notifier_range *range, bool blockable)
>   {
>   	return 0;
>   }
> @@ -415,7 +415,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
>   	 * count is also read inside the mmu_lock critical section.
>   	 */
>   	kvm->mmu_notifier_count++;
> -	need_tlb_flush = kvm_unmap_hva_range(kvm, range->start, range->end);
> +	need_tlb_flush = kvm_unmap_hva_range(kvm, range);
>   	need_tlb_flush |= kvm->tlbs_dirty;
>   	/* we've to flush the tlb before the pages can be freed */
>   	if (need_tlb_flush)
> @@ -423,8 +423,7 @@ static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
>   
>   	spin_unlock(&kvm->mmu_lock);
>   
> -	ret = kvm_arch_mmu_notifier_invalidate_range(kvm, range->start,
> -					range->end,
> +	ret = kvm_arch_mmu_notifier_invalidate_range(kvm, range,
>   					mmu_notifier_range_blockable(range));

minor nit:

Since we now have the range passed on to the arch hooks, we could get
rid of the "blockable" too, as it is something you can deduce from the
range.

Otherwise looks good to me.

Suzuki