linux-kernel - Re: [PATCH v12 58/84] KVM: RISC-V: Use kvm_faultin

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Message-ID: <20240731-a5f8928d385945f049e5f96e@orel>
Date: Wed, 31 Jul 2024 10:11:14 +0200
From: Andrew Jones <ajones@...tanamicro.com>
To: Sean Christopherson <seanjc@...gle.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>, Marc Zyngier <maz@...nel.org>, 
	Oliver Upton <oliver.upton@...ux.dev>, Tianrui Zhao <zhaotianrui@...ngson.cn>, 
	Bibo Mao <maobibo@...ngson.cn>, Huacai Chen <chenhuacai@...nel.org>, 
	Michael Ellerman <mpe@...erman.id.au>, Anup Patel <anup@...infault.org>, 
	Paul Walmsley <paul.walmsley@...ive.com>, Palmer Dabbelt <palmer@...belt.com>, 
	Albert Ou <aou@...s.berkeley.edu>, Christian Borntraeger <borntraeger@...ux.ibm.com>, 
	Janosch Frank <frankja@...ux.ibm.com>, Claudio Imbrenda <imbrenda@...ux.ibm.com>, kvm@...r.kernel.org, 
	linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev, loongarch@...ts.linux.dev, 
	linux-mips@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org, kvm-riscv@...ts.infradead.org, 
	linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org, 
	David Matlack <dmatlack@...gle.com>, David Stevens <stevensd@...omium.org>
Subject: Re: [PATCH v12 58/84] KVM: RISC-V: Use kvm_faultin_pfn() when
 mapping pfns into the guest

On Fri, Jul 26, 2024 at 04:52:07PM GMT, Sean Christopherson wrote:
> Convert RISC-V to __kvm_faultin_pfn()+kvm_release_faultin_page(), which
> are new APIs to consolidate arch code and provide consistent behavior
> across all KVM architectures.
> 
> Signed-off-by: Sean Christopherson <seanjc@...gle.com>
> ---
>  arch/riscv/kvm/mmu.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
> index 806f68e70642..f73d6a79a78c 100644
> --- a/arch/riscv/kvm/mmu.c
> +++ b/arch/riscv/kvm/mmu.c
> @@ -601,6 +601,7 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
>  	bool logging = (memslot->dirty_bitmap &&
>  			!(memslot->flags & KVM_MEM_READONLY)) ? true : false;
>  	unsigned long vma_pagesize, mmu_seq;
> +	struct page *page;
>  
>  	/* We need minimum second+third level pages */
>  	ret = kvm_mmu_topup_memory_cache(pcache, gstage_pgd_levels);
> @@ -631,7 +632,7 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
>  
>  	/*
>  	 * Read mmu_invalidate_seq so that KVM can detect if the results of
> -	 * vma_lookup() or gfn_to_pfn_prot() become stale priort to acquiring
> +	 * vma_lookup() or __kvm_faultin_pfn() become stale priort to acquiring
                                                            ^ while here
						could fix this typo

>  	 * kvm->mmu_lock.
>  	 *
>  	 * Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs
> @@ -647,7 +648,7 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
>  		return -EFAULT;
>  	}
>  
> -	hfn = gfn_to_pfn_prot(kvm, gfn, is_write, &writable);
> +	hfn = kvm_faultin_pfn(vcpu, gfn, is_write, &writable, &page);
>  	if (hfn == KVM_PFN_ERR_HWPOISON) {
>  		send_sig_mceerr(BUS_MCEERR_AR, (void __user *)hva,
>  				vma_pageshift, current);
> @@ -681,11 +682,7 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
>  		kvm_err("Failed to map in G-stage\n");
>  
>  out_unlock:
> -	if ((!ret || ret == -EEXIST) && writable)
> -		kvm_set_pfn_dirty(hfn);
> -	else
> -		kvm_release_pfn_clean(hfn);
> -
> +	kvm_release_faultin_page(kvm, page, ret && ret != -EEXIST, writable);
>  	spin_unlock(&kvm->mmu_lock);
>  	return ret;
>  }
> -- 
> 2.46.0.rc1.232.g9752f9e123-goog
> 
>

Reviewed-by: Andrew Jones <ajones@...tanamicro.com>