Re: [RFC PATCH 18/32] KVM: PPC: Book3S HV: Use kvmppc_unmap_pte() in kvm_unmap_radix()

[David Gibson <david@gibson.dropbear.id.au>]

[-- Attachment #1: Type: text/plain, Size: 4035 bytes --]

On Fri, Sep 21, 2018 at 08:01:49PM +1000, Paul Mackerras wrote:
> kvmppc_unmap_pte() does a sequence of operations that are open-coded in
> kvm_unmap_radix().  This extends kvmppc_unmap_pte() a little so that it
> can be used by kvm_unmap_radix(), and makes kvm_unmap_radix() call it.
> 
> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  arch/powerpc/kvm/book3s_64_mmu_radix.c | 36 ++++++++++++++--------------------
>  1 file changed, 15 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
> index 47f2b18..d9357e0 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
> @@ -240,21 +240,25 @@ static void kvmppc_pmd_free(pmd_t *pmdp)
>  }
>  
>  static void kvmppc_unmap_pte(struct kvm *kvm, pte_t *pte,
> -			     unsigned long gpa, unsigned int shift)
> +			     unsigned long gpa, unsigned int shift,
> +			     struct kvm_memory_slot *memslot)
>  
>  {
> -	unsigned long page_size = 1ul << shift;
>  	unsigned long old;
>  
>  	old = kvmppc_radix_update_pte(kvm, pte, ~0UL, 0, gpa, shift);
>  	kvmppc_radix_tlbie_page(kvm, gpa, shift);
>  	if (old & _PAGE_DIRTY) {
>  		unsigned long gfn = gpa >> PAGE_SHIFT;
> -		struct kvm_memory_slot *memslot;
> +		unsigned long page_size = PAGE_SIZE;
>  
> -		memslot = gfn_to_memslot(kvm, gfn);
> -		if (memslot && memslot->dirty_bitmap)
> +		if (shift)
> +			page_size = 1ul << shift;
> +		if (!memslot)
> +			memslot = gfn_to_memslot(kvm, gfn);
> +		if (memslot && memslot->dirty_bitmap) {
>  			kvmppc_update_dirty_map(memslot, gfn, page_size);
> +		}
>  	}
>  }
>  
> @@ -282,7 +286,7 @@ static void kvmppc_unmap_free_pte(struct kvm *kvm, pte_t *pte, bool full)
>  			WARN_ON_ONCE(1);
>  			kvmppc_unmap_pte(kvm, p,
>  					 pte_pfn(*p) << PAGE_SHIFT,
> -					 PAGE_SHIFT);
> +					 PAGE_SHIFT, NULL);
>  		}
>  	}
>  
> @@ -304,7 +308,7 @@ static void kvmppc_unmap_free_pmd(struct kvm *kvm, pmd_t *pmd, bool full)
>  				WARN_ON_ONCE(1);
>  				kvmppc_unmap_pte(kvm, (pte_t *)p,
>  					 pte_pfn(*(pte_t *)p) << PAGE_SHIFT,
> -					 PMD_SHIFT);
> +					 PMD_SHIFT, NULL);
>  			}
>  		} else {
>  			pte_t *pte;
> @@ -468,7 +472,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
>  			goto out_unlock;
>  		}
>  		/* Valid 1GB page here already, remove it */
> -		kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT);
> +		kvmppc_unmap_pte(kvm, (pte_t *)pud, hgpa, PUD_SHIFT, NULL);
>  	}
>  	if (level == 2) {
>  		if (!pud_none(*pud)) {
> @@ -517,7 +521,7 @@ static int kvmppc_create_pte(struct kvm *kvm, pgd_t *pgtable, pte_t pte,
>  			goto out_unlock;
>  		}
>  		/* Valid 2MB page here already, remove it */
> -		kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT);
> +		kvmppc_unmap_pte(kvm, pmdp_ptep(pmd), lgpa, PMD_SHIFT, NULL);
>  	}
>  	if (level == 1) {
>  		if (!pmd_none(*pmd)) {
> @@ -780,20 +784,10 @@ int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
>  	pte_t *ptep;
>  	unsigned long gpa = gfn << PAGE_SHIFT;
>  	unsigned int shift;
> -	unsigned long old;
>  
>  	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
> -	if (ptep && pte_present(*ptep)) {
> -		old = kvmppc_radix_update_pte(kvm, ptep, ~0UL, 0,
> -					      gpa, shift);
> -		kvmppc_radix_tlbie_page(kvm, gpa, shift);
> -		if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap) {
> -			unsigned long psize = PAGE_SIZE;
> -			if (shift)
> -				psize = 1ul << shift;
> -			kvmppc_update_dirty_map(memslot, gfn, psize);
> -		}
> -	}
> +	if (ptep && pte_present(*ptep))
> +		kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot);
>  	return 0;				
>  }
>  

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]