Re: [PATCH kernel v7 09/10] KVM: PPC: iommu: Unify TCE checking

[Alexey Kardashevskiy]

On 08/03/17 14:00, Alexey Kardashevskiy wrote:
> This reworks helpers for checking TCE update parameters in way they
> can be used in KVM.
> 
> This should cause no behavioral change.
> 
> Signed-off-by: Alexey Kardashevskiy 

(for patchwork) Forgot this from v6:

Reviewed-by: David Gibson 



> ---
> Changes:
> v6:
> * s/tce/gpa/ as TCE without permission bits is a GPA and this is what is
> passed everywhere
> ---
>  arch/powerpc/include/asm/iommu.h| 20 +++-
>  arch/powerpc/include/asm/kvm_ppc.h  |  6 --
>  arch/powerpc/kernel/iommu.c | 37 
> +
>  arch/powerpc/kvm/book3s_64_vio_hv.c | 31 +++
>  4 files changed, 39 insertions(+), 55 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/iommu.h 
> b/arch/powerpc/include/asm/iommu.h
> index 82e77ebf85f4..1e6b03339a68 100644
> --- a/arch/powerpc/include/asm/iommu.h
> +++ b/arch/powerpc/include/asm/iommu.h
> @@ -296,11 +296,21 @@ static inline void iommu_restore(void)
>  #endif
>  
>  /* The API to support IOMMU operations for VFIO */
> -extern int iommu_tce_clear_param_check(struct iommu_table *tbl,
> - unsigned long ioba, unsigned long tce_value,
> - unsigned long npages);
> -extern int iommu_tce_put_param_check(struct iommu_table *tbl,
> - unsigned long ioba, unsigned long tce);
> +extern int iommu_tce_check_ioba(unsigned long page_shift,
> + unsigned long offset, unsigned long size,
> + unsigned long ioba, unsigned long npages);
> +extern int iommu_tce_check_gpa(unsigned long page_shift,
> + unsigned long gpa);
> +
> +#define iommu_tce_clear_param_check(tbl, ioba, tce_value, npages) \
> + (iommu_tce_check_ioba((tbl)->it_page_shift,   \
> + (tbl)->it_offset, (tbl)->it_size, \
> + (ioba), (npages)) || (tce_value))
> +#define iommu_tce_put_param_check(tbl, ioba, gpa) \
> + (iommu_tce_check_ioba((tbl)->it_page_shift,   \
> + (tbl)->it_offset, (tbl)->it_size, \
> + (ioba), 1) || \
> + iommu_tce_check_gpa((tbl)->it_page_shift, (gpa)))
>  
>  extern void iommu_flush_tce(struct iommu_table *tbl);
>  extern int iommu_take_ownership(struct iommu_table *tbl);
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h 
> b/arch/powerpc/include/asm/kvm_ppc.h
> index eba8988d8443..72c2a155641f 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -169,8 +169,10 @@ extern long kvm_vm_ioctl_create_spapr_tce(struct kvm 
> *kvm,
>   struct kvm_create_spapr_tce_64 *args);
>  extern struct kvmppc_spapr_tce_table *kvmppc_find_table(
>   struct kvm *kvm, unsigned long liobn);
> -extern long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
> - unsigned long ioba, unsigned long npages);
> +#define kvmppc_ioba_validate(stt, ioba, npages) \
> + (iommu_tce_check_ioba((stt)->page_shift, (stt)->offset, \
> + (stt)->size, (ioba), (npages)) ?\
> + H_PARAMETER : H_SUCCESS)
>  extern long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *tt,
>   unsigned long tce);
>  extern long kvmppc_gpa_to_ua(struct kvm *kvm, unsigned long gpa,
> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
> index d02b8d22fb50..4269f9f1623b 100644
> --- a/arch/powerpc/kernel/iommu.c
> +++ b/arch/powerpc/kernel/iommu.c
> @@ -960,47 +960,36 @@ void iommu_flush_tce(struct iommu_table *tbl)
>  }
>  EXPORT_SYMBOL_GPL(iommu_flush_tce);
>  
> -int iommu_tce_clear_param_check(struct iommu_table *tbl,
> - unsigned long ioba, unsigned long tce_value,
> - unsigned long npages)
> +int iommu_tce_check_ioba(unsigned long page_shift,
> + unsigned long offset, unsigned long size,
> + unsigned long ioba, unsigned long npages)
>  {
> - /* tbl->it_ops->clear() does not support any value but 0 */
> - if (tce_value)
> - return -EINVAL;
> + unsigned long mask = (1UL << page_shift) - 1;
>  
> - if (ioba & ~IOMMU_PAGE_MASK(tbl))
> + if (ioba & mask)
>   return -EINVAL;
>  
> - ioba >>= tbl->it_page_shift;
> - if (ioba < tbl->it_offset)
> + ioba >>= page_shift;
> + if (ioba < offset)
>   return -EINVAL;
>  
> - if ((ioba + npages) > (tbl->it_offset + tbl->it_size))
> + if ((ioba + 1) > (offset + size))
>   return -EINVAL;
>  
>   return 0;
>  }
> -EXPORT_SYMBOL_GPL(iommu_tce_clear_param_check);
> +EXPORT_SYMBOL_GPL(iommu_tce_check_ioba);
>  
> -int iommu_tce_put_param_check(struct iommu_table *tbl,
> - unsigned long ioba, unsigned long tce)
> +int 

[PATCH kernel v7 09/10] KVM: PPC: iommu: Unify TCE checking

[Alexey Kardashevskiy]

This reworks helpers for checking TCE update parameters in way they
can be used in KVM.

This should cause no behavioral change.

Signed-off-by: Alexey Kardashevskiy 
---
Changes:
v6:
* s/tce/gpa/ as TCE without permission bits is a GPA and this is what is
passed everywhere
---
 arch/powerpc/include/asm/iommu.h| 20 +++-
 arch/powerpc/include/asm/kvm_ppc.h  |  6 --
 arch/powerpc/kernel/iommu.c | 37 +
 arch/powerpc/kvm/book3s_64_vio_hv.c | 31 +++
 4 files changed, 39 insertions(+), 55 deletions(-)

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 82e77ebf85f4..1e6b03339a68 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -296,11 +296,21 @@ static inline void iommu_restore(void)
 #endif
 
 /* The API to support IOMMU operations for VFIO */
-extern int iommu_tce_clear_param_check(struct iommu_table *tbl,
-   unsigned long ioba, unsigned long tce_value,
-   unsigned long npages);
-extern int iommu_tce_put_param_check(struct iommu_table *tbl,
-   unsigned long ioba, unsigned long tce);
+extern int iommu_tce_check_ioba(unsigned long page_shift,
+   unsigned long offset, unsigned long size,
+   unsigned long ioba, unsigned long npages);
+extern int iommu_tce_check_gpa(unsigned long page_shift,
+   unsigned long gpa);
+
+#define iommu_tce_clear_param_check(tbl, ioba, tce_value, npages) \
+   (iommu_tce_check_ioba((tbl)->it_page_shift,   \
+   (tbl)->it_offset, (tbl)->it_size, \
+   (ioba), (npages)) || (tce_value))
+#define iommu_tce_put_param_check(tbl, ioba, gpa) \
+   (iommu_tce_check_ioba((tbl)->it_page_shift,   \
+   (tbl)->it_offset, (tbl)->it_size, \
+   (ioba), 1) || \
+   iommu_tce_check_gpa((tbl)->it_page_shift, (gpa)))
 
 extern void iommu_flush_tce(struct iommu_table *tbl);
 extern int iommu_take_ownership(struct iommu_table *tbl);
diff --git a/arch/powerpc/include/asm/kvm_ppc.h 
b/arch/powerpc/include/asm/kvm_ppc.h
index eba8988d8443..72c2a155641f 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -169,8 +169,10 @@ extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
struct kvm_create_spapr_tce_64 *args);
 extern struct kvmppc_spapr_tce_table *kvmppc_find_table(
struct kvm *kvm, unsigned long liobn);
-extern long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
-   unsigned long ioba, unsigned long npages);
+#define kvmppc_ioba_validate(stt, ioba, npages) \
+   (iommu_tce_check_ioba((stt)->page_shift, (stt)->offset, \
+   (stt)->size, (ioba), (npages)) ?\
+   H_PARAMETER : H_SUCCESS)
 extern long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *tt,
unsigned long tce);
 extern long kvmppc_gpa_to_ua(struct kvm *kvm, unsigned long gpa,
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index d02b8d22fb50..4269f9f1623b 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -960,47 +960,36 @@ void iommu_flush_tce(struct iommu_table *tbl)
 }
 EXPORT_SYMBOL_GPL(iommu_flush_tce);
 
-int iommu_tce_clear_param_check(struct iommu_table *tbl,
-   unsigned long ioba, unsigned long tce_value,
-   unsigned long npages)
+int iommu_tce_check_ioba(unsigned long page_shift,
+   unsigned long offset, unsigned long size,
+   unsigned long ioba, unsigned long npages)
 {
-   /* tbl->it_ops->clear() does not support any value but 0 */
-   if (tce_value)
-   return -EINVAL;
+   unsigned long mask = (1UL << page_shift) - 1;
 
-   if (ioba & ~IOMMU_PAGE_MASK(tbl))
+   if (ioba & mask)
return -EINVAL;
 
-   ioba >>= tbl->it_page_shift;
-   if (ioba < tbl->it_offset)
+   ioba >>= page_shift;
+   if (ioba < offset)
return -EINVAL;
 
-   if ((ioba + npages) > (tbl->it_offset + tbl->it_size))
+   if ((ioba + 1) > (offset + size))
return -EINVAL;
 
return 0;
 }
-EXPORT_SYMBOL_GPL(iommu_tce_clear_param_check);
+EXPORT_SYMBOL_GPL(iommu_tce_check_ioba);
 
-int iommu_tce_put_param_check(struct iommu_table *tbl,
-   unsigned long ioba, unsigned long tce)
+int iommu_tce_check_gpa(unsigned long page_shift, unsigned long gpa)
 {
-   if (tce & ~IOMMU_PAGE_MASK(tbl))
-   return -EINVAL;
-
-   if (ioba & ~IOMMU_PAGE_MASK(tbl))
-   return -EINVAL;
-
-   ioba >>= tbl->it_page_shift;
-   if (ioba < tbl->it_offset)
-