Re: [Xen-devel] [PATCH v2 05/16] xen/arm: mm: Redefine virt_to_mfn to support typesafe

[Stefano Stabellini]

On Mon, 19 Jun 2017, Julien Grall wrote:
> The file xen/arch/arm/mm.c is using the typesafe MFN in most of the
> place. This requires all caller of virt_to_mfn to prefixed by _mfn(...).
> 
> To avoid the extra _mfn(...), re-defined virt_to_mfn within arch/arm/mm.c
> to handle typesafe MFN.
> 
> This patch also introduce __virt_to_mfn, so virt_to_mfn can be
> re-defined easily.
> 
> Signed-off-by: Julien Grall 

Reviewed-by: Stefano Stabellini 



> Changes in v2:
> - Use __virt_to_mfn rather than mfn_x(virt_to_mfn()).
> ---
>  xen/arch/arm/mm.c| 16 ++--
>  xen/include/asm-arm/mm.h |  3 ++-
>  2 files changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
> index 452c1e26c3..5612834dfc 100644
> --- a/xen/arch/arm/mm.c
> +++ b/xen/arch/arm/mm.c
> @@ -44,6 +44,10 @@
>  
>  struct domain *dom_xen, *dom_io, *dom_cow;
>  
> +/* Override macros from asm/page.h to make them work with mfn_t */
> +#undef virt_to_mfn
> +#define virt_to_mfn(va) _mfn(__virt_to_mfn(va))
> +
>  /* Static start-of-day pagetables that we use before the allocators
>   * are up. These are used by all CPUs during bringup before switching
>   * to the CPUs own pagetables.
> @@ -479,7 +483,7 @@ unsigned long domain_page_map_to_mfn(const void *ptr)
>  unsigned long offset = (va>>THIRD_SHIFT) & LPAE_ENTRY_MASK;
>  
>  if ( va >= VMAP_VIRT_START && va < VMAP_VIRT_END )
> -return virt_to_mfn(va);
> +return __virt_to_mfn(va);
>  
>  ASSERT(slot >= 0 && slot < DOMHEAP_ENTRIES);
>  ASSERT(map[slot].pt.avail != 0);
> @@ -764,7 +768,7 @@ int init_secondary_pagetables(int cpu)
>   * domheap mapping pages. */
>  for ( i = 0; i < DOMHEAP_SECOND_PAGES; i++ )
>  {
> -pte = mfn_to_xen_entry(_mfn(virt_to_mfn(domheap+i*LPAE_ENTRIES)),
> +pte = mfn_to_xen_entry(virt_to_mfn(domheap+i*LPAE_ENTRIES),
> WRITEALLOC);
>  pte.pt.table = 1;
>  
> write_pte([first_table_offset(DOMHEAP_VIRT_START+i*FIRST_SIZE)], pte);
> @@ -961,7 +965,7 @@ static int create_xen_table(lpae_t *entry)
>  if ( p == NULL )
>  return -ENOMEM;
>  clear_page(p);
> -pte = mfn_to_xen_entry(_mfn(virt_to_mfn(p)), WRITEALLOC);
> +pte = mfn_to_xen_entry(virt_to_mfn(p), WRITEALLOC);
>  pte.pt.table = 1;
>  write_pte(entry, pte);
>  return 0;
> @@ -1216,7 +1220,7 @@ int xenmem_add_to_physmap_one(
>  unsigned long idx,
>  gfn_t gfn)
>  {
> -unsigned long mfn = 0;
> +mfn_t mfn = INVALID_MFN;
>  int rc;
>  p2m_type_t t;
>  struct page_info *page = NULL;
> @@ -1302,7 +1306,7 @@ int xenmem_add_to_physmap_one(
>  return -EINVAL;
>  }
>  
> -mfn = page_to_mfn(page);
> +mfn = _mfn(page_to_mfn(page));
>  t = p2m_map_foreign;
>  
>  rcu_unlock_domain(od);
> @@ -1321,7 +1325,7 @@ int xenmem_add_to_physmap_one(
>  }
>  
>  /* Map at new location. */
> -rc = guest_physmap_add_entry(d, gfn, _mfn(mfn), 0, t);
> +rc = guest_physmap_add_entry(d, gfn, mfn, 0, t);
>  
>  /* If we fail to add the mapping, we need to drop the reference we
>   * took earlier on foreign pages */
> diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
> index b2e7ea7761..6e2b3c7f2b 100644
> --- a/xen/include/asm-arm/mm.h
> +++ b/xen/include/asm-arm/mm.h
> @@ -264,7 +264,7 @@ static inline int gvirt_to_maddr(vaddr_t va, paddr_t *pa, 
> unsigned int flags)
>  #define __va(x) (maddr_to_virt(x))
>  
>  /* Convert between Xen-heap virtual addresses and machine frame numbers. */
> -#define virt_to_mfn(va)   (virt_to_maddr(va) >> PAGE_SHIFT)
> +#define __virt_to_mfn(va) (virt_to_maddr(va) >> PAGE_SHIFT)
>  #define mfn_to_virt(mfn)  (maddr_to_virt((paddr_t)(mfn) << PAGE_SHIFT))
>  
>  /*
> @@ -274,6 +274,7 @@ static inline int gvirt_to_maddr(vaddr_t va, paddr_t *pa, 
> unsigned int flags)
>   */
>  #define mfn_to_page(mfn)__mfn_to_page(mfn)
>  #define page_to_mfn(pg) __page_to_mfn(pg)
> +#define virt_to_mfn(va) __virt_to_mfn(va)
>  
>  /* Convert between Xen-heap virtual addresses and page-info structures. */
>  static inline struct page_info *virt_to_page(const void *v)
> -- 
> 2.11.0
> 

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[Xen-devel] [PATCH v2 05/16] xen/arm: mm: Redefine virt_to_mfn to support typesafe

[Julien Grall]

The file xen/arch/arm/mm.c is using the typesafe MFN in most of the
place. This requires all caller of virt_to_mfn to prefixed by _mfn(...).

To avoid the extra _mfn(...), re-defined virt_to_mfn within arch/arm/mm.c
to handle typesafe MFN.

This patch also introduce __virt_to_mfn, so virt_to_mfn can be
re-defined easily.

Signed-off-by: Julien Grall 
---
Changes in v2:
- Use __virt_to_mfn rather than mfn_x(virt_to_mfn()).
---
 xen/arch/arm/mm.c| 16 ++--
 xen/include/asm-arm/mm.h |  3 ++-
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 452c1e26c3..5612834dfc 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -44,6 +44,10 @@
 
 struct domain *dom_xen, *dom_io, *dom_cow;
 
+/* Override macros from asm/page.h to make them work with mfn_t */
+#undef virt_to_mfn
+#define virt_to_mfn(va) _mfn(__virt_to_mfn(va))
+
 /* Static start-of-day pagetables that we use before the allocators
  * are up. These are used by all CPUs during bringup before switching
  * to the CPUs own pagetables.
@@ -479,7 +483,7 @@ unsigned long domain_page_map_to_mfn(const void *ptr)
 unsigned long offset = (va>>THIRD_SHIFT) & LPAE_ENTRY_MASK;
 
 if ( va >= VMAP_VIRT_START && va < VMAP_VIRT_END )
-return virt_to_mfn(va);
+return __virt_to_mfn(va);
 
 ASSERT(slot >= 0 && slot < DOMHEAP_ENTRIES);
 ASSERT(map[slot].pt.avail != 0);
@@ -764,7 +768,7 @@ int init_secondary_pagetables(int cpu)
  * domheap mapping pages. */
 for ( i = 0; i < DOMHEAP_SECOND_PAGES; i++ )
 {
-pte = mfn_to_xen_entry(_mfn(virt_to_mfn(domheap+i*LPAE_ENTRIES)),
+pte = mfn_to_xen_entry(virt_to_mfn(domheap+i*LPAE_ENTRIES),
WRITEALLOC);
 pte.pt.table = 1;
 write_pte([first_table_offset(DOMHEAP_VIRT_START+i*FIRST_SIZE)], 
pte);
@@ -961,7 +965,7 @@ static int create_xen_table(lpae_t *entry)
 if ( p == NULL )
 return -ENOMEM;
 clear_page(p);
-pte = mfn_to_xen_entry(_mfn(virt_to_mfn(p)), WRITEALLOC);
+pte = mfn_to_xen_entry(virt_to_mfn(p), WRITEALLOC);
 pte.pt.table = 1;
 write_pte(entry, pte);
 return 0;
@@ -1216,7 +1220,7 @@ int xenmem_add_to_physmap_one(
 unsigned long idx,
 gfn_t gfn)
 {
-unsigned long mfn = 0;
+mfn_t mfn = INVALID_MFN;
 int rc;
 p2m_type_t t;
 struct page_info *page = NULL;
@@ -1302,7 +1306,7 @@ int xenmem_add_to_physmap_one(
 return -EINVAL;
 }
 
-mfn = page_to_mfn(page);
+mfn = _mfn(page_to_mfn(page));
 t = p2m_map_foreign;
 
 rcu_unlock_domain(od);
@@ -1321,7 +1325,7 @@ int xenmem_add_to_physmap_one(
 }
 
 /* Map at new location. */
-rc = guest_physmap_add_entry(d, gfn, _mfn(mfn), 0, t);
+rc = guest_physmap_add_entry(d, gfn, mfn, 0, t);
 
 /* If we fail to add the mapping, we need to drop the reference we
  * took earlier on foreign pages */
diff --git a/xen/include/asm-arm/mm.h b/xen/include/asm-arm/mm.h
index b2e7ea7761..6e2b3c7f2b 100644
--- a/xen/include/asm-arm/mm.h
+++ b/xen/include/asm-arm/mm.h
@@ -264,7 +264,7 @@ static inline int gvirt_to_maddr(vaddr_t va, paddr_t *pa, 
unsigned int flags)
 #define __va(x) (maddr_to_virt(x))
 
 /* Convert between Xen-heap virtual addresses and machine frame numbers. */
-#define virt_to_mfn(va)   (virt_to_maddr(va) >> PAGE_SHIFT)
+#define __virt_to_mfn(va) (virt_to_maddr(va) >> PAGE_SHIFT)
 #define mfn_to_virt(mfn)  (maddr_to_virt((paddr_t)(mfn) << PAGE_SHIFT))
 
 /*
@@ -274,6 +274,7 @@ static inline int gvirt_to_maddr(vaddr_t va, paddr_t *pa, 
unsigned int flags)
  */
 #define mfn_to_page(mfn)__mfn_to_page(mfn)
 #define page_to_mfn(pg) __page_to_mfn(pg)
+#define virt_to_mfn(va) __virt_to_mfn(va)
 
 /* Convert between Xen-heap virtual addresses and page-info structures. */
 static inline struct page_info *virt_to_page(const void *v)
-- 
2.11.0


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