diff mbox series

[v2,3/9] xen/arm: allocate static shared memory to a specific owner domain

Message ID 20220506072502.2177828-4-Penny.Zheng@arm.com (mailing list archive)
State Superseded
Headers show
Series static shared memory on dom0less system | expand

Commit Message

Penny Zheng May 6, 2022, 7:24 a.m. UTC
If owner property is defined, then owner domain of a static shared memory
region is not the default dom_io anymore, but a specific domain.

This commit implements allocating static shared memory to a specific domain
when owner property is defined.

Coding flow for dealing borrower domain will be introduced later in the
following commits.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
---
v2 change:
- P2M mapping is restricted to normal domain
- in-code comment fix
---
 xen/arch/arm/domain_build.c | 55 +++++++++++++++++++++++++++++--------
 1 file changed, 43 insertions(+), 12 deletions(-)

Comments

Stefano Stabellini May 7, 2022, 1:08 a.m. UTC | #1
On Fri, 6 May 2022, Penny Zheng wrote:
> If owner property is defined, then owner domain of a static shared memory
> region is not the default dom_io anymore, but a specific domain.
> 
> This commit implements allocating static shared memory to a specific domain
> when owner property is defined.
> 
> Coding flow for dealing borrower domain will be introduced later in the
> following commits.
> 
> Signed-off-by: Penny Zheng <penny.zheng@arm.com>
> ---
> v2 change:
> - P2M mapping is restricted to normal domain
> - in-code comment fix
> ---
>  xen/arch/arm/domain_build.c | 55 +++++++++++++++++++++++++++++--------
>  1 file changed, 43 insertions(+), 12 deletions(-)
> 
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index e97bb6eeba..f43378227a 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -798,9 +798,11 @@ static mfn_t __init acquire_shared_memory_bank(struct domain *d,
>   */
>  static int __init allocate_shared_memory(struct domain *d,
>                                           u32 addr_cells, u32 size_cells,
> -                                         paddr_t pbase, paddr_t psize)
> +                                         paddr_t pbase, paddr_t psize,
> +                                         paddr_t gbase)
>  {
>      mfn_t smfn;
> +    int ret = 0;
>  
>      dprintk(XENLOG_INFO,
>              "Allocate static shared memory BANK %#"PRIpaddr"-%#"PRIpaddr".\n",
> @@ -813,10 +815,20 @@ static int __init allocate_shared_memory(struct domain *d,
>  
>      /*
>       * DOMID_IO is the domain, like DOMID_XEN, that is not auto-translated.
> -     * It sees RAM 1:1 and we do not need to create P2M mapping for it
> +     * It sees RAM 1:1 and we do not need to create P2M mapping for it.
>       */
> -    ASSERT(d == dom_io);
> -    return 0;
> +    if ( d != dom_io )
> +    {
> +        ret = guest_physmap_add_pages(d, gaddr_to_gfn(gbase), smfn, PFN_DOWN(psize));
> +        if ( ret )
> +        {
> +            printk(XENLOG_ERR
> +                   "Failed to map shared memory to %pd.\n", d);
> +            return ret;
> +        }
> +    }
> +
> +    return ret;
>  }
>  
>  static int __init process_shm(struct domain *d,
> @@ -829,6 +841,8 @@ static int __init process_shm(struct domain *d,
>      u32 shm_id;
>      u32 addr_cells, size_cells;
>      paddr_t gbase, pbase, psize;
> +    const char *role_str;
> +    bool owner_dom_io = true;
>  
>      dt_for_each_child_node(node, shm_node)
>      {
> @@ -855,19 +869,36 @@ static int __init process_shm(struct domain *d,
>          ASSERT(IS_ALIGNED(pbase, PAGE_SIZE) && IS_ALIGNED(psize, PAGE_SIZE));
>          gbase = dt_read_number(cells, addr_cells);
>  
> -        /* TODO: Consider owner domain is not the default dom_io. */
> +        /*
> +         * "role" property is optional and if it is defined explicitly,
> +         * then the owner domain is not the default "dom_io" domain.
> +         */
> +        if ( dt_property_read_string(shm_node, "role", &role_str) == 0 )
> +            owner_dom_io = false;
> +
>          /*
>           * Per static shared memory region could be shared between multiple
>           * domains.
> -         * In case re-allocating the same shared memory region, we check
> -         * if it is already allocated to the default owner dom_io before
> -         * the actual allocation.
> +         * So when owner domain is the default dom_io, in case re-allocating
> +         * the same shared memory region, we check if it is already allocated
> +         * to the default owner dom_io before the actual allocation.
>           */
> -        if ( !is_shm_allocated_to_domio(pbase) )
> +        if ( (owner_dom_io && !is_shm_allocated_to_domio(pbase)) ||
> +             (!owner_dom_io && strcmp(role_str, "owner") == 0) )
>          {
> -            /* Allocate statically shared pages to the default owner dom_io. */
> -            ret = allocate_shared_memory(dom_io, addr_cells, size_cells,
> -                                         pbase, psize);
> +            struct domain *od = d;
> +            paddr_t o_gbase = gbase;
> +
> +            if ( owner_dom_io )
> +            {
> +                od = dom_io;
> +                /* For dom_io, GFN is always equal to PFN. */
> +                o_gbase = pbase;
> +            }
>

o_gbase is not used if the domain is dom_io, so I would simplify it
further to:

ret = allocate_shared_memory(owner_dom_io ? dom_io : d,
                             addr_cells, size_cells,
                             pbase, psize, gbase);





> +            /* Allocate statically shared pages to the owner domain. */
> +            ret = allocate_shared_memory(od, addr_cells, size_cells,
> +                                         pbase, psize, o_gbase);
>              if ( ret )
>                  return ret;
>          }
> -- 
> 2.25.1
>
diff mbox series

Patch

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index e97bb6eeba..f43378227a 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -798,9 +798,11 @@  static mfn_t __init acquire_shared_memory_bank(struct domain *d,
  */
 static int __init allocate_shared_memory(struct domain *d,
                                          u32 addr_cells, u32 size_cells,
-                                         paddr_t pbase, paddr_t psize)
+                                         paddr_t pbase, paddr_t psize,
+                                         paddr_t gbase)
 {
     mfn_t smfn;
+    int ret = 0;
 
     dprintk(XENLOG_INFO,
             "Allocate static shared memory BANK %#"PRIpaddr"-%#"PRIpaddr".\n",
@@ -813,10 +815,20 @@  static int __init allocate_shared_memory(struct domain *d,
 
     /*
      * DOMID_IO is the domain, like DOMID_XEN, that is not auto-translated.
-     * It sees RAM 1:1 and we do not need to create P2M mapping for it
+     * It sees RAM 1:1 and we do not need to create P2M mapping for it.
      */
-    ASSERT(d == dom_io);
-    return 0;
+    if ( d != dom_io )
+    {
+        ret = guest_physmap_add_pages(d, gaddr_to_gfn(gbase), smfn, PFN_DOWN(psize));
+        if ( ret )
+        {
+            printk(XENLOG_ERR
+                   "Failed to map shared memory to %pd.\n", d);
+            return ret;
+        }
+    }
+
+    return ret;
 }
 
 static int __init process_shm(struct domain *d,
@@ -829,6 +841,8 @@  static int __init process_shm(struct domain *d,
     u32 shm_id;
     u32 addr_cells, size_cells;
     paddr_t gbase, pbase, psize;
+    const char *role_str;
+    bool owner_dom_io = true;
 
     dt_for_each_child_node(node, shm_node)
     {
@@ -855,19 +869,36 @@  static int __init process_shm(struct domain *d,
         ASSERT(IS_ALIGNED(pbase, PAGE_SIZE) && IS_ALIGNED(psize, PAGE_SIZE));
         gbase = dt_read_number(cells, addr_cells);
 
-        /* TODO: Consider owner domain is not the default dom_io. */
+        /*
+         * "role" property is optional and if it is defined explicitly,
+         * then the owner domain is not the default "dom_io" domain.
+         */
+        if ( dt_property_read_string(shm_node, "role", &role_str) == 0 )
+            owner_dom_io = false;
+
         /*
          * Per static shared memory region could be shared between multiple
          * domains.
-         * In case re-allocating the same shared memory region, we check
-         * if it is already allocated to the default owner dom_io before
-         * the actual allocation.
+         * So when owner domain is the default dom_io, in case re-allocating
+         * the same shared memory region, we check if it is already allocated
+         * to the default owner dom_io before the actual allocation.
          */
-        if ( !is_shm_allocated_to_domio(pbase) )
+        if ( (owner_dom_io && !is_shm_allocated_to_domio(pbase)) ||
+             (!owner_dom_io && strcmp(role_str, "owner") == 0) )
         {
-            /* Allocate statically shared pages to the default owner dom_io. */
-            ret = allocate_shared_memory(dom_io, addr_cells, size_cells,
-                                         pbase, psize);
+            struct domain *od = d;
+            paddr_t o_gbase = gbase;
+
+            if ( owner_dom_io )
+            {
+                od = dom_io;
+                /* For dom_io, GFN is always equal to PFN. */
+                o_gbase = pbase;
+            }
+
+            /* Allocate statically shared pages to the owner domain. */
+            ret = allocate_shared_memory(od, addr_cells, size_cells,
+                                         pbase, psize, o_gbase);
             if ( ret )
                 return ret;
         }