diff mbox series

[v3,5/8] xen/arm: support static shared memory when host address not provided

Message ID 20230821040046.2965665-6-Penny.Zheng@arm.com (mailing list archive)
State Superseded
Headers show
Series Follow-up static shared memory PART I | expand

Commit Message

Penny Zheng Aug. 21, 2023, 4 a.m. UTC
In order to support static shared memory when host address not provided,
we shall do the following modification:
- we shall let Xen allocate memory from heap for static shared memory
at first domain, no matter it is owner or borrower.
- In acquire_shared_memory_bank, as static shared memory has already
been allocated from heap, we shall assign them to the owner domain
using function "assign_pages".
- Function get_shm_pages_reference is created to add as many
additional reference as the number of borrowers.
- We implement a new helper "add_foreign_mapping_for_borrower" to set
up foreign memory mapping for borrower.

Instead of using multiple function parameters to deliver various shm-related
info, like host physical address, SHMID, etc, and with the introduction
of new struct "shm_memnode" to include banked host memory info, we switch to
use "shm_memnode" as function parameter to replace them all, to make codes more
clear and tidy.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
---
v1 -> v2:
- combine commits 4 - 6 in Serie 1
- Adapt to changes of introducing "struct shm_memnode"
---
v2 -> v3
- fix infinite loop bug and bad indentation
- rebase
---
 xen/arch/arm/domain_build.c | 223 +++++++++++++++++++++++++-----------
 1 file changed, 155 insertions(+), 68 deletions(-)
diff mbox series

Patch

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index e37f3376a1..687420956f 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -891,6 +891,11 @@  static void __init assign_static_memory_11(struct domain *d,
 }
 
 #ifdef CONFIG_STATIC_SHM
+static bool __init is_shm_allocated_from_heap(struct shm_memnode *node)
+{
+    return (node->meminfo.nr_banks != 0);
+}
+
 static int __init acquire_nr_borrower_domain(const char *shm_id,
                                              unsigned long *nr_borrowers)
 {
@@ -934,12 +939,12 @@  static struct shm_memnode * __init find_shm_memnode(const char *shm_id)
  * This function checks whether the static shared memory region is
  * already allocated to dom_io.
  */
-static bool __init is_shm_allocated_to_domio(paddr_t pbase)
+static bool __init is_shm_allocated_to_domio(struct shm_memnode *node)
 {
     struct page_info *page;
     struct domain *d;
 
-    page = maddr_to_page(pbase);
+    page = maddr_to_page(node->meminfo.bank[0].start);
     d = page_get_owner_and_reference(page);
     if ( d == NULL )
         return false;
@@ -957,67 +962,128 @@  static bool __init is_shm_allocated_to_domio(paddr_t pbase)
 }
 
 static mfn_t __init acquire_shared_memory_bank(struct domain *d,
-                                               paddr_t pbase, paddr_t psize)
+                                               struct shm_meminfo *meminfo,
+                                               bool paddr_assigned)
 {
-    mfn_t smfn;
-    unsigned long nr_pfns;
-    int res;
+    int res, i = 0;
 
-    /*
-     * Pages of statically shared memory shall be included
-     * into domain_tot_pages().
-     */
-    nr_pfns = PFN_DOWN(psize);
-    if ( (UINT_MAX - d->max_pages) < nr_pfns )
+    for ( ; i < meminfo->nr_banks; i++ )
     {
-        printk(XENLOG_ERR "%pd: Over-allocation for d->max_pages: %lu.\n",
-               d, nr_pfns);
-        return INVALID_MFN;
+        paddr_t pbase = meminfo->bank[i].start, psize = meminfo->bank[i].size;
+        unsigned long nr_pfns;
+
+        /*
+         * Pages of statically shared memory shall be included
+         * into domain_tot_pages().
+         */
+        nr_pfns = PFN_DOWN(psize);
+        if ( (UINT_MAX - d->max_pages) < nr_pfns )
+        {
+            printk(XENLOG_ERR "%pd: Over-allocation for d->max_pages: %lu.\n",
+                   d, nr_pfns);
+            return INVALID_MFN;
+        }
+        d->max_pages += nr_pfns;
+
+        if ( paddr_assigned )
+        {
+            res = acquire_domstatic_pages(d, maddr_to_mfn(pbase), nr_pfns, 0);
+            if ( res )
+            {
+                printk(XENLOG_ERR
+                       "%pd: failed to acquire static memory: %d.\n", d, res);
+                goto fail;
+            }
+        }
+        else
+            /*
+             * When host address is not provided, static shared memory is
+             * allocated from heap and shall be assigned to owner domain.
+             */
+            if ( assign_pages(maddr_to_page(pbase), nr_pfns, d, 0) )
+                goto fail;
     }
-    d->max_pages += nr_pfns;
 
-    smfn = maddr_to_mfn(pbase);
-    res = acquire_domstatic_pages(d, smfn, nr_pfns, 0);
-    if ( res )
+    return maddr_to_mfn(meminfo->bank[0].start);
+
+ fail:
+    while( --i >= 0 )
+        d->max_pages -= PFN_DOWN(meminfo->bank[i].size);
+    return INVALID_MFN;
+}
+
+static int __init get_shm_pages_reference(struct domain *d,
+                                          struct shm_meminfo *meminfo,
+                                          unsigned long count)
+{
+    struct page_info *page;
+    int i = 0, j;
+
+    for ( ; i < meminfo->nr_banks; i++ )
     {
-        printk(XENLOG_ERR
-               "%pd: failed to acquire static memory: %d.\n", d, res);
-        d->max_pages -= nr_pfns;
-        return INVALID_MFN;
+        paddr_t pbase = meminfo->bank[i].start, psize = meminfo->bank[i].size;
+        unsigned long nr_pages = PFN_DOWN(psize);
+
+        page = maddr_to_page(pbase);
+        for ( j = 0; j < nr_pages; j++ )
+        {
+            if ( !get_page_nr(page + j, d, count) )
+            {
+                printk(XENLOG_ERR
+                       "Failed to add %lu references to page %"PRI_mfn".\n",
+                       count, mfn_x(page_to_mfn(page + j)));
+                goto fail;
+            }
+        }
     }
 
-    return smfn;
+    return 0;
+
+ fail:
+    while ( --j >= 0 )
+        put_page_nr(page + j, count);
+    while ( --i >= 0 )
+    {
+        page = maddr_to_page(meminfo->bank[i].start);
+        j = PFN_DOWN(meminfo->bank[i].size);
+        while ( --j >= 0 )
+            put_page_nr(page + j, count);
+    }
+    return -EINVAL;
 }
 
 static int __init assign_shared_memory(struct domain *d,
-                                       paddr_t pbase, paddr_t psize,
-                                       paddr_t gbase, const char *shm_id)
+                                       struct shm_memnode *node, paddr_t gbase,
+                                       bool paddr_assigned)
 {
     mfn_t smfn;
-    int ret = 0;
-    unsigned long nr_pages, nr_borrowers, i;
-    struct page_info *page;
-
-    printk("%pd: allocate static shared memory BANK %#"PRIpaddr"-%#"PRIpaddr".\n",
-           d, pbase, pbase + psize);
+    int ret;
+    unsigned long nr_borrowers, i;
+    struct shm_meminfo *meminfo = &node->meminfo;
 
-    smfn = acquire_shared_memory_bank(d, pbase, psize);
+    smfn = acquire_shared_memory_bank(d, meminfo, paddr_assigned);
     if ( mfn_eq(smfn, INVALID_MFN) )
         return -EINVAL;
 
-    /*
-     * DOMID_IO is not auto-translated (i.e. it sees RAM 1:1). So we do not need
-     * to create mapping in the P2M.
-     */
-    nr_pages = PFN_DOWN(psize);
-    if ( d != dom_io )
+    for ( i = 0; i < meminfo->nr_banks; i++ )
     {
-        ret = guest_physmap_add_pages(d, gaddr_to_gfn(gbase), smfn,
-                                      PFN_DOWN(psize));
-        if ( ret )
+        paddr_t pbase = meminfo->bank[i].start, psize = meminfo->bank[i].size;
+
+        /*
+         * DOMID_IO is not auto-translated (i.e. it sees RAM 1:1). So we do
+         * not need to create mapping in the P2M.
+         */
+        if ( d != dom_io )
         {
-            printk(XENLOG_ERR "Failed to map shared memory to %pd.\n", d);
-            return ret;
+            ret = guest_physmap_add_pages(d, gaddr_to_gfn(gbase),
+                                          maddr_to_mfn(pbase),
+                                          PFN_DOWN(psize));
+            if ( ret )
+            {
+                printk(XENLOG_ERR "Failed to map shared memory to %pd.\n", d);
+                return ret;
+            }
+            gbase += psize;
         }
     }
 
@@ -1025,7 +1091,7 @@  static int __init assign_shared_memory(struct domain *d,
      * Get the right amount of references per page, which is the number of
      * borrower domains.
      */
-    ret = acquire_nr_borrower_domain(shm_id, &nr_borrowers);
+    ret = acquire_nr_borrower_domain(node->shm_id, &nr_borrowers);
     if ( ret )
         return ret;
 
@@ -1037,24 +1103,30 @@  static int __init assign_shared_memory(struct domain *d,
      * So if the borrower is created first, it will cause adding pages
      * in the P2M without reference.
      */
-    page = mfn_to_page(smfn);
-    for ( i = 0; i < nr_pages; i++ )
+    return get_shm_pages_reference(d, meminfo, nr_borrowers);
+}
+
+static int __init add_foreign_mapping_for_borrower(struct domain *d,
+                                                   struct shm_memnode *node,
+                                                   paddr_t gbase)
+{
+    unsigned int i = 0;
+    struct shm_meminfo *meminfo = &node->meminfo;
+
+    for ( ; i < meminfo->nr_banks; i++ )
     {
-        if ( !get_page_nr(page + i, d, nr_borrowers) )
-        {
-            printk(XENLOG_ERR
-                   "Failed to add %lu references to page %"PRI_mfn".\n",
-                   nr_borrowers, mfn_x(smfn) + i);
-            goto fail;
-        }
+        paddr_t pbase = meminfo->bank[i].start, psize = meminfo->bank[i].size;
+        int ret;
+
+        /* Set up P2M foreign mapping for borrower domain. */
+        ret = map_regions_p2mt(d, _gfn(PFN_UP(gbase)), PFN_DOWN(psize),
+                               _mfn(PFN_UP(pbase)), p2m_map_foreign_rw);
+        if ( ret )
+            return ret;
+        gbase += psize;
     }
 
     return 0;
-
- fail:
-    while ( --i >= 0 )
-        put_page_nr(page + i, nr_borrowers);
-    return ret;
 }
 
 static int __init append_shm_bank_to_domain(struct kernel_info *kinfo,
@@ -1178,7 +1250,7 @@  static int __init process_shm(struct domain *d, struct kernel_info *kinfo,
 
     dt_for_each_child_node(node, shm_node)
     {
-        paddr_t gbase, pbase, psize;
+        paddr_t gbase;
         int ret = 0;
         const char *role_str;
         const char *shm_id;
@@ -1207,15 +1279,30 @@  static int __init process_shm(struct domain *d, struct kernel_info *kinfo,
                                          shm_id);
         if ( !shm_memnode )
             return -EINVAL;
-        pbase = shm_memnode->meminfo.bank[0].start;
-        psize = shm_memnode->meminfo.bank[0].size;
+
+        /*
+         * When host address is not provided in "xen,shared-mem",
+         * we let Xen allocate memory from heap at first domain.
+         */
+        if ( !paddr_assigned && !is_shm_allocated_from_heap(shm_memnode) )
+        {
+            if ( !allocate_domheap_memory(NULL, shm_memnode->meminfo.tot_size,
+                                          (void *)&shm_memnode->meminfo,
+                                          SHM_MEMINFO) )
+            {
+                printk(XENLOG_ERR
+                       "Failed to allocate (%"PRIpaddr"MB) pages as static shared memory from heap\n",
+                       shm_memnode->meminfo.tot_size >> 20);
+                return -EINVAL;
+            }
+        }
 
         /*
          * DOMID_IO is a fake domain and is not described in the Device-Tree.
          * Therefore when the owner of the shared region is DOMID_IO, we will
          * only find the borrowers.
          */
-        if ( (owner_dom_io && !is_shm_allocated_to_domio(pbase)) ||
+        if ( (owner_dom_io && !is_shm_allocated_to_domio(shm_memnode)) ||
              (!owner_dom_io && strcmp(role_str, "owner") == 0) )
         {
             /*
@@ -1223,16 +1310,14 @@  static int __init process_shm(struct domain *d, struct kernel_info *kinfo,
              * specified, so they should be assigned to dom_io.
              */
             ret = assign_shared_memory(owner_dom_io ? dom_io : d,
-                                       pbase, psize, gbase, shm_id);
+                                       shm_memnode, gbase, paddr_assigned);
             if ( ret )
                 return ret;
         }
 
         if ( owner_dom_io || (strcmp(role_str, "borrower") == 0) )
         {
-            /* Set up P2M foreign mapping for borrower domain. */
-            ret = map_regions_p2mt(d, _gfn(PFN_UP(gbase)), PFN_DOWN(psize),
-                                   _mfn(PFN_UP(pbase)), p2m_map_foreign_rw);
+            ret = add_foreign_mapping_for_borrower(d, shm_memnode, gbase);
             if ( ret )
                 return ret;
         }
@@ -1241,7 +1326,9 @@  static int __init process_shm(struct domain *d, struct kernel_info *kinfo,
          * Record static shared memory region info for later setting
          * up shm-node in guest device tree.
          */
-        ret = append_shm_bank_to_domain(kinfo, gbase, psize, shm_id);
+        ret = append_shm_bank_to_domain(kinfo, gbase,
+                                        shm_memnode->meminfo.tot_size,
+                                        shm_memnode->shm_id);
         if ( ret )
             return ret;
     }