[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[xen staging] xen/arm: Parse xen,shared-mem when host phys address is not provided



commit 1544d355b54ff17ebddc9c79e531329510488307
Author:     Luca Fancellu <luca.fancellu@xxxxxxx>
AuthorDate: Fri May 24 13:40:52 2024 +0100
Commit:     Julien Grall <jgrall@xxxxxxxxxx>
CommitDate: Fri Jun 14 10:46:01 2024 +0100

    xen/arm: Parse xen,shared-mem when host phys address is not provided
    
    Handle the parsing of the 'xen,shared-mem' property when the host physical
    address is not provided, this commit is introducing the logic to parse it,
    but the functionality is still not implemented and will be part of future
    commits.
    
    Rework the logic inside process_shm_node to check the shm_id before doing
    the other checks, because it ease the logic itself, add more comment on
    the logic.
    Now when the host physical address is not provided, the value
    INVALID_PADDR is chosen to signal this condition and it is stored as
    start of the bank, due to that change also early_print_info_shmem and
    init_sharedmem_pages are changed, to not handle banks with start equal
    to INVALID_PADDR.
    
    Another change is done inside meminfo_overlap_check, to skip banks that
    are starting with the start address INVALID_PADDR, that function is used
    to check banks from reserved memory, shared memory and ACPI and since
    the comment above the function states that wrapping around is not handled,
    it's unlikely for these bank to have the start address as INVALID_PADDR.
    Same change is done inside consider_modules, find_unallocated_memory and
    dt_unreserved_regions functions, in order to skip banks that starts with
    INVALID_PADDR from any computation.
    The changes above holds because of this consideration.
    
    Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>
    Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
---
 xen/arch/arm/arm32/mmu/mm.c |  11 +++-
 xen/arch/arm/domain_build.c |   5 ++
 xen/arch/arm/setup.c        |  14 +++--
 xen/arch/arm/static-shmem.c | 125 ++++++++++++++++++++++++++++++--------------
 4 files changed, 111 insertions(+), 44 deletions(-)

diff --git a/xen/arch/arm/arm32/mmu/mm.c b/xen/arch/arm/arm32/mmu/mm.c
index be480c31ea..30a7aa1e8e 100644
--- a/xen/arch/arm/arm32/mmu/mm.c
+++ b/xen/arch/arm/arm32/mmu/mm.c
@@ -101,8 +101,15 @@ static paddr_t __init consider_modules(paddr_t s, paddr_t 
e,
     nr += reserved_mem->nr_banks;
     for ( ; i - nr < shmem->nr_banks; i++ )
     {
-        paddr_t r_s = shmem->bank[i - nr].start;
-        paddr_t r_e = r_s + shmem->bank[i - nr].size;
+        paddr_t r_s, r_e;
+
+        r_s = shmem->bank[i - nr].start;
+
+        /* Shared memory banks can contain INVALID_PADDR as start */
+        if ( INVALID_PADDR == r_s )
+            continue;
+
+        r_e = r_s + shmem->bank[i - nr].size;
 
         if ( s < r_e && r_s < e )
         {
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 968c497efc..02e7416851 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -927,6 +927,11 @@ static int __init find_unallocated_memory(const struct 
kernel_info *kinfo,
         for ( j = 0; j < mem_banks[i]->nr_banks; j++ )
         {
             start = mem_banks[i]->bank[j].start;
+
+            /* Shared memory banks can contain INVALID_PADDR as start */
+            if ( INVALID_PADDR == start )
+                continue;
+
             end = mem_banks[i]->bank[j].start + mem_banks[i]->bank[j].size;
             res = rangeset_remove_range(unalloc_mem, PFN_DOWN(start),
                                         PFN_DOWN(end - 1));
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index c4e5c19b11..0c2fdaceaf 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -240,8 +240,15 @@ static void __init dt_unreserved_regions(paddr_t s, 
paddr_t e,
     offset = reserved_mem->nr_banks;
     for ( ; i - offset < shmem->nr_banks; i++ )
     {
-        paddr_t r_s = shmem->bank[i - offset].start;
-        paddr_t r_e = r_s + shmem->bank[i - offset].size;
+        paddr_t r_s, r_e;
+
+        r_s = shmem->bank[i - offset].start;
+
+        /* Shared memory banks can contain INVALID_PADDR as start */
+        if ( INVALID_PADDR == r_s )
+            continue;
+
+        r_e = r_s + shmem->bank[i - offset].size;
 
         if ( s < r_e && r_s < e )
         {
@@ -272,7 +279,8 @@ static bool __init meminfo_overlap_check(const struct 
membanks *mem,
         bank_start = mem->bank[i].start;
         bank_end = bank_start + mem->bank[i].size;
 
-        if ( region_end <= bank_start || region_start >= bank_end )
+        if ( INVALID_PADDR == bank_start || region_end <= bank_start ||
+             region_start >= bank_end )
             continue;
         else
         {
diff --git a/xen/arch/arm/static-shmem.c b/xen/arch/arm/static-shmem.c
index c15a651306..bc093b9da9 100644
--- a/xen/arch/arm/static-shmem.c
+++ b/xen/arch/arm/static-shmem.c
@@ -264,6 +264,12 @@ int __init process_shm(struct domain *d, struct 
kernel_info *kinfo,
         pbase = boot_shm_bank->start;
         psize = boot_shm_bank->size;
 
+        if ( INVALID_PADDR == pbase )
+        {
+            printk("%pd: host physical address must be chosen by users at the 
moment", d);
+            return -EINVAL;
+        }
+
         /*
          * xen,shared-mem = <pbase, gbase, size>;
          * TODO: pbase is optional.
@@ -377,7 +383,8 @@ int __init process_shm_node(const void *fdt, int node, 
uint32_t address_cells,
 {
     const struct fdt_property *prop, *prop_id, *prop_role;
     const __be32 *cell;
-    paddr_t paddr, gaddr, size, end;
+    paddr_t paddr = INVALID_PADDR;
+    paddr_t gaddr, size, end;
     struct membanks *mem = bootinfo_get_shmem();
     struct shmem_membank_extra *shmem_extra = bootinfo_get_shmem_extra();
     unsigned int i;
@@ -432,24 +439,37 @@ int __init process_shm_node(const void *fdt, int node, 
uint32_t address_cells,
     if ( !prop )
         return -ENOENT;
 
+    cell = (const __be32 *)prop->data;
     if ( len != dt_cells_to_size(address_cells + size_cells + address_cells) )
     {
-        if ( len == dt_cells_to_size(size_cells + address_cells) )
-            printk("fdt: host physical address must be chosen by users at the 
moment.\n");
-
-        printk("fdt: invalid `xen,shared-mem` property.\n");
-        return -EINVAL;
+        if ( len == dt_cells_to_size(address_cells + size_cells) )
+            device_tree_get_reg(&cell, address_cells, size_cells, &gaddr,
+                                &size);
+        else
+        {
+            printk("fdt: invalid `xen,shared-mem` property.\n");
+            return -EINVAL;
+        }
     }
+    else
+    {
+        device_tree_get_reg(&cell, address_cells, address_cells, &paddr,
+                            &gaddr);
+        size = dt_next_cell(size_cells, &cell);
 
-    cell = (const __be32 *)prop->data;
-    device_tree_get_reg(&cell, address_cells, address_cells, &paddr, &gaddr);
-    size = dt_next_cell(size_cells, &cell);
+        if ( !IS_ALIGNED(paddr, PAGE_SIZE) )
+        {
+            printk("fdt: physical address 0x%"PRIpaddr" is not suitably 
aligned.\n",
+                paddr);
+            return -EINVAL;
+        }
 
-    if ( !IS_ALIGNED(paddr, PAGE_SIZE) )
-    {
-        printk("fdt: physical address 0x%"PRIpaddr" is not suitably 
aligned.\n",
-               paddr);
-        return -EINVAL;
+        end = paddr + size;
+        if ( end <= paddr )
+        {
+            printk("fdt: static shared memory region %s overflow\n", shm_id);
+            return -EINVAL;
+        }
     }
 
     if ( !IS_ALIGNED(gaddr, PAGE_SIZE) )
@@ -471,39 +491,64 @@ int __init process_shm_node(const void *fdt, int node, 
uint32_t address_cells,
         return -EINVAL;
     }
 
-    end = paddr + size;
-    if ( end <= paddr )
-    {
-        printk("fdt: static shared memory region %s overflow\n", shm_id);
-        return -EINVAL;
-    }
-
     for ( i = 0; i < mem->nr_banks; i++ )
     {
         /*
          * Meet the following check:
-         * 1) The shm ID matches and the region exactly match
-         * 2) The shm ID doesn't match and the region doesn't overlap
-         * with an existing one
+         * - when host address is provided:
+         *   1) The shm ID matches and the region exactly match
+         *   2) The shm ID doesn't match and the region doesn't overlap
+         *      with an existing one
+         * - when host address is not provided:
+         *   1) The shm ID matches and the region size exactly match
          */
-        if ( paddr == mem->bank[i].start && size == mem->bank[i].size )
+        bool paddr_assigned = (INVALID_PADDR != paddr);
+
+        if ( strncmp(shm_id, shmem_extra[i].shm_id, MAX_SHM_ID_LENGTH) == 0 )
         {
-            if ( strncmp(shm_id, shmem_extra[i].shm_id,
-                         MAX_SHM_ID_LENGTH) == 0  )
+            /*
+             * Regions have same shm_id (cases):
+             * 1) physical host address is supplied:
+             *    - OK:   paddr is equal and size is equal (same region)
+             *    - Fail: paddr doesn't match or size doesn't match (there
+             *            cannot exists two shmem regions with same shm_id)
+             * 2) physical host address is NOT supplied:
+             *    - OK:   size is equal (same region)
+             *    - Fail: size is not equal (same shm_id must identify only one
+             *            region, there can't be two different regions with 
same
+             *            shm_id)
+             */
+            bool start_match = paddr_assigned ? (paddr == mem->bank[i].start) :
+                                                true;
+
+            if ( start_match && (size == mem->bank[i].size) )
                 break;
             else
             {
-                printk("fdt: xen,shm-id %s does not match for all the nodes 
using the same region.\n",
+                printk("fdt: different shared memory region could not share 
the same shm ID %s\n",
                        shm_id);
                 return -EINVAL;
             }
         }
-        else if ( strncmp(shm_id, shmem_extra[i].shm_id,
-                          MAX_SHM_ID_LENGTH) != 0 )
+
+        /*
+         * Regions have different shm_id (cases):
+         * 1) physical host address is supplied:
+         *    - OK:   paddr different, or size different (case where paddr
+         *            is equal but psize is different are wrong, but they
+         *            are handled later when checking for overlapping)
+         *    - Fail: paddr equal and size equal (the same region can't be
+         *            identified with different shm_id)
+         * 2) physical host address is NOT supplied:
+         *    - OK:   Both have different shm_id so even with same size they
+         *            can exists
+         */
+        if ( !paddr_assigned || (paddr != mem->bank[i].start) ||
+             (size != mem->bank[i].size) )
             continue;
         else
         {
-            printk("fdt: different shared memory region could not share the 
same shm ID %s\n",
+            printk("fdt: xen,shm-id %s does not match for all the nodes using 
the same region\n",
                    shm_id);
             return -EINVAL;
         }
@@ -513,7 +558,8 @@ int __init process_shm_node(const void *fdt, int node, 
uint32_t address_cells,
     {
         if (i < mem->max_banks)
         {
-            if ( check_reserved_regions_overlap(paddr, size) )
+            if ( (paddr != INVALID_PADDR) &&
+                 check_reserved_regions_overlap(paddr, size) )
                 return -EINVAL;
 
             /* Static shared memory shall be reserved from any other use. */
@@ -583,13 +629,13 @@ void __init early_print_info_shmem(void)
 {
     const struct membanks *shmem = bootinfo_get_shmem();
     unsigned int bank;
+    unsigned int printed = 0;
 
-    for ( bank = 0; bank < shmem->nr_banks; bank++ )
-    {
-        printk(" SHMEM[%u]: %"PRIpaddr" - %"PRIpaddr"\n", bank,
-               shmem->bank[bank].start,
-               shmem->bank[bank].start + shmem->bank[bank].size - 1);
-    }
+    for ( bank = 0; bank < shmem->nr_banks; bank++, printed++ )
+        if ( shmem->bank[bank].start != INVALID_PADDR )
+            printk(" SHMEM[%u]: %"PRIpaddr" - %"PRIpaddr"\n", printed,
+                shmem->bank[bank].start,
+                shmem->bank[bank].start + shmem->bank[bank].size - 1);
 }
 
 void __init init_sharedmem_pages(void)
@@ -598,7 +644,8 @@ void __init init_sharedmem_pages(void)
     unsigned int bank;
 
     for ( bank = 0 ; bank < shmem->nr_banks; bank++ )
-        init_staticmem_bank(&shmem->bank[bank]);
+        if ( shmem->bank[bank].start != INVALID_PADDR )
+            init_staticmem_bank(&shmem->bank[bank]);
 }
 
 int __init remove_shm_from_rangeset(const struct kernel_info *kinfo,
--
generated by git-patchbot for /home/xen/git/xen.git#staging



 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.