xen: arm: store per-boot module type instead of relying on index

This is more natural and better matches how multiboot is actually supposed to
work.

As part of this we need to modify consider_modules to handle Xen not
necessarily being module zero any more. To do this we first register a module
for Xen at the original load address and then update after we have relocated.
This is also fixing a latent issue which is that get_xen_paddr() would not
consider Xen's current physical address when picking the target address which
was buggy because the relocation code cannot handle the possibility of the old
and new locations overlapping.

All callers of consider_modules now consider the full range instead of some
skipping slot 0.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Julien Grall <julien.grall@linaro.org>

diff --git a/xen/arch/arm/bootfdt.c b/xen/arch/arm/bootfdt.c
index 23aff5a662437f06cc4afc5adfcaf20f0fc79ded..ce7fdf2843108416633aa13ee4801d6b432005a4 100644 (file)
--- a/xen/arch/arm/bootfdt.c
+++ b/xen/arch/arm/bootfdt.c
@@ -167,23 +167,22 @@ static void __init process_multiboot_node(const void *fdt, int node,
 {
     const struct fdt_property *prop;
     const __be32 *cell;
-    int nr;
-    struct bootmodule *mod;
+    bootmodule_kind kind;
+    paddr_t start, size;
+    const char *cmdline;
     int len;
 
     if ( fdt_node_check_compatible(fdt, node, "xen,linux-zimage") == 0 ||
          fdt_node_check_compatible(fdt, node, "multiboot,kernel") == 0 )
-        nr = MOD_KERNEL;
+        kind = BOOTMOD_KERNEL;
     else if ( fdt_node_check_compatible(fdt, node, "xen,linux-initrd") == 0 ||
               fdt_node_check_compatible(fdt, node, "multiboot,ramdisk") == 0 )
-        nr = MOD_INITRD;
+        kind = BOOTMOD_RAMDISK;
     else if ( fdt_node_check_compatible(fdt, node, "xen,xsm-policy") == 0 )
-        nr = MOD_XSM;
+        kind = BOOTMOD_XSM;
     else
         panic("%s not a known xen multiboot type\n", name);
 
-    mod = &bootinfo.modules.module[nr];
-
     prop = fdt_get_property(fdt, node, "reg", &len);
     if ( !prop )
         panic("node %s missing `reg' property\n", name);
@@ -193,22 +192,19 @@ static void __init process_multiboot_node(const void *fdt, int node,
                     name);
 
     cell = (const __be32 *)prop->data;
-    device_tree_get_reg(&cell, address_cells, size_cells,
-                        &mod->start, &mod->size);
+    device_tree_get_reg(&cell, address_cells, size_cells, &start, &size);
 
     prop = fdt_get_property(fdt, node, "bootargs", &len);
     if ( prop )
     {
-        if ( len > sizeof(mod->cmdline) )
-            panic("module %d command line too long\n", nr);
-
-        safe_strcpy(mod->cmdline, prop->data);
+        if ( len > BOOTMOD_MAX_CMDLINE )
+            panic("module %s command line too long\n", name);
+        cmdline = prop->data;
     }
     else
-        mod->cmdline[0] = 0;
+        cmdline = NULL;
 
-    if ( nr > bootinfo.modules.nr_mods )
-        bootinfo.modules.nr_mods = nr;
+    add_boot_module(kind, start, size, cmdline);
 }
 
 static void __init process_chosen_node(const void *fdt, int node,
@@ -216,7 +212,6 @@ static void __init process_chosen_node(const void *fdt, int node,
                                        u32 address_cells, u32 size_cells)
 {
     const struct fdt_property *prop;
-    struct bootmodule *mod = &bootinfo.modules.module[MOD_INITRD];
     paddr_t start, end;
     int len;
 
@@ -255,10 +250,7 @@ static void __init process_chosen_node(const void *fdt, int node,
 
     printk("Initrd %"PRIpaddr"-%"PRIpaddr"\n", start, end);
 
-    mod->start = start;
-    mod->size = end - start;
-
-    bootinfo.modules.nr_mods = max(MOD_INITRD, bootinfo.modules.nr_mods);
+    add_boot_module(BOOTMOD_RAMDISK, start, end-start, NULL);
 }
 
 static int __init early_scan_node(const void *fdt,
@@ -288,7 +280,7 @@ static void __init early_print_info(void)
                      mi->bank[i].start,
                      mi->bank[i].start + mi->bank[i].size - 1);
     printk("\n");
-    for ( i = 1 ; i < mods->nr_mods + 1; i++ )
+    for ( i = 0 ; i < mods->nr_mods; i++ )
         printk("MODULE[%d]: %"PRIpaddr" - %"PRIpaddr" %s\n",
                      i,
                      mods->module[i].start,
@@ -316,18 +308,13 @@ static void __init early_print_info(void)
  */
 size_t __init boot_fdt_info(const void *fdt, paddr_t paddr)
 {
-    struct bootmodule *mod;
     int ret;
 
     ret = fdt_check_header(fdt);
     if ( ret < 0 )
         panic("No valid device tree\n");
 
-    mod = &bootinfo.modules.module[MOD_FDT];
-    mod->start = paddr;
-    mod->size = fdt_totalsize(fdt);
-
-    bootinfo.modules.nr_mods = max(MOD_FDT, bootinfo.modules.nr_mods);
+    add_boot_module(BOOTMOD_FDT, paddr, fdt_totalsize(fdt), NULL);
 
     device_tree_for_each_node((void *)fdt, early_scan_node, NULL);
     early_print_info();
@@ -347,10 +334,8 @@ const char *boot_fdt_cmdline(const void *fdt)
     prop = fdt_get_property(fdt, node, "xen,xen-bootargs", NULL);
     if ( prop == NULL )
     {
-        struct bootmodule *dom0_mod = NULL;
-
-        if ( bootinfo.modules.nr_mods >= MOD_KERNEL )
-            dom0_mod = &bootinfo.modules.module[MOD_KERNEL];
+        struct bootmodule *dom0_mod =
+            boot_module_find_by_kind(BOOTMOD_KERNEL);
 
         if (fdt_get_property(fdt, node, "xen,dom0-bootargs", NULL) ||
             ( dom0_mod && dom0_mod->cmdline[0] ) )

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index a06544260dd8d3ba1f2dac10b51a6b75c0c8800e..154367e4cbe523543e5eb842c3270f17b4f3119f 100644 (file)
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -405,9 +405,10 @@ static int write_properties(struct domain *d, struct kernel_info *kinfo,
     int res = 0;
     int had_dom0_bootargs = 0;
 
-    if ( bootinfo.modules.nr_mods >= MOD_KERNEL &&
-         bootinfo.modules.module[MOD_KERNEL].cmdline[0] )
-        bootargs = &bootinfo.modules.module[MOD_KERNEL].cmdline[0];
+    struct bootmodule *mod = boot_module_find_by_kind(BOOTMOD_KERNEL);
+
+    if ( mod && mod->cmdline[0] )
+        bootargs = &mod->cmdline[0];
 
     dt_for_each_property_node (node, prop)
     {
@@ -454,6 +455,8 @@ static int write_properties(struct domain *d, struct kernel_info *kinfo,
 
     if ( dt_node_path_is_equal(node, "/chosen") )
     {
+        struct bootmodule *mod = boot_module_find_by_kind(BOOTMOD_RAMDISK);
+
         if ( bootargs )
         {
             res = fdt_property(kinfo->fdt, "bootargs", bootargs,
@@ -466,7 +469,7 @@ static int write_properties(struct domain *d, struct kernel_info *kinfo,
          * If the bootloader provides an initrd, we must create a placeholder
          * for the initrd properties. The values will be replaced later.
          */
-        if ( bootinfo.modules.module[MOD_INITRD].size )
+        if ( mod && mod->size )
         {
             u64 a = 0;
             res = fdt_property(kinfo->fdt, "linux,initrd-start", &a, sizeof(a));
@@ -1221,18 +1224,21 @@ static void dtb_load(struct kernel_info *kinfo)
 
 static void initrd_load(struct kernel_info *kinfo)
 {
+    struct bootmodule *mod = boot_module_find_by_kind(BOOTMOD_RAMDISK);
     paddr_t load_addr = kinfo->initrd_paddr;
-    paddr_t paddr = bootinfo.modules.module[MOD_INITRD].start;
-    paddr_t len = bootinfo.modules.module[MOD_INITRD].size;
+    paddr_t paddr, len;
     unsigned long offs;
     int node;
     int res;
     __be32 val[2];
     __be32 *cellp;
 
-    if ( !len )
+    if ( !mod || !mod->size )
         return;
 
+    paddr = mod->start;
+    len = mod->size;
+
     printk("Loading dom0 initrd from %"PRIpaddr" to 0x%"PRIpaddr"-0x%"PRIpaddr"\n",
            paddr, load_addr, load_addr + len);
 

diff --git a/xen/arch/arm/kernel.c b/xen/arch/arm/kernel.c
index ce5b95aaa636bb547ea588a9828bb59deeed16ea..230ff8ff7b2cc3dc8ad4b6d3422409a84bd112e2 100644 (file)
--- a/xen/arch/arm/kernel.c
+++ b/xen/arch/arm/kernel.c
@@ -68,8 +68,8 @@ static void place_modules(struct kernel_info *info,
                           paddr_t kernbase, paddr_t kernend)
 {
     /* Align DTB and initrd size to 2Mb. Linux only requires 4 byte alignment */
-    const paddr_t initrd_len =
-        ROUNDUP(bootinfo.modules.module[MOD_INITRD].size, MB(2));
+    const struct bootmodule *mod = boot_module_find_by_kind(BOOTMOD_RAMDISK);
+    const paddr_t initrd_len = ROUNDUP(mod ? mod->size : 0, MB(2));
     const paddr_t dtb_len = ROUNDUP(fdt_totalsize(info->fdt), MB(2));
     const paddr_t modsize = initrd_len + dtb_len;
 
@@ -372,20 +372,21 @@ err:
 
 int kernel_probe(struct kernel_info *info)
 {
+    struct bootmodule *mod = boot_module_find_by_kind(BOOTMOD_KERNEL);
     int rc;
 
     paddr_t start, size;
 
-    start = bootinfo.modules.module[MOD_KERNEL].start;
-    size = bootinfo.modules.module[MOD_KERNEL].size;
-
-    if ( !size )
+    if ( !mod || !mod->size )
     {
         printk(XENLOG_ERR "Missing kernel boot module?\n");
         return -ENOENT;
     }
 
-    printk("Loading kernel from boot module %d\n", MOD_KERNEL);
+    start = mod->start;
+    size = mod->size;
+
+    printk("Loading kernel from boot module @ %"PRIpaddr"\n", start);
 
 #ifdef CONFIG_ARM_64
     rc = kernel_zimage64_probe(info, start, size);

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index eefb6105606094feaa49b96b5491538a96239001..0cbe55233cd53e59d324a34847f840bf5b319e1d 100644 (file)
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -183,17 +183,58 @@ static void dt_unreserved_regions(paddr_t s, paddr_t e,
     cb(s, e);
 }
 
+struct bootmodule *add_boot_module(bootmodule_kind kind,
+                                   paddr_t start, paddr_t size,
+                                   const char *cmdline)
+{
+    struct bootmodules *mods = &bootinfo.modules;
+    struct bootmodule *mod;
+
+    if ( mods->nr_mods == MAX_MODULES )
+    {
+        printk("Ignoring %s boot module at %"PRIpaddr"-%"PRIpaddr" (too many)\n",
+               boot_module_kind_as_string(kind), start, start + size);
+        return NULL;
+    }
+
+    mod = &mods->module[mods->nr_mods++];
+    mod->kind = kind;
+    mod->start = start;
+    mod->size = size;
+    if ( cmdline )
+        safe_strcpy(mod->cmdline, cmdline);
+    else
+        mod->cmdline[0] = 0;
+
+    return mod;
+}
+
+struct bootmodule * __init boot_module_find_by_kind(bootmodule_kind kind)
+{
+    struct bootmodules *mods = &bootinfo.modules;
+    struct bootmodule *mod;
+    int i;
+    for (i = 0 ; i < mods->nr_mods ; i++ )
+    {
+        mod = &mods->module[i];
+        if ( mod->kind == kind )
+            return mod;
+    }
+    return NULL;
+}
+
 void __init discard_initial_modules(void)
 {
     struct bootmodules *mi = &bootinfo.modules;
     int i;
 
-    for ( i = MOD_DISCARD_FIRST; i <= mi->nr_mods; i++ )
+    for ( i = 0; i <= mi->nr_mods; i++ )
     {
         paddr_t s = mi->module[i].start;
         paddr_t e = s + PAGE_ALIGN(mi->module[i].size);
 
-        dt_unreserved_regions(s, e, init_domheap_pages, 0);
+        if ( mi->module[i].kind != BOOTMOD_XEN )
+            dt_unreserved_regions(s, e, init_domheap_pages, 0);
     }
 
     mi->nr_mods = 0;
@@ -335,7 +376,7 @@ static paddr_t __init get_xen_paddr(void)
         if ( bank->size >= min_size )
         {
             e = consider_modules(bank->start, bank->start + bank->size,
-                                 min_size, XEN_PADDR_ALIGN, 1);
+                                 min_size, XEN_PADDR_ALIGN, 0);
             if ( !e )
                 continue;
 
@@ -360,9 +401,6 @@ static paddr_t __init get_xen_paddr(void)
     printk("Placing Xen at 0x%"PRIpaddr"-0x%"PRIpaddr"\n",
            paddr, paddr + min_size);
 
-    bootinfo.modules.module[MOD_XEN].start = paddr;
-    bootinfo.modules.module[MOD_XEN].size = min_size;
-
     return paddr;
 }
 
@@ -665,7 +703,9 @@ void __init start_xen(unsigned long boot_phys_offset,
 {
     size_t fdt_size;
     int cpus, i;
+    paddr_t xen_paddr;
     const char *cmdline;
+    struct bootmodule *xen_bootmodule;
     struct domain *dom0;
 
     setup_cache();
@@ -690,7 +730,21 @@ void __init start_xen(unsigned long boot_phys_offset,
     printk("Command line: %s\n", cmdline);
     cmdline_parse(cmdline);
 
-    setup_pagetables(boot_phys_offset, get_xen_paddr());
+    /* Register Xen's load address as a boot module. */
+    xen_bootmodule = add_boot_module(BOOTMOD_XEN,
+                             (paddr_t)(uintptr_t)(_start + boot_phys_offset),
+                             (paddr_t)(uintptr_t)(_end - _start + 1), NULL);
+    BUG_ON(!xen_bootmodule);
+
+    xen_paddr = get_xen_paddr();
+    setup_pagetables(boot_phys_offset, xen_paddr);
+
+    /* Update Xen's address now that we have relocated. */
+    printk("Update BOOTMOD_XEN from %"PRIpaddr"-%"PRIpaddr" => %"PRIpaddr"-%"PRIpaddr"\n",
+           xen_bootmodule->start, xen_bootmodule->start + xen_bootmodule->size,
+           xen_paddr, xen_paddr + xen_bootmodule->size);
+    xen_bootmodule->start = xen_paddr;
+
     setup_mm(fdt_paddr, fdt_size);
 
     vm_init();

diff --git a/xen/include/asm-arm/setup.h b/xen/include/asm-arm/setup.h
index 85aa866430682c9b27999c244167c040af6a14c3..e2e18c30335df7dec32dae6978b81818b6104f32 100644 (file)
--- a/xen/include/asm-arm/setup.h
+++ b/xen/include/asm-arm/setup.h
@@ -5,14 +5,17 @@
 
 #define NR_MEM_BANKS 8
 
-#define MOD_XEN    0
-#define MOD_FDT    1
-#define MOD_KERNEL 2
-#define MOD_INITRD 3
-#define MOD_XSM    4
-#define NR_MODULES 5
+#define MAX_MODULES 5 /* Current maximum useful modules */
+
+typedef enum {
+    BOOTMOD_XEN,
+    BOOTMOD_FDT,
+    BOOTMOD_KERNEL,
+    BOOTMOD_RAMDISK,
+    BOOTMOD_XSM,
+    BOOTMOD_UNKNOWN
+}  bootmodule_kind;
 
-#define MOD_DISCARD_FIRST MOD_FDT
 
 struct membank {
     paddr_t start;
@@ -24,16 +27,17 @@ struct meminfo {
     struct membank bank[NR_MEM_BANKS];
 };
 
+#define BOOTMOD_MAX_CMDLINE 1024
 struct bootmodule {
+    bootmodule_kind kind;
     paddr_t start;
     paddr_t size;
-    char cmdline[1024];
+    char cmdline[BOOTMOD_MAX_CMDLINE];
 };
 
 struct bootmodules {
     int nr_mods;
-    /* Module 0 is Xen itself, followed by the provided modules-proper */
-    struct bootmodule module[NR_MODULES];
+    struct bootmodule module[MAX_MODULES];
 };
 
 struct bootinfo {
@@ -56,6 +60,11 @@ void discard_initial_modules(void);
 size_t __init boot_fdt_info(const void *fdt, paddr_t paddr);
 const char __init *boot_fdt_cmdline(const void *fdt);
 
+struct bootmodule *add_boot_module(bootmodule_kind kind,
+                                   paddr_t start, paddr_t size,
+                                   const char *cmdline);
+struct bootmodule *boot_module_find_by_kind(bootmodule_kind kind);
+
 #endif
 /*
  * Local variables:

diff --git a/xen/xsm/xsm_policy.c b/xen/xsm/xsm_policy.c
index a0dee09c4405c5e0e398629c0d7611e49532eb29..6e0bb78df4c7307b4c800089055114d57bd2265a 100644 (file)
--- a/xen/xsm/xsm_policy.c
+++ b/xen/xsm/xsm_policy.c
@@ -77,13 +77,16 @@ int __init xsm_multiboot_policy_init(unsigned long *module_map,
 #ifdef HAS_DEVICE_TREE
 int __init xsm_dt_policy_init(void)
 {
-    paddr_t paddr = early_info.modules.module[MOD_XSM].start;
-    paddr_t len = early_info.modules.module[MOD_XSM].size;
+    struct bootmodule *mod = boot_module_find_by_kind(BOOTMOD_XSM);
+    paddr_t paddr, len;
     xsm_magic_t magic;
 
-    if ( !len )
+    if ( !mod || !mod->size )
         return 0;
 
+    paddr = mod->start;
+    len = mod->size;
+
     copy_from_paddr(&magic, paddr, sizeof(magic));
 
     if ( magic != XSM_MAGIC )
@@ -106,3 +109,13 @@ int __init xsm_dt_policy_init(void)
     return 0;
 }
 #endif
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */