[PATCH v6 08/26] xen/arm: probe domU kernels and initrds

[Stefano Stabellini <sstabellini@kernel.org>]

Find addresses, sizes on device tree from kernel_probe.
Find the cmdline from the bootcmdlines array.

Introduce a new boot_module_find_by_addr_and_kind function to match not
just on boot module kind, but also by address so that we can support
multiple domains.

Introduce a boot_cmdline_find_by_name function to find the right struct
cmdline based on the device tree node name of the "xen,domain"
compatible node.

Set command line for dom0 in kernel_probe for consistency.

Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>
---
Changes in v6:
- style improvement in comment
- remove redundant cmdline assignment in construct_dom0

Changes in v5:
- constify kernel_probe
- add ASSERT and comment in kernel_probe
- limit variable scope
- fix printk message
- int/unsigned int
- set cmdline for dom0 too
- improve code readability

Changes in v3:
- retrieve cmdline from bootcmdlines array

Changes in v2:
- fix indentation
- unify kernel_probe with kernel_probe_domU
- find cmdline on device_tree from kernel_probe
---
 xen/arch/arm/domain_build.c |  4 +--
 xen/arch/arm/kernel.c       | 64 ++++++++++++++++++++++++++++++++++++++++-----
 xen/arch/arm/kernel.h       |  2 +-
 xen/arch/arm/setup.c        | 31 ++++++++++++++++++++++
 xen/include/asm-arm/setup.h |  3 +++
 5 files changed, 93 insertions(+), 11 deletions(-)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 6b15bc7..59c9f34 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2107,7 +2107,6 @@ static void __init find_gnttab_region(struct domain *d,
 
 int __init construct_dom0(struct domain *d)
 {
-    const struct bootcmdline *kernel = boot_cmdline_find_by_kind(BOOTMOD_KERNEL);
     struct kernel_info kinfo = {};
     struct vcpu *saved_current;
     int rc, i, cpu;
@@ -2135,7 +2134,7 @@ int __init construct_dom0(struct domain *d)
     kinfo.unassigned_mem = dom0_mem;
     kinfo.d = d;
 
-    rc = kernel_probe(&kinfo);
+    rc = kernel_probe(&kinfo, NULL);
     if ( rc < 0 )
         return rc;
 
@@ -2153,7 +2152,6 @@ int __init construct_dom0(struct domain *d)
 
 #endif
 
-    kinfo.cmdline = (kernel != NULL) ? &kernel->cmdline[0] : NULL;
     allocate_memory(d, &kinfo);
     find_gnttab_region(d, &kinfo);
 
diff --git a/xen/arch/arm/kernel.c b/xen/arch/arm/kernel.c
index da8410e..d6c810b 100644
--- a/xen/arch/arm/kernel.c
+++ b/xen/arch/arm/kernel.c
@@ -421,22 +421,72 @@ static int __init kernel_zimage32_probe(struct kernel_info *info,
     return 0;
 }
 
-int __init kernel_probe(struct kernel_info *info)
+int __init kernel_probe(struct kernel_info *info,
+                        const struct dt_device_node *domain)
 {
-    struct bootmodule *mod = boot_module_find_by_kind(BOOTMOD_KERNEL);
+    struct bootmodule *mod = NULL;
+    struct bootcmdline *cmd = NULL;
+    struct dt_device_node *node;
+    u64 kernel_addr, initrd_addr, size;
     int rc;
 
+    /* domain is NULL only for the hardware domain */
+    if ( domain == NULL )
+    {
+        ASSERT(is_hardware_domain(info->d));
+
+        mod = boot_module_find_by_kind(BOOTMOD_KERNEL);
+
+        info->kernel_bootmodule = mod;
+        info->initrd_bootmodule = boot_module_find_by_kind(BOOTMOD_RAMDISK);
+
+        cmd = boot_cmdline_find_by_kind(BOOTMOD_KERNEL);
+        if ( cmd )
+            info->cmdline = &cmd->cmdline[0];
+    }
+    else
+    {
+        const char *name = NULL;
+
+        dt_for_each_child_node(domain, node)
+        {
+            if ( dt_device_is_compatible(node, "multiboot,kernel") )
+            {
+                u32 len;
+                const __be32 *val;
+
+                val = dt_get_property(node, "reg", &len);
+                dt_get_range(&val, node, &kernel_addr, &size);
+                mod = boot_module_find_by_addr_and_kind(
+                        BOOTMOD_KERNEL, kernel_addr);
+                info->kernel_bootmodule = mod;
+            }
+            else if ( dt_device_is_compatible(node, "multiboot,ramdisk") )
+            {
+                u32 len;
+                const __be32 *val;
+
+                val = dt_get_property(node, "reg", &len);
+                dt_get_range(&val, node, &initrd_addr, &size);
+                info->initrd_bootmodule = boot_module_find_by_addr_and_kind(
+                        BOOTMOD_RAMDISK, initrd_addr);
+            }
+            else
+                continue;
+        }
+        name = dt_node_name(domain);
+        cmd = boot_cmdline_find_by_name(name);
+        if ( cmd )
+            info->cmdline = &cmd->cmdline[0];
+    }
     if ( !mod || !mod->size )
     {
         printk(XENLOG_ERR "Missing kernel boot module?\n");
         return -ENOENT;
     }
 
-    info->kernel_bootmodule = mod;
-
-    printk("Loading kernel from boot module @ %"PRIpaddr"\n", mod->start);
-
-    info->initrd_bootmodule = boot_module_find_by_kind(BOOTMOD_RAMDISK);
+    printk("Loading Dom%d kernel from boot module @ %"PRIpaddr"\n",
+           info->d->domain_id, info->kernel_bootmodule->start);
     if ( info->initrd_bootmodule )
         printk("Loading ramdisk from boot module @ %"PRIpaddr"\n",
                info->initrd_bootmodule->start);
diff --git a/xen/arch/arm/kernel.h b/xen/arch/arm/kernel.h
index 39b7828..4320f72 100644
--- a/xen/arch/arm/kernel.h
+++ b/xen/arch/arm/kernel.h
@@ -55,7 +55,7 @@ struct kernel_info {
  *  ->type
  *  ->load hook, and sets loader specific variables ->zimage
  */
-int kernel_probe(struct kernel_info *info);
+int kernel_probe(struct kernel_info *info, const struct dt_device_node *domain);
 
 /*
  * Loads the kernel into guest RAM.
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index c69e872..dbba8f3 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -297,6 +297,37 @@ struct bootcmdline * __init boot_cmdline_find_by_kind(bootmodule_kind kind)
     return NULL;
 }
 
+struct bootcmdline * __init boot_cmdline_find_by_name(const char *name)
+{
+    struct bootcmdlines *mods = &bootinfo.cmdlines;
+    struct bootcmdline *mod;
+    unsigned int i;
+
+    for (i = 0 ; i < mods->nr_mods ; i++ )
+    {
+        mod = &mods->cmdline[i];
+        if ( strcmp(mod->dt_name, name) == 0 )
+            return mod;
+    }
+    return NULL;
+}
+
+struct bootmodule * __init boot_module_find_by_addr_and_kind(bootmodule_kind kind,
+                                                             paddr_t start)
+{
+    struct bootmodules *mods = &bootinfo.modules;
+    struct bootmodule *mod;
+    unsigned int i;
+
+    for (i = 0 ; i < mods->nr_mods ; i++ )
+    {
+        mod = &mods->module[i];
+        if ( mod->kind == kind && mod->start == start )
+            return mod;
+    }
+    return NULL;
+}
+
 const char * __init boot_module_kind_as_string(bootmodule_kind kind)
 {
     switch ( kind )
diff --git a/xen/include/asm-arm/setup.h b/xen/include/asm-arm/setup.h
index 3a30329..33fb04e 100644
--- a/xen/include/asm-arm/setup.h
+++ b/xen/include/asm-arm/setup.h
@@ -101,9 +101,12 @@ const char __init *boot_fdt_cmdline(const void *fdt);
 struct bootmodule *add_boot_module(bootmodule_kind kind,
                                    paddr_t start, paddr_t size, bool domU);
 struct bootmodule *boot_module_find_by_kind(bootmodule_kind kind);
+struct bootmodule * __init boot_module_find_by_addr_and_kind(bootmodule_kind kind,
+                                                             paddr_t start);
 void add_boot_cmdline(const char *name, const char *cmdline,
                       bootmodule_kind kind, bool domU);
 struct bootcmdline *boot_cmdline_find_by_kind(bootmodule_kind kind);
+struct bootcmdline * __init boot_cmdline_find_by_name(const char *name);
 const char * __init boot_module_kind_as_string(bootmodule_kind kind);
 
 #endif
-- 
1.9.1


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