Check for a node in the device tree compatible with "xen,xen", if it is present set xen_domain_type to XEN_HVM_DOMAIN and continue initialization.
Map the real shared info page using XENMEM_add_to_physmap with XENMAPSPACE_shared_info.
Changes in v3:
- use the "xen,xen" notation rather than "arm,xen"; - add an additional check on the presence of the Xen version.
Changes in v2:
- replace pr_info with pr_debug.
Signed-off-by: Stefano Stabellini stefano.stabellini@eu.citrix.com --- arch/arm/xen/enlighten.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 61 insertions(+), 0 deletions(-)
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index c535540..78ea1f7 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -5,6 +5,9 @@ #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> #include <linux/module.h> +#include <linux/of.h> +#include <linux/of_irq.h> +#include <linux/of_address.h>
struct start_info _xen_start_info; struct start_info *xen_start_info = &_xen_start_info; @@ -33,3 +36,61 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma, return -ENOSYS; } EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range); + +/* + * see Documentation/devicetree/bindings/arm/xen.txt for the + * documentation of the Xen Device Tree format. + */ +static int __init xen_guest_init(void) +{ + struct xen_add_to_physmap xatp; + static struct shared_info *shared_info_page = 0; + struct device_node *node; + int len; + const char *s = NULL; + const char *version = NULL; + const char *xen_prefix = "xen,xen-"; + + node = of_find_compatible_node(NULL, NULL, "xen,xen"); + if (!node) { + pr_debug("No Xen support\n"); + return 0; + } + s = of_get_property(node, "compatible", &len); + if (strlen(s) + strlen(xen_prefix) + 1 < len && + !strncmp(xen_prefix, s + strlen(s) + 1, strlen(xen_prefix))) + version = s + strlen(s) + strlen(xen_prefix) + 1; + if (version == NULL) { + pr_debug("Xen version not found\n"); + return 0; + } + xen_domain_type = XEN_HVM_DOMAIN; + + if (!shared_info_page) + shared_info_page = (struct shared_info *) + get_zeroed_page(GFP_KERNEL); + if (!shared_info_page) { + pr_err("not enough memory\n"); + return -ENOMEM; + } + xatp.domid = DOMID_SELF; + xatp.idx = 0; + xatp.space = XENMAPSPACE_shared_info; + xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT; + if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) + BUG(); + + HYPERVISOR_shared_info = (struct shared_info *)shared_info_page; + + /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info + * page, we use it in the event channel upcall and in some pvclock + * related functions. We don't need the vcpu_info placement + * optimizations because we don't use any pv_mmu or pv_irq op on + * HVM. + * The shared info contains exactly 1 CPU (the boot CPU). The guest + * is required to use VCPUOP_register_vcpu_info to place vcpu info + * for secondary CPUs as they are brought up. */ + per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0]; + return 0; +} +core_initcall(xen_guest_init);