[PATCH v4 07/24] xen/arm: Xen detection and shared_info page mapping
From: Konrad Rzeszutek Wilk <hidden>
Date: 2012-09-14 13:19:10
Also in:
lkml, xen-devel
On Fri, Sep 14, 2012 at 12:13:09PM +0100, Stefano Stabellini wrote:
quoted hunk ↗ jump to hunk
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 v4: - simpler parsing of Xen version in the compatible DT node. 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 <redacted> --- 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..6a0217d 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(xen_prefix) + 3 < len && + !strncmp(xen_prefix, s, strlen(xen_prefix)))
If we have version '4.3.1' won't this trip us over? Or if we only have 'major' and 'minor', then won't '4.11' trip us over too?
+ version = s + strlen(xen_prefix);
+ 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);
--
1.7.2.5