linux-kernel - [PATCH v3 07/25] xen/arm: Xen detection and shared

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1345131377-14713-7-git-send-email-stefano.stabellini@eu.citrix.com>
Date:	Thu, 16 Aug 2012 16:35:59 +0100
From:	Stefano Stabellini <stefano.stabellini@...citrix.com>
To:	<linux-kernel@...r.kernel.org>
CC:	<xen-devel@...ts.xensource.com>,
	<Stefano.Stabellini@...citrix.com>, <konrad.wilk@...cle.com>,
	<tim@....org>, <Ian.Campbell@...rix.com>,
	<linux-arm-kernel@...ts.infradead.org>,
	<linaro-dev@...ts.linaro.org>, <catalin.marinas@....com>,
	<arnd@...db.de>,
	Stefano Stabellini <stefano.stabellini@...citrix.com>
Subject: [PATCH v3 07/25] xen/arm: Xen detection and shared_info page mapping

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@...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);
-- 
1.7.2.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/