From: Jeremy Fitzhardinge <jeremy@xensource.com>
Date: Tue, 16 Oct 2007 18:51:31 +0000 (-0700)
Subject: xen: ask the hypervisor how much space it needs reserved
X-Git-Tag: v2.6.24-rc1~478^2~3
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb1d84043ca73212b08ff57608f51b372529e6d6;p=linux-2.6

xen: ask the hypervisor how much space it needs reserved

Ask the hypervisor how much space it needs reserved, since 32-on-64
doesn't need any space, and it may change in future.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
---

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 4186cb6a7f..bc7bf5f8d0 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1112,6 +1112,17 @@ static const struct machine_ops __initdata xen_machine_ops = {
 };
 
 
+static void __init xen_reserve_top(void)
+{
+	unsigned long top = HYPERVISOR_VIRT_START;
+	struct xen_platform_parameters pp;
+
+	if (HYPERVISOR_xen_version(XENVER_platform_parameters, &pp) == 0)
+		top = pp.virt_start;
+
+	reserve_top_address(-top + 2 * PAGE_SIZE);
+}
+
 /* First C function to be called on Xen boot */
 asmlinkage void __init xen_start_kernel(void)
 {
@@ -1169,7 +1180,7 @@ asmlinkage void __init xen_start_kernel(void)
 		pv_info.kernel_rpl = 0;
 
 	/* set the limit of our address space */
-	reserve_top_address(-HYPERVISOR_VIRT_START + 2 * PAGE_SIZE);
+	xen_reserve_top();
 
 	/* set up basic CPUID stuff */
 	cpu_detect(&new_cpu_data);