From 4cb90ae29a9c8615d7087773362062545f052d0f Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Thu, 2 Jul 2009 16:16:15 +0100 Subject: [PATCH] kexec: switch to a known good/static GDT before kexec kexec has been failing (at least on 32on64, didn't try others) since 18771:8e18dd41c6c7 "x86: reduce GDT switching". Ensure that we are using a known good GDT before attempting to switch to compatability mode. Signed-off-by: Ian Campbell --- xen/arch/x86/machine_kexec.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/xen/arch/x86/machine_kexec.c b/xen/arch/x86/machine_kexec.c index 7488834593..f44aba2b5b 100644 --- a/xen/arch/x86/machine_kexec.c +++ b/xen/arch/x86/machine_kexec.c @@ -113,6 +113,18 @@ void machine_reboot_kexec(xen_kexec_image_t *image) void machine_kexec(xen_kexec_image_t *image) { + struct desc_ptr gdt_desc = { + .base = (unsigned long)(boot_cpu_gdt_table - FIRST_RESERVED_GDT_ENTRY), + .limit = LAST_RESERVED_GDT_BYTE + }; + + /* + * compat_machine_kexec() returns to idle pagetables, which requires us + * to be running on a static GDT mapping (idle pagetables have no GDT + * mappings in their per-domain mapping area). + */ + asm volatile ( "lgdt %0" : : "m" (gdt_desc) ); + #ifdef CONFIG_COMPAT if ( is_pv_32on64_domain(dom0) ) { -- 2.30.2