From 81665f8e30850363ad08bb457a2ab6212069a03a Mon Sep 17 00:00:00 2001 From: Emmanuel Ackaouy Date: Fri, 23 Feb 2007 12:58:20 +0000 Subject: [PATCH] [XEN] [TOOLS] 32on64 compat save/restore: unadjust L3E flags at save time Get rid of USER|RW|ACCESSED L3 PTE flags which may be present in a PAE guest when running on a 64bit hypervisor at save time. This prevents the restore operation from getting confused by these flags. Reset disallowed L3E flags to match PAE case. Signed-off-by: Emmanuel Ackaouy --- tools/libxc/xc_linux_save.c | 12 ++++++++++++ xen/include/asm-x86/x86_64/page.h | 2 +- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/tools/libxc/xc_linux_save.c b/tools/libxc/xc_linux_save.c index 8930b9fc3c..35a5a5cd55 100644 --- a/tools/libxc/xc_linux_save.c +++ b/tools/libxc/xc_linux_save.c @@ -543,6 +543,18 @@ static int canonicalize_pagetable(unsigned long type, unsigned long pfn, pte &= ~MADDR_MASK_X86; pte |= (uint64_t)pfn << PAGE_SHIFT; + + /* + * PAE guest L3Es can contain these flags when running on + * a 64bit hypervisor. We zap these here to avoid any + * surprise at restore time... + */ + if ( pt_levels == 3 && + type == XEN_DOMCTL_PFINFO_L3TAB && + pte & (_PAGE_USER|_PAGE_RW|_PAGE_ACCESSED) ) + { + pte &= ~(_PAGE_USER|_PAGE_RW|_PAGE_ACCESSED); + } } if (pt_levels == 2) diff --git a/xen/include/asm-x86/x86_64/page.h b/xen/include/asm-x86/x86_64/page.h index 2cd376a5b3..18ec956d14 100644 --- a/xen/include/asm-x86/x86_64/page.h +++ b/xen/include/asm-x86/x86_64/page.h @@ -98,7 +98,7 @@ typedef l4_pgentry_t root_pgentry_t; #define L3_DISALLOW_MASK (BASE_DISALLOW_MASK) #define L4_DISALLOW_MASK (BASE_DISALLOW_MASK) -#define COMPAT_L3_DISALLOW_MASK L3_DISALLOW_MASK +#define COMPAT_L3_DISALLOW_MASK 0xFFFFF1E6U #define PAGE_HYPERVISOR (__PAGE_HYPERVISOR | _PAGE_GLOBAL) #define PAGE_HYPERVISOR_NOCACHE (__PAGE_HYPERVISOR_NOCACHE | _PAGE_GLOBAL) -- 2.30.2