[Xen-changelog] [xen stable-4.4] x86/EFI: keep EFI runtime services top level page tables up-to-date

[patchbot@xxxxxxx]

commit 34b61e901f620e43b7638803cc8f25d53c7d1040
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu Jun 18 09:19:23 2015 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Jun 18 09:19:23 2015 +0200

    x86/EFI: keep EFI runtime services top level page tables up-to-date
    
    Updates to idle_pg_table[] need to be mirrored into the page tables
    used for invoking EFI runtime services.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    master commit: db83975f0fcd30370392ed288a7bd2420624ed4e
    master date: 2015-05-19 11:39:09 +0200
---
 xen/arch/x86/efi/runtime.c |    7 +++++++
 xen/arch/x86/efi/stub.c    |    3 +++
 xen/arch/x86/mm.c          |    5 ++++-
 xen/include/asm-x86/page.h |    1 +
 4 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/xen/arch/x86/efi/runtime.c b/xen/arch/x86/efi/runtime.c
index 7fd7431..441ec90 100644
--- a/xen/arch/x86/efi/runtime.c
+++ b/xen/arch/x86/efi/runtime.c
@@ -4,6 +4,7 @@
 #include <xen/guest_access.h>
 #include <xen/irq.h>
 #include <xen/time.h>
+#include <asm/atomic.h>
 #include <asm/mc146818rtc.h>
 
 DEFINE_XEN_GUEST_HANDLE(CHAR16);
@@ -45,6 +46,12 @@ l4_pgentry_t *__read_mostly efi_l4_pgtable;
 
 const struct efi_pci_rom *__read_mostly efi_pci_roms;
 
+void efi_update_l4_pgtable(unsigned int l4idx, l4_pgentry_t l4e)
+{
+    if ( efi_l4_pgtable )
+        l4e_write(efi_l4_pgtable + l4idx, l4e);
+}
+
 unsigned long efi_rs_enter(void)
 {
     static const u16 fcw = FCW_DEFAULT;
diff --git a/xen/arch/x86/efi/stub.c b/xen/arch/x86/efi/stub.c
index b8f49f8..627009f 100644
--- a/xen/arch/x86/efi/stub.c
+++ b/xen/arch/x86/efi/stub.c
@@ -2,6 +2,7 @@
 #include <xen/errno.h>
 #include <xen/init.h>
 #include <xen/lib.h>
+#include <asm/page.h>
 
 #ifndef efi_enabled
 const bool_t efi_enabled = 0;
@@ -9,6 +10,8 @@ const bool_t efi_enabled = 0;
 
 void __init efi_init_memory(void) { }
 
+void efi_update_l4_pgtable(unsigned int l4idx, l4_pgentry_t l4e) { }
+
 paddr_t efi_rs_page_table(void)
 {
     BUG();
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 088ce35..68cc33b 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5286,7 +5286,10 @@ static l3_pgentry_t *virt_to_xen_l3e(unsigned long v)
             spin_lock(&map_pgdir_lock);
         if ( !(l4e_get_flags(*pl4e) & _PAGE_PRESENT) )
         {
-            l4e_write(pl4e, l4e_from_paddr(__pa(pl3e), __PAGE_HYPERVISOR));
+            l4_pgentry_t l4e = l4e_from_paddr(__pa(pl3e), __PAGE_HYPERVISOR);
+
+            l4e_write(pl4e, l4e);
+            efi_update_l4_pgtable(l4_table_offset(v), l4e);
             pl3e = NULL;
         }
         if ( locking )
diff --git a/xen/include/asm-x86/page.h b/xen/include/asm-x86/page.h
index ccc268d..91e9e92 100644
--- a/xen/include/asm-x86/page.h
+++ b/xen/include/asm-x86/page.h
@@ -286,6 +286,7 @@ extern l2_pgentry_t l2_identmap[4*L2_PAGETABLE_ENTRIES];
 extern l1_pgentry_t l1_identmap[L1_PAGETABLE_ENTRIES],
     l1_fixmap[L1_PAGETABLE_ENTRIES];
 void paging_init(void);
+void efi_update_l4_pgtable(unsigned int l4idx, l4_pgentry_t);
 #endif /* !defined(__ASSEMBLY__) */
 
 #define _PAGE_NONE     _AC(0x000,U)
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.4

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