[PATCH] vmi: fix highpte

Provide a PT map hook for HIGHPTE kernels to designate where they are mapping
page tables.  This information is required so the physical address of PTE
updates can be determined; otherwise, the mm layer would have to carry the
physical address all the way to each PTE modification callsite, which is even
more hideous that the macros required to provide the proper hooks.

So lets not mess up arch neutral code to achieve this, but keep the horror in
an #ifdef HIGHPTE in include/asm-i386/pgtable.h.  I had to use macros here
because some types are not yet defined in all the include paths for this
header.

This patch is absolutely required for HIGHPTE kernels to operate properly with
VMI.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 23 insertions, 4 deletions

diff --git a/include/asm-i386/paravirt.h b/include/asm-i386/paravirt.h
index a35c81480654..e01d895d7379 100644
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -131,6 +131,8 @@ struct paravirt_ops
         void (*flush_tlb_kernel)(void);
         void (*flush_tlb_single)(u32 addr);
 
+        void (fastcall *map_pt_hook)(int type, pte_t *va, u32 pfn);
+
         void (*alloc_pt)(u32 pfn);
         void (*alloc_pd)(u32 pfn);
         void (*alloc_pd_clone)(u32 pfn, u32 clonepfn, u32 start, u32 count);
@@ -354,6 +356,8 @@ static inline void startup_ipi_hook(int phys_apicid, unsigned long start_eip,
 #define __flush_tlb_global() paravirt_ops.flush_tlb_kernel()
 #define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr)
 
+#define paravirt_map_pt_hook(type, va, pfn) paravirt_ops.map_pt_hook(type, va, pfn)
+
 #define paravirt_alloc_pt(pfn) paravirt_ops.alloc_pt(pfn)
 #define paravirt_release_pt(pfn) paravirt_ops.release_pt(pfn)
 
diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h
index e6a4723f0eb1..c3b58d473a55 100644
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -263,6 +263,7 @@ static inline pte_t pte_mkhuge(pte_t pte)	{ (pte).pte_low |= _PAGE_PSE; return p
  */
 #define pte_update(mm, addr, ptep)              do { } while (0)
 #define pte_update_defer(mm, addr, ptep)        do { } while (0)
+#define paravirt_map_pt_hook(slot, va, pfn)     do { } while (0)
 #endif
 
 /*
@@ -469,10 +470,24 @@ extern pte_t *lookup_address(unsigned long address);
 #endif
 
 #if defined(CONFIG_HIGHPTE)
-#define pte_offset_map(dir, address) \
-        ((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE0) + pte_index(address))
-#define pte_offset_map_nested(dir, address) \
-        ((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE1) + pte_index(address))
+#define pte_offset_map(dir, address)                            \
+({                                                              \
+        pte_t *__ptep;                                          \
+        unsigned pfn = pmd_val(*(dir)) >> PAGE_SHIFT;           \
+        __ptep = (pte_t *)kmap_atomic(pfn_to_page(pfn),KM_PTE0);\
+        paravirt_map_pt_hook(KM_PTE0,__ptep, pfn);              \
+        __ptep = __ptep + pte_index(address);                   \
+        __ptep;                                                 \
+})
+#define pte_offset_map_nested(dir, address)                     \
+({                                                              \
+        pte_t *__ptep;                                          \
+        unsigned pfn = pmd_val(*(dir)) >> PAGE_SHIFT;           \
+        __ptep = (pte_t *)kmap_atomic(pfn_to_page(pfn),KM_PTE1);\
+        paravirt_map_pt_hook(KM_PTE1,__ptep, pfn);              \
+        __ptep = __ptep + pte_index(address);                   \
+        __ptep;                                                 \
+})
 #define pte_unmap(pte) kunmap_atomic(pte, KM_PTE0)
 #define pte_unmap_nested(pte) kunmap_atomic(pte, KM_PTE1)
 #else