Martin J. Bligh wrote:
>I can easily leave those bits out. There's going to be lots of bits common
>with std i386, and bits that are common amongst the hypervisor layers,
>then bits that are specific. Hopefully more bits that are common, but
>still.
>
>Humpf. I shall go back into my corner and have a rethink. Will read through
>your patches some more, then send you some email.
>
>
Pulling LKML this time. For the most part, I have encapsulated
everything Xen could possibly need from a CPU / page table / descriptor
table point of view. All privileged operations, all sensitive
operations, and all privileged data access.
The easiest way to probably go about this is find common code that we
share in this area and get our trees cleaned to that level. This leaves
behind the higher level operations. I have deliberately refrained from
introducing higher level operations and hints at this stage, because I
know they might require a bit of a rethink when the Xen picture becomes
more clear. It appears the first high level operations you have
provided are the set_page_writable / set_page_readonly hypervisor
interfaces, which I think are a great start. Since I haven't tried to
introduce these types of interfaces yet, you can expect very little
collision with the important bits in your tree. I think you'll find
going file by file through the low-level stuff will be quite easy, since
I've encapsulated for the most part the minimal superset of what Xen
could possibly need.
I do expect some issues with the MMU patches, the dual compile time PAE
/ non-PAE stuff throws a giant monkeywrench into the middle of the code
when trying to rework it for a hypervisor. I've attached my MMU patch
so you can take a look.
I do have patches for higher level interfaces that I will be sending
along to the virtualization list so we can get cohesion on the best
approach before moving forward with more hints and high level paradigms
to LKML.
Zach
-------------- next part --------------
i386 Transparent paravirtualization sub-arch patch #8.
Transparent paravirtualization support for MMU operations.
All operations which update live page table entries have been moved to the
sub-architecture layer. Unfortunately, this required yet another parallel set
of pgtable-Nlevel-ops.h files, but this avoids the ugliness of having to use
#ifdef's all of the code.
This is pure code motion. Anything else would be a bug.
Signed-off-by: Zachary Amsden <zach@xxxxxxxxxx>
Index: linux-2.6.13/include/asm-i386/pgtable-2level.h
===================================================================
--- linux-2.6.13.orig/include/asm-i386/pgtable-2level.h 2005-08-04 13:42:31.000000000 -0700
+++ linux-2.6.13/include/asm-i386/pgtable-2level.h 2005-08-04 14:02:16.000000000 -0700
@@ -8,17 +8,6 @@
#define pgd_ERROR(e) \
printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
-/*
- * Certain architectures need to do special things when PTEs
- * within a page table are directly modified. Thus, the following
- * hook is made available.
- */
-#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
-#define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval)
-#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
-
-#define ptep_get_and_clear(mm,addr,xp) __pte(xchg(&(xp)->pte_low, 0))
#define pte_same(a, b) ((a).pte_low == (b).pte_low)
#define pte_page(x) pfn_to_page(pte_pfn(x))
#define pte_none(x) (!(x).pte_low)
Index: linux-2.6.13/include/asm-i386/pgtable-3level.h
===================================================================
--- linux-2.6.13.orig/include/asm-i386/pgtable-3level.h 2005-08-04 13:42:31.000000000 -0700
+++ linux-2.6.13/include/asm-i386/pgtable-3level.h 2005-08-04 14:02:16.000000000 -0700
@@ -44,28 +44,6 @@
return pte_x(pte);
}
-/* Rules for using set_pte: the pte being assigned *must* be
- * either not present or in a state where the hardware will
- * not attempt to update the pte. In places where this is
- * not possible, use pte_get_and_clear to obtain the old pte
- * value and then use set_pte to update it. -ben
- */
-static inline void set_pte(pte_t *ptep, pte_t pte)
-{
- ptep->pte_high = pte.pte_high;
- smp_wmb();
- ptep->pte_low = pte.pte_low;
-}
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
-
-#define __HAVE_ARCH_SET_PTE_ATOMIC
-#define set_pte_atomic(pteptr,pteval) \
- set_64bit((unsigned long long *)(pteptr),pte_val(pteval))
-#define set_pmd(pmdptr,pmdval) \
- set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval))
-#define set_pud(pudptr,pudval) \
- (*(pudptr) = (pudval))
-
/*
* Pentium-II erratum A13: in PAE mode we explicitly have to flush
* the TLB via cr3 if the top-level pgd is changed...
@@ -90,18 +68,6 @@
#define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \
pmd_index(address))
-static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
-{
- pte_t res;
-
- /* xchg acts as a barrier before the setting of the high bits */
- res.pte_low = xchg(&ptep->pte_low, 0);
- res.pte_high = ptep->pte_high;
- ptep->pte_high = 0;
-
- return res;
-}
-
static inline int pte_same(pte_t a, pte_t b)
{
return a.pte_low == b.pte_low && a.pte_high == b.pte_high;
Index: linux-2.6.13/include/asm-i386/pgtable.h
===================================================================
--- linux-2.6.13.orig/include/asm-i386/pgtable.h 2005-08-04 13:47:07.000000000 -0700
+++ linux-2.6.13/include/asm-i386/pgtable.h 2005-08-04 14:02:29.000000000 -0700
@@ -201,11 +201,9 @@
extern unsigned long pg0[];
#define pte_present(x) ((x).pte_low & (_PAGE_PRESENT | _PAGE_PROTNONE))
-#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
#define pmd_none(x) (!pmd_val(x))
#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
-#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
@@ -243,20 +241,12 @@
#else
# include <asm/pgtable-2level.h>
#endif
+#include <pgtable-ops.h>
+
+#define set_pte_at(mm,addr,pteptr,pteval) set_pte(pteptr,pteval)
-static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
-{
- if (!pte_dirty(*ptep))
- return 0;
- return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte_low);
-}
-
-static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
-{
- if (!pte_young(*ptep))
- return 0;
- return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte_low);
-}
+#define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
+#define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm, unsigned long addr, pte_t *ptep, int full)
{
@@ -270,26 +260,6 @@
return pte;
}
-static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
-{
- clear_bit(_PAGE_BIT_RW, &ptep->pte_low);
-}
-
-/*
- * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
- *
- * dst - pointer to pgd range anwhere on a pgd page
- * src - ""
- * count - the number of pgds to copy.
- *
- * dst and src can be on the same page, but the range must not overlap,
- * and must not cross a page boundary.
- */
-static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
-{
- memcpy(dst, src, count * sizeof(pgd_t));
-}
-
/*
* Macro to mark a page protection value as "uncacheable". On processors which do not support
* it, this is a no-op.
@@ -414,14 +384,6 @@
* bit at the same time.
*/
#define update_mmu_cache(vma,address,pte) do { } while (0)
-#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
-#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
- do { \
- if (__dirty) { \
- (__ptep)->pte_low = (__entry).pte_low; \
- flush_tlb_page(__vma, __address); \
- } \
- } while (0)
#endif /* !__ASSEMBLY__ */
Index: linux-2.6.13/include/asm-i386/mach-default/pgtable-2level-ops.h
===================================================================
--- linux-2.6.13.orig/include/asm-i386/mach-default/pgtable-2level-ops.h 2005-08-04 14:02:04.000000000 -0700
+++ linux-2.6.13/include/asm-i386/mach-default/pgtable-2level-ops.h 2005-08-04 14:02:16.000000000 -0700
@@ -0,0 +1,15 @@
+#ifndef _MACH_PGTABLE_LEVEL_OPS_H
+#define _MACH_PGTABLE_LEVEL_OPS_H
+
+/*
+ * Certain architectures need to do special things when PTEs
+ * within a page table are directly modified. Thus, the following
+ * hook is made available.
+ */
+#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
+#define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval)
+#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
+
+#define ptep_get_and_clear(mm,addr,xp) __pte(xchg(&(xp)->pte_low, 0))
+
+#endif /* _PGTABLE_OPS_H */
Index: linux-2.6.13/include/asm-i386/mach-default/pgtable-3level-ops.h
===================================================================
--- linux-2.6.13.orig/include/asm-i386/mach-default/pgtable-3level-ops.h 2005-08-04 14:02:04.000000000 -0700
+++ linux-2.6.13/include/asm-i386/mach-default/pgtable-3level-ops.h 2005-08-04 14:02:16.000000000 -0700
@@ -0,0 +1,37 @@
+#ifndef _MACH_PGTABLE_LEVEL_OPS_H
+#define _MACH_PGTABLE_LEVEL_OPS_H
+
+/* Rules for using set_pte: the pte being assigned *must* be
+ * either not present or in a state where the hardware will
+ * not attempt to update the pte. In places where this is
+ * not possible, use pte_get_and_clear to obtain the old pte
+ * value and then use set_pte to update it. -ben
+ */
+static inline void set_pte(pte_t *ptep, pte_t pte)
+{
+ ptep->pte_high = pte.pte_high;
+ smp_wmb();
+ ptep->pte_low = pte.pte_low;
+}
+
+#define __HAVE_ARCH_SET_PTE_ATOMIC
+#define set_pte_atomic(pteptr,pteval) \
+ set_64bit((unsigned long long *)(pteptr),pte_val(pteval))
+#define set_pmd(pmdptr,pmdval) \
+ set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval))
+#define set_pud(pudptr,pudval) \
+ (*(pudptr) = (pudval))
+
+static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ pte_t res;
+
+ /* xchg acts as a barrier before the setting of the high bits */
+ res.pte_low = xchg(&ptep->pte_low, 0);
+ res.pte_high = ptep->pte_high;
+ ptep->pte_high = 0;
+
+ return res;
+}
+
+#endif
Index: linux-2.6.13/include/asm-i386/mach-default/pgtable-ops.h
===================================================================
--- linux-2.6.13.orig/include/asm-i386/mach-default/pgtable-ops.h 2005-08-04 14:02:04.000000000 -0700
+++ linux-2.6.13/include/asm-i386/mach-default/pgtable-ops.h 2005-08-04 14:02:44.000000000 -0700
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2005, VMware, Inc.
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Send feedback to zach@xxxxxxxxxx
+ *
+ */
+
+#ifndef _PGTABLE_OPS_H
+#define _PGTABLE_OPS_H
+
+#ifdef CONFIG_X86_PAE
+# include <pgtable-3level-ops.h>
+#else
+# include <pgtable-2level-ops.h>
+#endif
+
+static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
+{
+ if (!pte_dirty(*ptep))
+ return 0;
+ return test_and_clear_bit(_PAGE_BIT_DIRTY, &ptep->pte_low);
+}
+
+static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
+{
+ if (!pte_young(*ptep))
+ return 0;
+ return test_and_clear_bit(_PAGE_BIT_ACCESSED, &ptep->pte_low);
+}
+
+static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ clear_bit(_PAGE_BIT_RW, &ptep->pte_low);
+}
+
+/*
+ * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
+ *
+ * dst - pointer to pgd range anwhere on a pgd page
+ * src - ""
+ * count - the number of pgds to copy.
+ *
+ * dst and src can be on the same page, but the range must not overlap,
+ * and must not cross a page boundary.
+ */
+static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
+{
+ memcpy(dst, src, count * sizeof(pgd_t));
+}
+
+#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
+ do { \
+ if (__dirty) { \
+ (__ptep)->pte_low = (__entry).pte_low; \
+ flush_tlb_page(__vma, __address); \
+ } \
+ } while (0)
+
+#endif /* _PGTABLE_OPS_H */
