diff options
| author | Zachary Amsden <zach@vmware.com> | 2006-09-30 23:29:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-01 00:39:34 -0700 |
| commit | 23002d88be309a7c78db69363c9d933a29a3b0bb (patch) | |
| tree | ecd99ef70c0f38ff81bf2e3c6d7caeed2b88b41e /include/asm-i386/pgtable.h | |
| parent | 25e4df5bae333a06cd2c9b88baf14432652dc9f7 (diff) | |
[PATCH] paravirt: kpte flush
Create a new PTE function which combines clearing a kernel PTE with the
subsequent flush. This allows the two to be easily combined into a single
hypercall or paravirt-op. More subtly, reverse the order of the flush for
kmap_atomic. Instead of flushing on establishing a mapping, flush on clearing
a mapping. This eliminates the possibility of leaving stale kmap entries
which may still have valid TLB mappings. This is required for direct mode
hypervisors, which need to reprotect all mappings of a given page when
changing the page type from a normal page to a protected page (such as a page
table or descriptor table page). But it also provides some nicer semantics
for real hardware, by providing extra debug-proofing against using stale
mappings, as well as ensuring that no stale mappings exist when changing the
cacheability attributes of a page, which could lead to cache conflicts when
two different types of mappings exist for the same page.
Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-i386/pgtable.h')
| -rw-r--r-- | include/asm-i386/pgtable.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/asm-i386/pgtable.h b/include/asm-i386/pgtable.h index 94c87ff4b5a..ee9696d2f67 100644 --- a/include/asm-i386/pgtable.h +++ b/include/asm-i386/pgtable.h @@ -441,6 +441,13 @@ extern pte_t *lookup_address(unsigned long address); #define pte_unmap_nested(pte) do { } while (0) #endif +/* Clear a kernel PTE and flush it from the TLB */ +#define kpte_clear_flush(ptep, vaddr) \ +do { \ + pte_clear(&init_mm, vaddr, ptep); \ + __flush_tlb_one(vaddr); \ +} while (0) + /* * The i386 doesn't have any external MMU info: the kernel page * tables contain all the necessary information. |