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| author | Keir Fraser <keir.fraser@citrix.com> | 2009-12-17 06:27:56 +0000 |
|---|---|---|
| committer | Keir Fraser <keir.fraser@citrix.com> | 2009-12-17 06:27:56 +0000 |
| commit | af909e7e16dd67452bde91bb71c8111c95c43983 (patch) | |
| tree | adc7949938cde5c9257942cb7fbbf6a06af08cfc /xen/include/asm-x86/mm.h | |
| parent | e8a90e0ab12cfb9cb4f8a87a5525797719cd07b6 (diff) | |
| download | xen-af909e7e16dd67452bde91bb71c8111c95c43983.tar.gz xen-af909e7e16dd67452bde91bb71c8111c95c43983.tar.bz2 xen-af909e7e16dd67452bde91bb71c8111c95c43983.zip | |
M2P translation cannot be handled through flat table with only one slot per MFN
when an MFN is shared. However, all existing calls can either infer the GFN (for
example p2m table destructor) or will not need to know GFN for shared pages.
This patch identifies and fixes all the M2P accessors, either by removing the
translation altogether or by making the relevant modifications. Shared MFNs have
a special value of SHARED_M2P_ENTRY stored in their M2P table slot.
Signed-off-by: Grzegorz Milos <Grzegorz.Milos@citrix.com>
Diffstat (limited to 'xen/include/asm-x86/mm.h')
| -rw-r--r-- | xen/include/asm-x86/mm.h | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/xen/include/asm-x86/mm.h b/xen/include/asm-x86/mm.h index b0c5bb1b8f..5c3ab88c3a 100644 --- a/xen/include/asm-x86/mm.h +++ b/xen/include/asm-x86/mm.h @@ -438,15 +438,27 @@ TYPE_SAFE(unsigned long,mfn); #define machine_to_phys_mapping ((unsigned long *)RDWR_MPT_VIRT_START) #define INVALID_M2P_ENTRY (~0UL) #define VALID_M2P(_e) (!((_e) & (1UL<<(BITS_PER_LONG-1)))) +#define SHARED_M2P_ENTRY (~0UL - 1UL) +#define SHARED_M2P(_e) ((_e) == SHARED_M2P_ENTRY) #ifdef CONFIG_COMPAT #define compat_machine_to_phys_mapping ((unsigned int *)RDWR_COMPAT_MPT_VIRT_START) -#define set_gpfn_from_mfn(mfn, pfn) \ +#define set_gpfn_from_mfn(mfn, pfn) ({ \ + struct domain *d = page_get_owner(__mfn_to_page(mfn)); \ + unsigned long entry = (d && (d == dom_cow)) ? \ + SHARED_M2P_ENTRY : (pfn); \ ((void)((mfn) >= (RDWR_COMPAT_MPT_VIRT_END - RDWR_COMPAT_MPT_VIRT_START) / 4 || \ - (compat_machine_to_phys_mapping[(mfn)] = (unsigned int)(pfn))), \ - machine_to_phys_mapping[(mfn)] = (pfn)) + (compat_machine_to_phys_mapping[(mfn)] = (unsigned int)(entry))), \ + machine_to_phys_mapping[(mfn)] = (entry)); \ + }) #else -#define set_gpfn_from_mfn(mfn, pfn) (machine_to_phys_mapping[(mfn)] = (pfn)) +#define set_gpfn_from_mfn(mfn, pfn) ({ \ + struct domain *d = page_get_owner(__mfn_to_page(mfn)); \ + if(d && (d == dom_cow)) \ + machine_to_phys_mapping[(mfn)] = SHARED_M2P_ENTRY; \ + else \ + machine_to_phys_mapping[(mfn)] = (pfn); \ + }) #endif #define get_gpfn_from_mfn(mfn) (machine_to_phys_mapping[(mfn)]) |