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| author |   David Vrabel <david.vrabel@citrix.com> | 2014-07-11 16:42:34 +0100 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2014-07-30 14:22:47 +0100 |
| commit | b7dd0e350e0bd4c0fddcc9b8958342700b00b168 (patch) | |
| tree | f69ea88b9e9f5e234d5c5d2f3f0ceaa22d3049b8 /drivers/firewire | |
| parent | xen/balloon: set ballooned out pages as invalid in p2m (diff) | |
| download | linux-dev-b7dd0e350e0bd4c0fddcc9b8958342700b00b168.tar.xz linux-dev-b7dd0e350e0bd4c0fddcc9b8958342700b00b168.zip | |
x86/xen: safely map and unmap grant frames when in atomic context
arch_gnttab_map_frames() and arch_gnttab_unmap_frames() are called in
atomic context but were calling alloc_vm_area() which might sleep.
Also, if a driver attempts to allocate a grant ref from an interrupt
and the table needs expanding, then the CPU may already by in lazy MMU
mode and apply_to_page_range() will BUG when it tries to re-enable
lazy MMU mode.
These two functions are only used in PV guests.
Introduce arch_gnttab_init() to allocates the virtual address space in
advance.
Avoid the use of apply_to_page_range() by using saving and using the
array of PTE addresses from the alloc_vm_area() call (which ensures
that the required page tables are pre-allocated).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/firewire')
0 files changed, 0 insertions, 0 deletions