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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 /include/xen | |
| parent | fb9a0c443691ceaab3daba966bbbd9f5ff3aa26f (diff) | |
| download | op-kernel-dev-b7dd0e350e0bd4c0fddcc9b8958342700b00b168.zip op-kernel-dev-b7dd0e350e0bd4c0fddcc9b8958342700b00b168.tar.gz | |
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 'include/xen')
| -rw-r--r-- | include/xen/grant_table.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index a5af2a2..5c1aba1 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -170,6 +170,7 @@ gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr, unmap->dev_bus_addr = 0; } +int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status); int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes, unsigned long max_nr_gframes, void **__shared); |
