linux/arch/x86/xen
David Vrabel 162e371712 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.

N.B. 'alloc_vm_area' pre-allocates the pagetable so there is no need
to worry about having to do a PGD/PUD/PMD walk (like apply_to_page_range
does) and we can instead do set_pte.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
----
[v2: Add comment about alloc_vm_area]
[v3: Fix compile error found by 0-day bot]
2014-07-14 15:28:02 -04:00
..
Kconfig Support PCI devices with multiple MSIs, performance improvement for 2014-04-03 14:01:37 -07:00
Makefile xen/x86: Implement x86_apic_ops 2012-05-01 14:50:33 -04:00
apic.c xen/apic/xenbus/swiotlb/pcifront/grant/tmem: Make functions or variables static. 2012-08-21 14:50:03 -04:00
debugfs.c debugfs: Add support to print u32 array in debugfs 2012-04-17 00:18:36 -04:00
debugfs.h debugfs: Add support to print u32 array in debugfs 2012-04-17 00:18:36 -04:00
enlighten.c xen: Introduce 'xen_nopv' to disable PV extensions for HVM guests. 2014-07-14 12:21:59 -04:00
grant-table.c x86/xen: safely map and unmap grant frames when in atomic context 2014-07-14 15:28:02 -04:00
irq.c asmlinkage, x86: Add explicit __visible to arch/x86/* 2014-05-05 16:07:44 -07:00
mmu.c Merge branch 'x86/vdso' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next 2014-06-05 08:05:29 -07:00
mmu.h xen: make a pile of mmu pvop functions static 2011-05-20 14:25:24 -07:00
multicalls.c xen/multicall: move *idx fields to start of mc_buffer 2011-07-18 15:43:46 -07:00
multicalls.h xen: use this_cpu_xxx replace percpu_xxx funcs 2012-01-24 12:20:24 -05:00
p2m.c x86/xen: set regions above the end of RAM as 1:1 2014-05-15 16:15:18 +01:00
pci-swiotlb-xen.c pci-swiotlb-xen: call pci_request_acs only ifdef CONFIG_PCI 2013-11-08 15:21:44 -05:00
platform-pci-unplug.c xen/pvhvm: Remove the xen_platform_pci int. 2014-01-03 14:54:53 -05:00
setup.c xen: regression and PVH fixes for 3.16-rc1 2014-06-19 07:53:27 -10:00
smp.c x86/xen: Fix 32-bit PV guests's usage of kernel_stack 2014-04-15 15:00:14 +01:00
smp.h xen: Clean up apic ipi interface 2013-05-29 09:04:21 -04:00
spinlock.c xen/spinlock: Don't enable them unconditionally. 2014-04-15 17:41:28 +01:00
suspend.c xen: refactor suspend pre/post hooks 2014-05-12 17:19:56 +01:00
time.c xen/x86: set VIRQ_TIMER priority to maximum 2014-01-06 10:07:55 -05:00
trace.c xen/trace: Fix compile error when CONFIG_XEN_PRIVILEGED_GUEST is not set 2011-08-05 09:43:02 -04:00
vdso.h
vga.c xen/vga: add the xen EFI video mode support 2012-09-24 09:28:57 -04:00
xen-asm.S xen: correctly check for pending events when restoring irq flags 2012-04-27 16:04:21 -04:00
xen-asm.h
xen-asm_32.S x86/xen: Fix 32-bit PV guests's usage of kernel_stack 2014-04-15 15:00:14 +01:00
xen-asm_64.S xen: use iret for return from 64b kernel to 32b usermode 2009-12-03 11:14:54 -08:00
xen-head.S xen/pvh: Support ParaVirtualized Hardware extensions (v3). 2014-01-06 10:44:24 -05:00
xen-ops.h x86/xen: fix memory setup for PVH dom0 2014-06-05 14:22:27 +01:00