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authorJeremy Fitzhardinge <jeremy@goop.org>2008-05-26 18:31:27 -0400
committerThomas Gleixner <tglx@linutronix.de>2008-05-27 04:11:38 -0400
commit0e91398f2a5d4eb6b07df8115917d0d1cf3e9b58 (patch)
treec6a3b31b7bcbbfb55bb2304d8651abdd28cdad54 /drivers/xen/grant-table.c
parent7d88d32a4670af583c896e5ecd3929b78538ca62 (diff)
xen: implement save/restore
This patch implements Xen save/restore and migration. Saving is triggered via xenbus, which is polled in drivers/xen/manage.c. When a suspend request comes in, the kernel prepares itself for saving by: 1 - Freeze all processes. This is primarily to prevent any partially-completed pagetable updates from confusing the suspend process. If CONFIG_PREEMPT isn't defined, then this isn't necessary. 2 - Suspend xenbus and other devices 3 - Stop_machine, to make sure all the other vcpus are quiescent. The Xen tools require the domain to run its save off vcpu0. 4 - Within the stop_machine state, it pins any unpinned pgds (under construction or destruction), performs canonicalizes various other pieces of state (mostly converting mfns to pfns), and finally 5 - Suspend the domain Restore reverses the steps used to save the domain, ending when all the frozen processes are thawed. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers/xen/grant-table.c')
-rw-r--r--drivers/xen/grant-table.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 52b6b41b909d..e9e11168616a 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -471,14 +471,14 @@ static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
471 return 0; 471 return 0;
472} 472}
473 473
474static int gnttab_resume(void) 474int gnttab_resume(void)
475{ 475{
476 if (max_nr_grant_frames() < nr_grant_frames) 476 if (max_nr_grant_frames() < nr_grant_frames)
477 return -ENOSYS; 477 return -ENOSYS;
478 return gnttab_map(0, nr_grant_frames - 1); 478 return gnttab_map(0, nr_grant_frames - 1);
479} 479}
480 480
481static int gnttab_suspend(void) 481int gnttab_suspend(void)
482{ 482{
483 arch_gnttab_unmap_shared(shared, nr_grant_frames); 483 arch_gnttab_unmap_shared(shared, nr_grant_frames);
484 return 0; 484 return 0;