xen_mm_pin_all()/unpin_all() are used to implement full guest instance
suspend/restore. It's a stop-all method that needs to iterate through
all allocated pgds in the system to fix them up for Xen's use.
This code uses pgd_list, probably because it was an easy interface.
But we want to remove the pgd_list, so convert the code over to walk
all tasks in the system. This is an equivalent method.
(As I don't use Xen this is was only build tested.)
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Waiman Long <waiman.l...@hp.com>
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
arch/x86/xen/mmu.c | 34 ++++++++++++++++++++++++++++------
1 file changed, 28 insertions(+), 6 deletions(-)
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index dd151b2045b0..87a8354435f8 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -853,18 +853,29 @@ static void xen_pgd_pin(struct mm_struct *mm)
*/
void xen_mm_pin_all(void)
{
- struct page *page;
+ struct task_struct *g, *p;
+ rcu_read_lock();
spin_lock(&pgd_lock);
- list_for_each_entry(page, &pgd_list, lru) {
+ for_each_process_thread(g, p) {
+ struct page *page;
+ pgd_t *pgd;
+
+ if (!p->mm)
+ continue;
+
+ pgd = p->mm->pgd;
+ page = virt_to_page(pgd);
+
if (!PagePinned(page)) {
- __xen_pgd_pin(&init_mm, (pgd_t *)page_address(page));
+ __xen_pgd_pin(&init_mm, pgd);
SetPageSavePinned(page);
}
}
spin_unlock(&pgd_lock);
+ rcu_read_unlock();
}
/*
@@ -967,19 +978,30 @@ static void xen_pgd_unpin(struct mm_struct *mm)
*/
void xen_mm_unpin_all(void)
{
- struct page *page;
+ struct task_struct *g, *p;
+ rcu_read_lock();
spin_lock(&pgd_lock);
- list_for_each_entry(page, &pgd_list, lru) {
+ for_each_process_thread(g, p) {
+ struct page *page;
+ pgd_t *pgd;
+
+ if (!p->mm)
+ continue;
+
+ pgd = p->mm->pgd;
+ page = virt_to_page(pgd);
+
if (PageSavePinned(page)) {
BUG_ON(!PagePinned(page));
- __xen_pgd_unpin(&init_mm, (pgd_t *)page_address(page));
+ __xen_pgd_unpin(&init_mm, pgd);
ClearPageSavePinned(page);
}
}
spin_unlock(&pgd_lock);
+ rcu_read_unlock();
}
static void xen_activate_mm(struct mm_struct *prev, struct mm_struct *next)
--
2.1.4
--
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