[PATCH] KVM: MMU: oom handling

When beginning to process a page fault, make sure we have enough shadow pages
available to service the fault.  If not, free some pages.

Signed-off-by: Avi Kivity <avi@qumranet.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 13 deletions

diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index cf4b74cc75b5..03c474aaedde 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -246,8 +246,6 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
                 }
                 shadow_page = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
                                                metaphysical, shadow_ent);
-                if (!shadow_page)
-                        return ERR_PTR(-ENOMEM);
                 shadow_addr = shadow_page->page_hpa;
                 shadow_pte = shadow_addr | PT_PRESENT_MASK | PT_ACCESSED_MASK
                         | PT_WRITABLE_MASK | PT_USER_MASK;
@@ -347,17 +345,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
         /*
          * Look up the shadow pte for the faulting address.
          */
-        for (;;) {
-                FNAME(walk_addr)(&walker, vcpu, addr);
-                shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
-                if (IS_ERR(shadow_pte)) {  /* must be -ENOMEM */
-                        printk("%s: oom\n", __FUNCTION__);
-                        nonpaging_flush(vcpu);
-                        FNAME(release_walker)(&walker);
-                        continue;
-                }
-                break;
-        }
+        FNAME(walk_addr)(&walker, vcpu, addr);
+        shadow_pte = FNAME(fetch)(vcpu, addr, &walker);
 
         /*
          * The page is not mapped by the guest.  Let the guest handle it.