[PATCH] kvm: fix GFP_KERNEL allocation in atomic section in kvm_dev_ioctl_create_vcpu()
fix an GFP_KERNEL allocation in atomic section: kvm_dev_ioctl_create_vcpu()
called kvm_mmu_init(), which calls alloc_pages(), while holding the vcpu.
The fix is to set up the MMU state in two phases: kvm_mmu_create() and
kvm_mmu_setup().
(NOTE: free_vcpus does an kvm_mmu_destroy() call so there's no need for any
extra teardown branch on allocation/init failure here.)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 2670219..100df6f 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -319,7 +319,8 @@
void kvm_exit_arch(void);
void kvm_mmu_destroy(struct kvm_vcpu *vcpu);
-int kvm_mmu_init(struct kvm_vcpu *vcpu);
+int kvm_mmu_create(struct kvm_vcpu *vcpu);
+int kvm_mmu_setup(struct kvm_vcpu *vcpu);
int kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 9735445..ce7fe64 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -522,12 +522,14 @@
if (r < 0)
goto out_free_vcpus;
+ r = kvm_mmu_create(vcpu);
+ if (r < 0)
+ goto out_free_vcpus;
+
kvm_arch_ops->vcpu_load(vcpu);
-
- r = kvm_arch_ops->vcpu_setup(vcpu);
+ r = kvm_mmu_setup(vcpu);
if (r >= 0)
- r = kvm_mmu_init(vcpu);
-
+ r = kvm_arch_ops->vcpu_setup(vcpu);
vcpu_put(vcpu);
if (r < 0)
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 85887fc..790423c 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -639,28 +639,22 @@
return -ENOMEM;
}
-int kvm_mmu_init(struct kvm_vcpu *vcpu)
+int kvm_mmu_create(struct kvm_vcpu *vcpu)
{
- int r;
-
ASSERT(vcpu);
ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
ASSERT(list_empty(&vcpu->free_pages));
- r = alloc_mmu_pages(vcpu);
- if (r)
- goto out;
+ return alloc_mmu_pages(vcpu);
+}
- r = init_kvm_mmu(vcpu);
- if (r)
- goto out_free_pages;
+int kvm_mmu_setup(struct kvm_vcpu *vcpu)
+{
+ ASSERT(vcpu);
+ ASSERT(!VALID_PAGE(vcpu->mmu.root_hpa));
+ ASSERT(!list_empty(&vcpu->free_pages));
- return 0;
-
-out_free_pages:
- free_mmu_pages(vcpu);
-out:
- return r;
+ return init_kvm_mmu(vcpu);
}
void kvm_mmu_destroy(struct kvm_vcpu *vcpu)