[PATCH] KVM: Fix GFP_KERNEL alloc in atomic section bug
KVM does kmalloc() in an atomic section while having preemption disabled via
vcpu_load(). Fix this by moving the ->*_msr setup from the vcpu_setup method
to the vcpu_create method.
(This is also a small speedup for setting up a vcpu, which can in theory be
more frequent than the vcpu_create method).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: 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/vmx.c b/drivers/kvm/vmx.c
index d0a2c2d..fbab07a 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1094,14 +1094,6 @@
rdmsrl(MSR_IA32_SYSENTER_EIP, a);
vmcs_writel(HOST_IA32_SYSENTER_EIP, a); /* 22.2.3 */
- ret = -ENOMEM;
- vcpu->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!vcpu->guest_msrs)
- goto out;
- vcpu->host_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!vcpu->host_msrs)
- goto out_free_guest_msrs;
-
for (i = 0; i < NR_VMX_MSR; ++i) {
u32 index = vmx_msr_index[i];
u32 data_low, data_high;
@@ -1155,8 +1147,6 @@
return 0;
-out_free_guest_msrs:
- kfree(vcpu->guest_msrs);
out:
return ret;
}
@@ -1906,13 +1896,33 @@
{
struct vmcs *vmcs;
+ vcpu->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!vcpu->guest_msrs)
+ return -ENOMEM;
+
+ vcpu->host_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!vcpu->host_msrs)
+ goto out_free_guest_msrs;
+
vmcs = alloc_vmcs();
if (!vmcs)
- return -ENOMEM;
+ goto out_free_msrs;
+
vmcs_clear(vmcs);
vcpu->vmcs = vmcs;
vcpu->launched = 0;
+
return 0;
+
+out_free_msrs:
+ kfree(vcpu->host_msrs);
+ vcpu->host_msrs = NULL;
+
+out_free_guest_msrs:
+ kfree(vcpu->guest_msrs);
+ vcpu->guest_msrs = NULL;
+
+ return -ENOMEM;
}
static struct kvm_arch_ops vmx_arch_ops = {