Changing it afterwards doesn't make too much sense and will only result
in inconsistencies.
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
Documentation/virtual/kvm/api.txt | 1 +
arch/x86/kvm/x86.c | 8 +++++++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 22bc5a0..dd2dd96 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -1131,6 +1131,7 @@ This ioctl is required on Intel-based hosts. This is needed on Intel hardware
because of a quirk in the virtualization implementation (see the internals
documentation when it pops into existence).
+Fails if any VCPU has already been created.
4.41 KVM_SET_BOOT_CPU_ID
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c5dfea9..86242ee 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4001,10 +4001,16 @@ long kvm_arch_vm_ioctl(struct file *filp,
case KVM_SET_IDENTITY_MAP_ADDR: {
u64 ident_addr;
+ mutex_lock(&kvm->lock);
+ r = -EINVAL;
+ if (kvm->created_vcpus)
+ goto set_identity_unlock;
r = -EFAULT;
if (copy_from_user(&ident_addr, argp, sizeof ident_addr))
- goto out;
+ goto set_identity_unlock;
r = kvm_vm_ioctl_set_identity_map_addr(kvm, ident_addr);
+set_identity_unlock:
+ mutex_unlock(&kvm->lock);
break;
}
case KVM_SET_NR_MMU_PAGES:
--
2.9.4
