KVM: MMU: Switch to mmu spinlock

Convert the synchronization of the shadow handling to a separate mmu_lock
spinlock.

Also guard fetch() by mmap_sem in read-mode to protect against alias
and memslot changes.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 0 insertions, 2 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c39493feba46..3d251f894a8d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1477,7 +1477,6 @@ static int alloc_apic_access_page(struct kvm *kvm)
         struct kvm_userspace_memory_region kvm_userspace_mem;
         int r = 0;
 
-        mutex_lock(&kvm->lock);
         down_write(&current->mm->mmap_sem);
         if (kvm->arch.apic_access_page)
                 goto out;
@@ -1491,7 +1490,6 @@ static int alloc_apic_access_page(struct kvm *kvm)
         kvm->arch.apic_access_page = gfn_to_page(kvm, 0xfee00);
 out:
         up_write(&current->mm->mmap_sem);
-        mutex_unlock(&kvm->lock);
         return r;
 }