[PATCH 5.5 158/176] KVM: x86: Remove spurious kvm_mmu_unload() from vcpu destruction path

Greg Kroah-Hartman
2020-03-03T17:51:11Z

From: Sean Christopherson <sean.j.christopherson@intel.com>

commit 9d979c7e6ff43ca3200ffcb74f57415fd633a2da upstream.

x86 does not load its MMU until KVM_RUN, which cannot be invoked until
after vCPU creation succeeds. Given that kvm_arch_vcpu_destroy() is
called if and only if vCPU creation fails, it is impossible for the MMU
to be loaded.

Note, the bogus kvm_mmu_unload() call was added during an unrelated
refactoring of vCPU allocation, i.e. was presumably added as an
opportunstic "fix" for a perceived leak.

Fixes: fb3f0f51d92d1 ("KVM: Dynamically allocate vcpus")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/kvm/x86.c | 4 ----
1 file changed, 4 deletions(-)

--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9229,10 +9229,6 @@ void kvm_arch_vcpu_destroy(struct kvm_vc
{
vcpu->arch.apf.msr_val = 0;

- vcpu_load(vcpu);
- kvm_mmu_unload(vcpu);
- vcpu_put(vcpu);
-
kvm_arch_vcpu_free(vcpu);
}