4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Roman Kagan rkagan@virtuozzo.com
commit 63aff65573d73eb8dda4732ad4ef222dd35e4862 upstream.
VPID for the nested vcpu is allocated at vmx_create_vcpu whenever nested vmx is turned on with the module parameter.
However, it's only freed if the L1 guest has executed VMXON which is not a given.
As a result, on a system with nested==on every creation+deletion of an L1 vcpu without running an L2 guest results in leaking one vpid. Since the total number of vpids is limited to 64k, they can eventually get exhausted, preventing L2 from starting.
Delay allocation of the L2 vpid until VMXON emulation, thus matching its freeing.
Fixes: 5c614b3583e7b6dab0c86356fa36c2bcbb8322a0 Cc: stable@vger.kernel.org Signed-off-by: Roman Kagan rkagan@virtuozzo.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kvm/vmx.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
--- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6843,6 +6843,8 @@ static int handle_vmon(struct kvm_vcpu * HRTIMER_MODE_REL); vmx->nested.preemption_timer.function = vmx_preemption_timer_fn;
+ vmx->nested.vpid02 = allocate_vpid(); + vmx->nested.vmxon = true;
skip_emulated_instruction(vcpu); @@ -8887,10 +8889,8 @@ static struct kvm_vcpu *vmx_create_vcpu( goto free_vmcs; }
- if (nested) { + if (nested) nested_vmx_setup_ctls_msrs(vmx); - vmx->nested.vpid02 = allocate_vpid(); - }
vmx->nested.posted_intr_nv = -1; vmx->nested.current_vmptr = -1ull; @@ -8899,7 +8899,6 @@ static struct kvm_vcpu *vmx_create_vcpu( return &vmx->vcpu;
free_vmcs: - free_vpid(vmx->nested.vpid02); free_loaded_vmcs(vmx->loaded_vmcs); free_msrs: kfree(vmx->guest_msrs);