[PATCH 03/15] KVM: nVMX: Always sync GUEST_BNDCFGS when it comes from vmcs01

Sean Christopherson
2019-05-07T16:07:14Z

If L1 does not set VM_ENTRY_LOAD_BNDCFGS, then L1's BNDCFGS value must
be propagated to vmcs02 since KVM always runs with VM_ENTRY_LOAD_BNDCFGS
when MPX is supported. Because the value effectively comes from vmcs01,
vmcs02 must be updated even if vmcs12 is clean.

Fixes: 62cf9bd8118c4 ("KVM: nVMX: Fix emulation of VM_ENTRY_LOAD_BNDCFGS")
Cc: stable@vger.kernel.org
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/vmx/nested.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 63f2ca847f05..9c31e82fb7c5 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2231,13 +2231,9 @@ static void prepare_vmcs02_full(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)

set_cr4_guest_host_mask(vmx);

- if (kvm_mpx_supported()) {
- if (vmx->nested.nested_run_pending &&
- (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
- vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs);
- else
- vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs);
- }
+ if (kvm_mpx_supported() && vmx->nested.nested_run_pending &&
+ (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
+ vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs);
}

/*
@@ -2280,6 +2276,9 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
kvm_set_dr(vcpu, 7, vcpu->arch.dr7);
vmcs_write64(GUEST_IA32_DEBUGCTL, vmx->nested.vmcs01_debugctl);
}
+ if (kvm_mpx_supported() && (!vmx->nested.nested_run_pending ||
+ !(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS)))
+ vmcs_write64(GUEST_BNDCFGS, vmx->nested.vmcs01_guest_bndcfgs);
vmx_set_rflags(vcpu, vmcs12->guest_rflags);

/* EXCEPTION_BITMAP and CR0_GUEST_HOST_MASK should basically be the
--
2.21.0