[PATCH 28/43] KVM: nVMX: Don't update GUEST_BNDCFGS if it's clean in HV eVMCS

From: Paolo Bonzini
Date: Thu Jun 13 2019 - 13:10:57 EST


From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

L1 is responsible for dirtying GUEST_GRP1 if it writes GUEST_BNDCFGS.

Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 138f27597c91..d5bfe0cbc4fb 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2197,6 +2197,10 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
vmcs_write64(GUEST_PDPTR2, vmcs12->guest_pdptr2);
vmcs_write64(GUEST_PDPTR3, vmcs12->guest_pdptr3);
}
+
+ if (kvm_mpx_supported() && vmx->nested.nested_run_pending &&
+ (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
+ vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs);
}

if (nested_cpu_has_xsaves(vmcs12))
@@ -2232,10 +2236,6 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);

set_cr4_guest_host_mask(vmx);
-
- if (kvm_mpx_supported() && vmx->nested.nested_run_pending &&
- (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_BNDCFGS))
- vmcs_write64(GUEST_BNDCFGS, vmcs12->guest_bndcfgs);
}

/*
--
1.8.3.1