[24/43] KVM: nVMX: Don't speculatively write APIC-access page address
diff mbox series

Message ID 1560445409-17363-25-git-send-email-pbonzini@redhat.com
State New
Headers show
Series
  • VMX optimizations
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Commit Message

Paolo Bonzini June 13, 2019, 5:03 p.m. UTC
From: Sean Christopherson <sean.j.christopherson@intel.com>

If nested_get_vmcs12_pages() fails to map L1's APIC_ACCESS_ADDR into
L2, then it disables SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES in vmcs02.
In other words, the APIC_ACCESS_ADDR in vmcs02 is guaranteed to be
written with the correct value before being consumed by hardware, drop
the unneessary VMWRITE.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/nested.c | 8 --------
 1 file changed, 8 deletions(-)

Patch
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diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index d055bbc5cbde..a012118e6c8c 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2083,14 +2083,6 @@  static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12)
 			vmcs_write16(GUEST_INTR_STATUS,
 				vmcs12->guest_intr_status);
 
-		/*
-		 * Write an illegal value to APIC_ACCESS_ADDR. Later,
-		 * nested_get_vmcs12_pages will either fix it up or
-		 * remove the VM execution control.
-		 */
-		if (exec_control & SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)
-			vmcs_write64(APIC_ACCESS_ADDR, -1ull);
-
 		vmcs_write32(SECONDARY_VM_EXEC_CONTROL, exec_control);
 	}