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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org, Nadav Amit <nadav.amit@gmail.com>,
	Liran Alon <liran.alon@oracle.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: [PATCH 09/15] KVM: nVMX: Don't speculatively write APIC-access page address
Date: Tue,  7 May 2019 09:06:34 -0700	[thread overview]
Message-ID: <20190507160640.4812-10-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20190507160640.4812-1-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>
---
 arch/x86/kvm/vmx/nested.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 32d233dee067..29892c560771 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -2082,14 +2082,6 @@ 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);
 	}
 
-- 
2.21.0


  parent reply	other threads:[~2019-05-07 16:07 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-07 16:06 [PATCH 00/15] KVM: nVMX: Optimize nested VM-Entry Sean Christopherson
2019-05-07 16:06 ` [PATCH 01/15] KVM: nVMX: Don't dump VMCS if virtual APIC page can't be mapped Sean Christopherson
2019-05-07 20:09   ` Paolo Bonzini
2019-05-07 16:06 ` [PATCH 02/15] KVM: VMX: Always signal #GP on WRMSR to MSR_IA32_CR_PAT with bad value Sean Christopherson
2019-05-07 16:06 ` [PATCH 03/15] KVM: nVMX: Always sync GUEST_BNDCFGS when it comes from vmcs01 Sean Christopherson
2019-05-07 16:06 ` [PATCH 04/15] KVM: nVMX: Write ENCLS-exiting bitmap once per vmcs02 Sean Christopherson
2019-05-07 16:06 ` [PATCH 05/15] KVM: nVMX: Don't rewrite GUEST_PML_INDEX during nested VM-Entry Sean Christopherson
2019-06-06 15:49   ` Paolo Bonzini
2019-05-07 16:06 ` [PATCH 06/15] KVM: nVMX: Don't "put" vCPU or host state when switching VMCS Sean Christopherson
2019-06-06 16:24   ` Paolo Bonzini
2019-06-06 18:57     ` Sean Christopherson
2019-06-07 17:00       ` Paolo Bonzini
2019-06-07 17:08         ` Sean Christopherson
2019-05-07 16:06 ` [PATCH 07/15] KVM: nVMX: Don't reread VMCS-agnostic " Sean Christopherson
2019-05-07 21:01   ` Paolo Bonzini
2019-05-07 16:06 ` [PATCH 08/15] KVM: nVMX: Don't speculatively write virtual-APIC page address Sean Christopherson
2019-05-07 16:06 ` Sean Christopherson [this message]
2019-05-07 16:06 ` [PATCH 10/15] KVM: nVMX: Update vmcs12 for MSR_IA32_CR_PAT when it's written Sean Christopherson
2019-05-07 16:06 ` [PATCH 11/15] KVM: nVMX: Update vmcs12 for SYSENTER MSRs when they're written Sean Christopherson
2019-06-06 16:35   ` Paolo Bonzini
2019-05-07 16:06 ` [PATCH 12/15] KVM: nVMX: Update vmcs12 for MSR_IA32_DEBUGCTLMSR when it's written Sean Christopherson
2019-05-07 16:06 ` [PATCH 13/15] KVM: nVMX: Update vmcs02 GUEST_IA32_DEBUGCTL only when vmcs12 is dirty Sean Christopherson
2019-06-06 16:39   ` Paolo Bonzini
2019-05-07 16:06 ` [PATCH 14/15] KVM: nVMX: Don't update GUEST_BNDCFGS if it's clean in HV eVMCS Sean Christopherson
2019-05-07 16:06 ` [PATCH 15/15] KVM: nVMX: Copy PDPTRs to/from vmcs12 only when necessary Sean Christopherson
2019-06-06 16:53   ` Paolo Bonzini
2019-06-06 16:54 ` [PATCH 00/15] KVM: nVMX: Optimize nested VM-Entry Paolo Bonzini

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