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[PATCH 6/7] KVM/x86: update the comment of memory barrier in the vcpu_enter_guest()

From Lan Tianyu <tianyu.lan@intel.com>
Newsgroups linux.kernel
Subject [PATCH 6/7] KVM/x86: update the comment of memory barrier in the vcpu_enter_guest()
Date 2016-03-13 04:30 +0100
Message-ID <rc4T8-830-13@gated-at.bofh.it> (permalink)
References <rc4T7-830-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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The barrier also orders the write to mode from any reads
to the page tables done and so update the comment.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
 arch/x86/kvm/x86.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bcbce0f..4bdb4e6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6589,8 +6589,12 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
 
 	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
 
-	/* We should set ->mode before check ->requests,
-	 * see the comment in make_all_cpus_request.
+	/*
+	 * We should set ->mode before check ->requests,
+	 * Please see the comment in kvm_make_all_cpus_request.
+	 * This also orders the write to mode from any reads
+	 * to the page tables done while the VCPU is running.
+	 * Please see the comment in kvm_flush_remote_tlbs.
 	 */
 	smp_mb__after_srcu_read_unlock();
 
-- 
1.8.4.rc0.1.g8f6a3e5.dirty

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Thread

[PATCH 0/7] KVM/X86/PPC: Clear up kvm mmu memory barriers and update related comments Lan Tianyu <tianyu.lan@intel.com> - 2016-03-13 04:30 +0100
  [PATCH 4/7] KVM/x86: Call smp_wmb() before increasing tlbs_dirty Lan Tianyu <tianyu.lan@intel.com> - 2016-03-13 04:30 +0100
  [PATCH 7/7] KVM/PPC:  update the comment of memory barrier in the kvmppc_prepare_to_enter() Lan Tianyu <tianyu.lan@intel.com> - 2016-03-13 04:30 +0100
  [PATCH 5/7] KVM: Replace smp_mb() with smp_load_acquire() in the kvm_flush_remote_tlbs() Lan Tianyu <tianyu.lan@intel.com> - 2016-03-13 04:30 +0100
  [PATCH 6/7] KVM/x86: update the comment of memory barrier in the vcpu_enter_guest() Lan Tianyu <tianyu.lan@intel.com> - 2016-03-13 04:30 +0100
  Re: [PATCH 0/7] KVM/X86/PPC: Clear up kvm mmu memory barriers and  update related comments Paolo Bonzini <pbonzini@redhat.com> - 2016-03-14 14:10 +0100

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