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From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Sean Christopherson <sean.j.christopherson@intel.com>
Subject: [PATCH v4 08/11] KVM: VMX: Explicitly check for hv_remote_flush_tlb when loading pgd
Date: Fri,  5 Mar 2021 10:31:20 -0800	[thread overview]
Message-ID: <20210305183123.3978098-9-seanjc@google.com> (raw)
In-Reply-To: <20210305183123.3978098-1-seanjc@google.com>

From: Sean Christopherson <sean.j.christopherson@intel.com>

Explicitly check that kvm_x86_ops.tlb_remote_flush() points at Hyper-V's
implementation for PV flushing instead of assuming that a non-NULL
implementation means running on Hyper-V.  Wrap the related logic in
ifdeffery as hv_remote_flush_tlb() is defined iff CONFIG_HYPERV!=n.

Short term, the explicit check makes it more obvious why a non-NULL
tlb_remote_flush() triggers EPTP shenanigans.  Long term, this will
allow TDX to define its own implementation of tlb_remote_flush() without
running afoul of Hyper-V.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/vmx/vmx.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cd0d787b0a85..aca6849c409a 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -576,6 +576,21 @@ static int hv_enable_direct_tlbflush(struct kvm_vcpu *vcpu)
 
 #endif /* IS_ENABLED(CONFIG_HYPERV) */
 
+static void hv_load_mmu_eptp(struct kvm_vcpu *vcpu, u64 eptp)
+{
+#if IS_ENABLED(CONFIG_HYPERV)
+	struct kvm_vmx *kvm_vmx = to_kvm_vmx(vcpu->kvm);
+
+	if (kvm_x86_ops.tlb_remote_flush == hv_remote_flush_tlb) {
+		spin_lock(&kvm_vmx->ept_pointer_lock);
+		to_vmx(vcpu)->ept_pointer = eptp;
+		if (eptp != kvm_vmx->hv_tlb_eptp)
+			kvm_vmx->hv_tlb_eptp = INVALID_PAGE;
+		spin_unlock(&kvm_vmx->ept_pointer_lock);
+	}
+#endif
+}
+
 /*
  * Comment's format: document - errata name - stepping - processor name.
  * Refer from
@@ -3114,13 +3129,7 @@ static void vmx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
 		eptp = construct_eptp(vcpu, root_hpa, root_level);
 		vmcs_write64(EPT_POINTER, eptp);
 
-		if (kvm_x86_ops.tlb_remote_flush) {
-			spin_lock(&to_kvm_vmx(kvm)->ept_pointer_lock);
-			to_vmx(vcpu)->ept_pointer = eptp;
-			if (eptp != to_kvm_vmx(kvm)->hv_tlb_eptp)
-				to_kvm_vmx(kvm)->hv_tlb_eptp = INVALID_PAGE;
-			spin_unlock(&to_kvm_vmx(kvm)->ept_pointer_lock);
-		}
+		hv_load_mmu_eptp(vcpu, eptp);
 
 		if (!enable_unrestricted_guest && !is_paging(vcpu))
 			guest_cr3 = to_kvm_vmx(kvm)->ept_identity_map_addr;
-- 
2.30.1.766.gb4fecdf3b7-goog


  parent reply	other threads:[~2021-03-05 18:35 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-05 18:31 [PATCH v4 00/11] KVM: VMX: Clean up Hyper-V PV TLB flush Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 01/11] KVM: x86: Get active PCID only when writing a CR3 value Sean Christopherson
2021-03-08 10:05   ` Vitaly Kuznetsov
2021-03-05 18:31 ` [PATCH v4 02/11] KVM: VMX: Track common EPTP for Hyper-V's paravirt TLB flush Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 03/11] KVM: VMX: Stash kvm_vmx in a local variable for Hyper-V " Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 04/11] KVM: VMX: Fold Hyper-V EPTP checking into it's only caller Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 05/11] KVM: VMX: Do Hyper-V TLB flush iff vCPU's EPTP hasn't been flushed Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 06/11] KVM: VMX: Invalidate hv_tlb_eptp to denote an EPTP mismatch Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 07/11] KVM: VMX: Don't invalidate hv_tlb_eptp if the new EPTP matches Sean Christopherson
2021-03-05 18:31 ` Sean Christopherson [this message]
2021-03-05 18:31 ` [PATCH v4 09/11] KVM: VMX: Define Hyper-V paravirt TLB flush fields iff Hyper-V is enabled Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 10/11] KVM: VMX: Skip additional Hyper-V TLB EPTP flushes if one fails Sean Christopherson
2021-03-05 18:31 ` [PATCH v4 11/11] KVM: VMX: Track root HPA instead of EPTP for paravirt Hyper-V TLB flush Sean Christopherson
2021-03-05 18:33 ` [PATCH v4 00/11] KVM: VMX: Clean up Hyper-V PV " Sean Christopherson
2021-03-08 11:50 ` Paolo Bonzini
2021-03-09  1:18   ` Sean Christopherson
2021-03-09  8:35     ` Paolo Bonzini

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