linux-kernel - [PATCH v3 12/37] KVM: VMX: Drop redundant capability checks in low level INVVPID helpers

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Date:   Fri, 20 Mar 2020 14:28:08 -0700
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Ben Gardon <bgardon@...gle.com>,
        Junaid Shahid <junaids@...gle.com>,
        Liran Alon <liran.alon@...cle.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        John Haxby <john.haxby@...cle.com>,
        Miaohe Lin <linmiaohe@...wei.com>,
        Tom Lendacky <thomas.lendacky@....com>
Subject: [PATCH v3 12/37] KVM: VMX: Drop redundant capability checks in low level INVVPID helpers

Remove the INVVPID capabilities checks from vpid_sync_vcpu_single() and
vpid_sync_vcpu_global() now that all callers ensure the INVVPID variant
is supported.  Note, in some cases the guarantee is provided in concert
with hardware_setup(), which enables VPID if and only if at least of
invvpid_single() or invvpid_global() is supported.

Drop the WARN_ON_ONCE() from vmx_flush_tlb() as vpid_sync_vcpu_single()
will trigger a WARN() on INVVPID failure, i.e. if SINGLE_CONTEXT isn't
supported.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/kvm/vmx/ops.h | 6 ++----
 arch/x86/kvm/vmx/vmx.h | 1 -
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/vmx/ops.h b/arch/x86/kvm/vmx/ops.h
index 39122699cfeb..aa1aab52971a 100644
--- a/arch/x86/kvm/vmx/ops.h
+++ b/arch/x86/kvm/vmx/ops.h
@@ -258,14 +258,12 @@ static inline void vpid_sync_vcpu_single(int vpid)
 	if (vpid == 0)
 		return;
 
-	if (cpu_has_vmx_invvpid_single())
-		__invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vpid, 0);
+	__invvpid(VMX_VPID_EXTENT_SINGLE_CONTEXT, vpid, 0);
 }
 
 static inline void vpid_sync_vcpu_global(void)
 {
-	if (cpu_has_vmx_invvpid_global())
-		__invvpid(VMX_VPID_EXTENT_ALL_CONTEXT, 0, 0);
+	__invvpid(VMX_VPID_EXTENT_ALL_CONTEXT, 0, 0);
 }
 
 static inline void vpid_sync_context(int vpid)
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index d6d67b816ebe..3770ae111e6a 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -537,7 +537,6 @@ static inline void vmx_flush_tlb(struct kvm_vcpu *vcpu, bool invalidate_gpa)
 			if (cpu_has_vmx_invvpid_global()) {
 				vpid_sync_vcpu_global();
 			} else {
-				WARN_ON_ONCE(!cpu_has_vmx_invvpid_single());
 				vpid_sync_vcpu_single(vmx->vpid);
 				vpid_sync_vcpu_single(vmx->nested.vpid02);
 			}
-- 
2.24.1