linux-kernel - [PATCH 3/5] KVM: nVMX: Drop manual clearing of segment cache on nested VMCS switch

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Message-Id: <20200415203454.8296-4-sean.j.christopherson@intel.com>
Date:   Wed, 15 Apr 2020 13:34:52 -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
Subject: [PATCH 3/5] KVM: nVMX: Drop manual clearing of segment cache on nested VMCS switch

Drop the call to vmx_segment_cache_clear() in vmx_switch_vmcs() now that
the entire register cache is reset when switching the active VMCS, e.g.
vmx_segment_cache_test_set() will reset the segment cache due to
VCPU_EXREG_SEGMENTS being unavailable.

Move vmx_segment_cache_clear() to vmx.c now that it's no longer invoked
by the nested code.

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

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 91f04fb4f614..979d66fe0c0e 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -308,7 +308,6 @@ static void vmx_switch_vmcs(struct kvm_vcpu *vcpu, struct loaded_vmcs *vmcs)
 	put_cpu();
 
 	vmx_register_cache_reset(vcpu);
-	vmx_segment_cache_clear(vmx);
 }
 
 /*
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d1c16385904c..9709a6dbeebc 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -437,6 +437,11 @@ static const struct kvm_vmx_segment_field {
 	VMX_SEGMENT_FIELD(LDTR),
 };
 
+static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
+{
+	vmx->segment_cache.bitmask = 0;
+}
+
 static unsigned long host_idt_base;
 
 /*
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 6b668b604898..78c99a60fa49 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -443,11 +443,6 @@ BUILD_CONTROLS_SHADOW(pin, PIN_BASED_VM_EXEC_CONTROL)
 BUILD_CONTROLS_SHADOW(exec, CPU_BASED_VM_EXEC_CONTROL)
 BUILD_CONTROLS_SHADOW(secondary_exec, SECONDARY_VM_EXEC_CONTROL)
 
-static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
-{
-	vmx->segment_cache.bitmask = 0;
-}
-
 static inline void vmx_register_cache_reset(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP)
-- 
2.26.0