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

From: Sean Christopherson
Date: Wed Apr 15 2020 - 16:35:56 EST


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@xxxxxxxxx>
---
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