linux-kernel - [PATCH 61/61] KVM: x86: Move VMX's host

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Date:   Sat,  1 Feb 2020 10:52:18 -0800
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 61/61] KVM: x86: Move VMX's host_efer to common x86 code

Move host_efer to common x86 code and use it for CPUID's is_efer_nx() to
avoid constantly re-reading the MSR.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/include/asm/kvm_host.h | 2 ++
 arch/x86/kvm/cpuid.c            | 5 +----
 arch/x86/kvm/vmx/vmx.c          | 3 ---
 arch/x86/kvm/vmx/vmx.h          | 1 -
 arch/x86/kvm/x86.c              | 5 +++++
 5 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4165d3ef11e4..a2a091d328c6 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1257,6 +1257,8 @@ struct kvm_arch_async_pf {
 	bool direct_map;
 };
 
+extern u64 __read_mostly host_efer;
+
 extern struct kvm_x86_ops *kvm_x86_ops;
 extern struct kmem_cache *x86_fpu_cache;
 
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 3d287fc6eb6e..e8beb1e542a8 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -134,10 +134,7 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
 
 static int is_efer_nx(void)
 {
-	unsigned long long efer = 0;
-
-	rdmsrl_safe(MSR_EFER, &efer);
-	return efer & EFER_NX;
+	return host_efer & EFER_NX;
 }
 
 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e349689ac0cf..0009066e2009 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -433,7 +433,6 @@ static const struct kvm_vmx_segment_field {
 	VMX_SEGMENT_FIELD(LDTR),
 };
 
-u64 host_efer;
 static unsigned long host_idt_base;
 
 /*
@@ -7577,8 +7576,6 @@ static __init int hardware_setup(void)
 	struct desc_ptr dt;
 	int r, i, ept_lpage_level;
 
-	rdmsrl_safe(MSR_EFER, &host_efer);
-
 	store_idt(&dt);
 	host_idt_base = dt.address;
 
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 70eafa88876a..0e50fbcb8413 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -12,7 +12,6 @@
 #include "vmcs.h"
 
 extern const u32 vmx_msr_index[];
-extern u64 host_efer;
 
 extern u32 get_umwait_control_msr(void);
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b40488fd2969..2103101eca78 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -185,6 +185,9 @@ static struct kvm_shared_msrs __percpu *shared_msrs;
 				| XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \
 				| XFEATURE_MASK_PKRU)
 
+u64 __read_mostly host_efer;
+EXPORT_SYMBOL_GPL(host_efer);
+
 static u64 __read_mostly host_xss;
 
 struct kvm_stats_debugfs_item debugfs_entries[] = {
@@ -9590,6 +9593,8 @@ int kvm_arch_hardware_setup(void)
 {
 	int r;
 
+	rdmsrl_safe(MSR_EFER, &host_efer);
+
 	kvm_set_cpu_caps();
 
 	r = kvm_x86_ops->hardware_setup();
-- 
2.24.1