[PATCH v2 63/66] KVM: x86: Move VMX's host_efer to common x86 code

Sean Christopherson
2020-03-03T00:00:11Z

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.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.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 e0f5607c66b5..27983e5895d9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1263,6 +1263,8 @@ 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 f879fcbd6fb2..f0c4ad04d4dc 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 1fbe54dc3263..180aeebd029a 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;

/*
@@ -7642,8 +7641,6 @@ 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 9a51a3a77233..fc45bdb5a62f 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 cc9b543d210b..aa2a085f115c 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[] = {
@@ -9559,6 +9562,8 @@ 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