From: Lan Tianyu <tianyu....@microsoft.com>

This patch is to check sreg value first and then load vcpu in order
to avoid redundant loading/putting vcpu.

Signed-off-by: Lan Tianyu <tianyu....@microsoft.com>
---
 arch/x86/kvm/x86.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c8a0b54..46da9ec 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7671,6 +7671,10 @@ EXPORT_SYMBOL_GPL(kvm_task_switch);
 
 int kvm_valid_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
 {
+       if (!guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) &&
+                       (sregs->cr4 & X86_CR4_OSXSAVE))
+               return -EINVAL;
+
        if ((sregs->efer & EFER_LME) && (sregs->cr0 & X86_CR0_PG)) {
                /*
                 * When EFER.LME and CR0.PG are set, the processor is in
@@ -7701,14 +7705,10 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
        struct desc_ptr dt;
        int ret = -EINVAL;
 
-       vcpu_load(vcpu);
-
-       if (!guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) &&
-                       (sregs->cr4 & X86_CR4_OSXSAVE))
-               goto out;
-
        if (kvm_valid_sregs(vcpu, sregs))
-               goto out;
+               return ret;
+
+       vcpu_load(vcpu);
 
        apic_base_msr.data = sregs->apic_base;
        apic_base_msr.host_initiated = true;
-- 
2.7.4

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