mirror of https://gitee.com/openkylin/linux.git
KVM: VMX: Give the guest ownership of cr0.ts when the fpu is active
If the guest fpu is loaded, there is nothing interesing about cr0.ts; let the guest play with it as it will. This makes context switches between fpu intensive guest processes faster, as we won't trap the clts and cr0 write instructions. [marcelo: fix cr0 read shadow update on fpu deactivation; kills F8 install] Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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@ -803,12 +803,20 @@ static void vmx_fpu_activate(struct kvm_vcpu *vcpu)
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if (kvm_read_cr0_bits(vcpu, X86_CR0_TS))
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if (kvm_read_cr0_bits(vcpu, X86_CR0_TS))
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vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
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vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
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update_exception_bitmap(vcpu);
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update_exception_bitmap(vcpu);
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vcpu->arch.cr0_guest_owned_bits = X86_CR0_TS;
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vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);
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}
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}
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static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu);
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static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
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static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu)
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{
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{
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vmx_decache_cr0_guest_bits(vcpu);
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vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
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vmcs_set_bits(GUEST_CR0, X86_CR0_TS);
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update_exception_bitmap(vcpu);
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update_exception_bitmap(vcpu);
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vcpu->arch.cr0_guest_owned_bits = 0;
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vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits);
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vmcs_writel(CR0_READ_SHADOW, vcpu->arch.cr0);
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}
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}
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static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
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static unsigned long vmx_get_rflags(struct kvm_vcpu *vcpu)
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@ -2996,8 +3004,7 @@ static int handle_cr(struct kvm_vcpu *vcpu)
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};
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};
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break;
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break;
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case 2: /* clts */
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case 2: /* clts */
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vcpu->arch.cr0 &= ~X86_CR0_TS;
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vmx_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~X86_CR0_TS));
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vmcs_writel(CR0_READ_SHADOW, kvm_read_cr0(vcpu));
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trace_kvm_cr_write(0, kvm_read_cr0(vcpu));
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trace_kvm_cr_write(0, kvm_read_cr0(vcpu));
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skip_emulated_instruction(vcpu);
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skip_emulated_instruction(vcpu);
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return 1;
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return 1;
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