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KVM: VMX: Drop explicit 'nested' check from vmx_set_cr4()

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Drop vmx_set_cr4()'s explicit check on the 'nested' module param now
that common x86 handles the check by incorporating VMXE into the CR4
reserved bits, via kvm_cpu_caps.  X86_FEATURE_VMX is set in kvm_cpu_caps
(by vmx_set_cpu_caps()), if and only if 'nested' is true.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20201007014417.29276-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2020-10-06 18:44:13 -07:00 committed by Paolo Bonzini
parent d3a9e4146a
commit a447e38a7f
1 changed files with 7 additions and 12 deletions
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19
arch/x86/kvm/vmx/vmx.c
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@ -3123,18 +3123,13 @@ int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
}
}
if (cr4 & X86_CR4_VMXE) {
/*
* To use VMXON (and later other VMX instructions), a guest
* must first be able to turn on cr4.VMXE (see handle_vmon()).
* So basically the check on whether to allow nested VMX
* is here. We operate under the default treatment of SMM,
* so VMX cannot be enabled under SMM. Note, guest CPUID is
* intentionally ignored, it's handled by cr4_guest_rsvd_bits.
*/
if (!nested || is_smm(vcpu))
return 1;
}
/*
* We operate under the default treatment of SMM, so VMX cannot be
* enabled under SMM. Note, whether or not VMXE is allowed at all is
* handled by kvm_valid_cr4().
*/
if ((cr4 & X86_CR4_VMXE) && is_smm(vcpu))
return 1;
if (vmx->nested.vmxon && !nested_cr4_valid(vcpu, cr4))
return 1;