KVM: nVMX: preserve SECONDARY_EXEC_DESC without UMIP

L1 might want to use SECONDARY_EXEC_DESC, so we must not clear the VMCS
bit if UMIP is not being emulated.

We must still set the bit when emulating UMIP as the feature can be
passed to L2 where L0 will do the emulation and because L2 can change
CR4 without a VM exit, we should clear the bit if UMIP is disabled.

Fixes: 0367f205a3 ("KVM: vmx: add support for emulating UMIP")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This commit is contained in:
Radim Krčmář 2018-01-31 18:12:50 +01:00 committed by Paolo Bonzini
parent 0b2e9904c1
commit 9915824620

View File

@ -4485,7 +4485,8 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
SECONDARY_EXEC_DESC);
hw_cr4 &= ~X86_CR4_UMIP;
} else
} else if (!is_guest_mode(vcpu) ||
!nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC))
vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,
SECONDARY_EXEC_DESC);