x86/KVM/VMX: Extend add_atomic_switch_msr() to allow VMENTER only MSRs

x86/KVM/VMX: Extend add_atomic_switch_msr() to allow VMENTER only MSRs

commit 989e3992d2eca32c3f1404f2bc91acda3aa122d8 upstream

The IA32_FLUSH_CMD MSR needs only to be written on VMENTER. Extend
add_atomic_switch_msr() with an entry_only parameter to allow storing the
MSR only in the guest (ENTRY) MSR array.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>