KVM: x86: Mark CR4.UMIP as reserved based on associated CPUID bit
authorSean Christopherson <sean.j.christopherson@intel.com>
Tue, 28 Jan 2020 23:53:44 +0000 (15:53 -0800)
committerPaolo Bonzini <pbonzini@redhat.com>
Wed, 5 Feb 2020 15:30:19 +0000 (16:30 +0100)
commitd76c7fbc01b29257359ed8b0d16d662e725b7bf9
tree0e5b87c01db981ba243a04b7ae578a3e041bebff
parentbcfcff640c4d736933c5990d5a801d6a0c22c28b
KVM: x86: Mark CR4.UMIP as reserved based on associated CPUID bit

Re-add code to mark CR4.UMIP as reserved if UMIP is not supported by the
host.  The UMIP handling was unintentionally dropped during a recent
refactoring.

Not flagging CR4.UMIP allows the guest to set its CR4.UMIP regardless of
host support or userspace desires.  On CPUs with UMIP support, including
emulated UMIP, this allows the guest to enable UMIP against the wishes
of the userspace VMM.  On CPUs without any form of UMIP, this results in
a failed VM-Enter due to invalid guest state.

Fixes: 345599f9a2928 ("KVM: x86: Add macro to ensure reserved cr4 bits checks stay in sync")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/x86.c