KVM: x86: Let the guest own CR4.FSGSBASE
authorLai Jiangshan <laijs@linux.alibaba.com>
Wed, 30 Sep 2020 04:16:59 +0000 (21:16 -0700)
committerPaolo Bonzini <pbonzini@redhat.com>
Wed, 21 Oct 2020 21:48:50 +0000 (17:48 -0400)
commit30031c2b0574f43cc6888532b715f639afd39196
tree7673ad60190beb86ca26f993b9381df6ccddf5a6
parent2ed41aa631fc0251cedea3ae98802cb72079d198
KVM: x86: Let the guest own CR4.FSGSBASE

Add FSGSBASE to the set of possible guest-owned CR4 bits, i.e. let the
guest own it on VMX.  KVM never queries the guest's CR4.FSGSBASE value,
thus there is no reason to force VM-Exit on FSGSBASE being toggled.

Note, because FSGSBASE is conditionally available, this is dependent on
recent changes to intercept reserved CR4 bits and to update the CR4
guest/host mask in response to guest CPUID changes.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
[sean: added justification in changelog]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200930041659.28181-6-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
arch/x86/kvm/kvm_cache_regs.h