From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liran Alon Subject: Re: [PATCH v1 3/8] kvm:vmx Enable loading CET state bit while guest CR4.CET is being set. Date: Wed, 26 Dec 2018 10:52:38 +0200 Message-ID: <9307C088-C8F8-4587-ABB4-3CADF2CC3117@oracle.com> References: <20181226081532.30698-1-weijiang.yang@intel.com> <20181226081532.30698-4-weijiang.yang@intel.com> Mime-Version: 1.0 (Mac OS X Mail 11.1 \(3445.4.7\)) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: Paolo Bonzini , rkrcmar@redhat.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, mst@redhat.com, yu-cheng.yu@intel.com, yi.z.zhang@intel.com, hjl.tools@gmail.com, Zhang Yi Z To: Yang Weijiang Return-path: In-Reply-To: <20181226081532.30698-4-weijiang.yang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org > On 26 Dec 2018, at 10:15, Yang Weijiang = wrote: >=20 > This bit controls whether guest CET states will be loaded on guest = entry. >=20 > Signed-off-by: Zhang Yi Z > Signed-off-by: Yang Weijiang > --- > arch/x86/kvm/vmx.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) >=20 > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 7bbb8b26e901..25fa6bd2fb95 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -1045,6 +1045,8 @@ struct vcpu_vmx { >=20 > bool req_immediate_exit; >=20 > + bool vcpu_cet_on; > + > /* Support for PML */ > #define PML_ENTITY_NUM 512 > struct page *pml_pg; > @@ -5409,6 +5411,23 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu, = unsigned long cr4) > return 1; > } >=20 > + /* > + * When CET.CR4 is being set, it means we're enabling CET for You probably meant to write here CR4.CET. > + * the guest, then enable loading CET state bit in entry = control. > + * Otherwise, clear loading CET bit to disable guest CET. > + */ > + if (cr4 & X86_CR4_CET) { > + if (!to_vmx(vcpu)->vcpu_cet_on) { > + vmcs_set_bits(VM_ENTRY_CONTROLS, > + VM_ENTRY_LOAD_GUEST_CET_STATE); > + to_vmx(vcpu)->vcpu_cet_on =3D 1; > + } > + } else if (to_vmx(vcpu)->vcpu_cet_on) { > + vmcs_clear_bits(VM_ENTRY_CONTROLS, > + VM_ENTRY_LOAD_GUEST_CET_STATE); > + to_vmx(vcpu)->vcpu_cet_on =3D 0; > + } > + > if (to_vmx(vcpu)->nested.vmxon && !nested_cr4_valid(vcpu, cr4)) > return 1; >=20 > --=20 > 2.17.1 >=20 I haven=E2=80=99t seen a patch in the series that modifies kvm_set_cr4() = to verify CR4.CET is not set when CET is not reported as supported by = CPUID. I think that is missing from the series. -Liran