Message ID | 20210203113421.5759-15-weijiang.yang@intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Introduce support for guest CET feature | expand |
On 03/02/21 12:34, Yang Weijiang wrote: > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 22eb6b8626a8..f63b713cd71f 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -8592,6 +8592,16 @@ static void enter_smm_save_state_64(struct kvm_vcpu *vcpu, char *buf) > > for (i = 0; i < 6; i++) > enter_smm_save_seg_64(vcpu, buf, i); > + > + if (kvm_cet_supported()) { > + struct msr_data msr; > + > + msr.index = MSR_KVM_GUEST_SSP; > + msr.host_initiated = true; > + /* GUEST_SSP is stored in VMCS at vm-exit. */ > + kvm_x86_ops.get_msr(vcpu, &msr); > + put_smstate(u64, buf, 0x7ec8, msr.data); > + } > } > #endif > > 0x7ec8 is used for I/O instruction restart and auto-halt restart. 0x7f08 is a free spot. We should really document the KVM state save area format. Paolo
On Wed, Feb 03, 2021 at 01:07:53PM +0100, Paolo Bonzini wrote: > On 03/02/21 12:34, Yang Weijiang wrote: > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index 22eb6b8626a8..f63b713cd71f 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -8592,6 +8592,16 @@ static void enter_smm_save_state_64(struct kvm_vcpu *vcpu, char *buf) > > for (i = 0; i < 6; i++) > > enter_smm_save_seg_64(vcpu, buf, i); > > + > > + if (kvm_cet_supported()) { > > + struct msr_data msr; > > + > > + msr.index = MSR_KVM_GUEST_SSP; > > + msr.host_initiated = true; > > + /* GUEST_SSP is stored in VMCS at vm-exit. */ > > + kvm_x86_ops.get_msr(vcpu, &msr); > > + put_smstate(u64, buf, 0x7ec8, msr.data); > > + } > > } > > #endif > > > > 0x7ec8 is used for I/O instruction restart and auto-halt restart. 0x7f08 is > a free spot. We should really document the KVM state save area format. Thanks for catching the documentation error! > > Paolo
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 56cae1ff9e3f..6d4a3181d8bd 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2615,6 +2615,17 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, return r; } + if (kvm_cet_supported()) { + struct msr_data msr; + + val = GET_SMSTATE(u64, smstate, 0x7ec8); + msr.index = MSR_KVM_GUEST_SSP; + msr.host_initiated = true; + msr.data = val; + /* Mimic host_initiated access to bypass ssp access check. */ + kvm_x86_ops.set_msr(ctxt->vcpu, &msr); + } + return X86EMUL_CONTINUE; } #endif diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 22eb6b8626a8..f63b713cd71f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8592,6 +8592,16 @@ static void enter_smm_save_state_64(struct kvm_vcpu *vcpu, char *buf) for (i = 0; i < 6; i++) enter_smm_save_seg_64(vcpu, buf, i); + + if (kvm_cet_supported()) { + struct msr_data msr; + + msr.index = MSR_KVM_GUEST_SSP; + msr.host_initiated = true; + /* GUEST_SSP is stored in VMCS at vm-exit. */ + kvm_x86_ops.get_msr(vcpu, &msr); + put_smstate(u64, buf, 0x7ec8, msr.data); + } } #endif
Save GUEST_SSP to SMRAM when guest exits to SMM due to SMI and restore it when guest exits SMM to interrupted normal non-root mode. Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> --- arch/x86/kvm/emulate.c | 11 +++++++++++ arch/x86/kvm/x86.c | 10 ++++++++++ 2 files changed, 21 insertions(+)