| Message ID | 20181226081532.30698-5-weijiang.yang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | This patch-set is to enable kvm Guest OS CET support. | expand |
On Wed, Dec 26, 2018 at 04:15:28PM +0800, Yang Weijiang wrote: > During Guest OS execution, it accesses these MSRs to > configure CET runtime settings. The changelog needs to explain why it's ok to expose these MSRS to the guest, e.g. call out which are saved/loaded through the VMCS and which are saved/loaded via XSAVES/XRSTORS. And maybe expand "runtime settings" to elaborate on when most guest kernels will access the MSRs, i.e. to justify exposing them to the guest. It should also clarify why IA32_PL1_SSP and IA32_PL2_SSP are NOT exposed to the guest. > > Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com> > Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> > --- > arch/x86/kvm/vmx.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 25fa6bd2fb95..fa2db6248404 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -11550,6 +11550,13 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) > vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_CS, MSR_TYPE_RW); > vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_ESP, MSR_TYPE_RW); > vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_EIP, MSR_TYPE_RW); > + > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_U_CET, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_S_CET, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_INT_SSP_TAB, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PL0_SSP, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PL3_SSP, MSR_TYPE_RW); > + > vmx->msr_bitmap_mode = 0; > > vmx->loaded_vmcs = &vmx->vmcs01; > -- > 2.17.1 >
On Wed, Dec 26, 2018 at 12:13 AM Yang Weijiang <weijiang.yang@intel.com> wrote: > > During Guest OS execution, it accesses these MSRs to > configure CET runtime settings. > > Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com> > Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> > --- > arch/x86/kvm/vmx.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 25fa6bd2fb95..fa2db6248404 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -11550,6 +11550,13 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) > vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_CS, MSR_TYPE_RW); > vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_ESP, MSR_TYPE_RW); > vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_EIP, MSR_TYPE_RW); > + > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_U_CET, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_S_CET, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_INT_SSP_TAB, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PL0_SSP, MSR_TYPE_RW); > + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PL3_SSP, MSR_TYPE_RW); > + Shouldn't this be conditional on the guest having CET support enumerated in CPUID? > vmx->msr_bitmap_mode = 0; > > vmx->loaded_vmcs = &vmx->vmcs01; > -- > 2.17.1 >
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 25fa6bd2fb95..fa2db6248404 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -11550,6 +11550,13 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id) vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_CS, MSR_TYPE_RW); vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_ESP, MSR_TYPE_RW); vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_SYSENTER_EIP, MSR_TYPE_RW); + + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_U_CET, MSR_TYPE_RW); + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_S_CET, MSR_TYPE_RW); + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_INT_SSP_TAB, MSR_TYPE_RW); + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PL0_SSP, MSR_TYPE_RW); + vmx_disable_intercept_for_msr(msr_bitmap, MSR_IA32_PL3_SSP, MSR_TYPE_RW); + vmx->msr_bitmap_mode = 0; vmx->loaded_vmcs = &vmx->vmcs01;