From: Chao Gao <chao.gao@intel.com>
To: Yang Weijiang <weijiang.yang@intel.com>
Cc: <seanjc@google.com>, <pbonzini@redhat.com>,
<dave.hansen@intel.com>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <x86@kernel.org>,
<yuan.yao@linux.intel.com>, <peterz@infradead.org>,
<rick.p.edgecombe@intel.com>, <mlevitsk@redhat.com>,
<john.allen@amd.com>
Subject: Re: [PATCH v9 22/27] KVM: VMX: Set up interception for CET MSRs
Date: Fri, 26 Jan 2024 11:54:16 +0800 [thread overview]
Message-ID: <ZbMs6KsCWqE0fpQv@chao-email> (raw)
In-Reply-To: <20240124024200.102792-23-weijiang.yang@intel.com>
On Tue, Jan 23, 2024 at 06:41:55PM -0800, Yang Weijiang wrote:
>Enable/disable CET MSRs interception per associated feature configuration.
>Shadow Stack feature requires all CET MSRs passed through to guest to make
>it supported in user and supervisor mode while IBT feature only depends on
>MSR_IA32_{U,S}_CETS_CET to enable user and supervisor IBT.
>
>Note, this MSR design introduced an architectural limitation of SHSTK and
>IBT control for guest, i.e., when SHSTK is exposed, IBT is also available
>to guest from architectual perspective since IBT relies on subset of SHSTK
>relevant MSRs.
>
>Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
>Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Chao Gao <chao.gao@intel.com>
one nit below,
>---
> arch/x86/kvm/vmx/vmx.c | 41 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
>diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
>index 064a5fe87948..34e91dbbffed 100644
>--- a/arch/x86/kvm/vmx/vmx.c
>+++ b/arch/x86/kvm/vmx/vmx.c
>@@ -692,6 +692,10 @@ static bool is_valid_passthrough_msr(u32 msr)
> case MSR_LBR_CORE_TO ... MSR_LBR_CORE_TO + 8:
> /* LBR MSRs. These are handled in vmx_update_intercept_for_lbr_msrs() */
> return true;
>+ case MSR_IA32_U_CET:
>+ case MSR_IA32_S_CET:
>+ case MSR_IA32_PL0_SSP ... MSR_IA32_INT_SSP_TAB:
>+ return true;
Please update the comment above vmx_possible_passthrough_msrs[] to indicate CET
MSRs are also handled separately.
> }
>
> r = possible_passthrough_msr_slot(msr) != -ENOENT;
>@@ -7767,6 +7771,41 @@ static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
> vmx->pt_desc.ctl_bitmask &= ~(0xfULL << (32 + i * 4));
> }
>
>+static void vmx_update_intercept_for_cet_msr(struct kvm_vcpu *vcpu)
>+{
>+ bool incpt;
>+
>+ if (kvm_cpu_cap_has(X86_FEATURE_SHSTK)) {
>+ incpt = !guest_cpuid_has(vcpu, X86_FEATURE_SHSTK);
>+
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_U_CET,
>+ MSR_TYPE_RW, incpt);
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_S_CET,
>+ MSR_TYPE_RW, incpt);
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_PL0_SSP,
>+ MSR_TYPE_RW, incpt);
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_PL1_SSP,
>+ MSR_TYPE_RW, incpt);
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_PL2_SSP,
>+ MSR_TYPE_RW, incpt);
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_PL3_SSP,
>+ MSR_TYPE_RW, incpt);
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_INT_SSP_TAB,
>+ MSR_TYPE_RW, incpt);
>+ if (!incpt)
>+ return;
>+ }
>+
>+ if (kvm_cpu_cap_has(X86_FEATURE_IBT)) {
>+ incpt = !guest_cpuid_has(vcpu, X86_FEATURE_IBT);
>+
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_U_CET,
>+ MSR_TYPE_RW, incpt);
>+ vmx_set_intercept_for_msr(vcpu, MSR_IA32_S_CET,
>+ MSR_TYPE_RW, incpt);
>+ }
>+}
>+
> static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
> {
> struct vcpu_vmx *vmx = to_vmx(vcpu);
>@@ -7845,6 +7884,8 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
>
> /* Refresh #PF interception to account for MAXPHYADDR changes. */
> vmx_update_exception_bitmap(vcpu);
>+
>+ vmx_update_intercept_for_cet_msr(vcpu);
> }
>
> static u64 vmx_get_perf_capabilities(void)
>--
>2.39.3
>
next prev parent reply other threads:[~2024-01-26 3:54 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-24 2:41 [PATCH v9 00/27] Enable CET Virtualization Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 01/27] x86/fpu/xstate: Always preserve non-user xfeatures/flags in __state_perm Yang Weijiang
2024-01-30 1:29 ` Edgecombe, Rick P
2024-01-24 2:41 ` [PATCH v9 02/27] x86/fpu/xstate: Refine CET user xstate bit enabling Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 03/27] x86/fpu/xstate: Add CET supervisor mode state support Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 04/27] x86/fpu/xstate: Introduce XFEATURE_MASK_KERNEL_DYNAMIC xfeature set Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 05/27] x86/fpu/xstate: Introduce fpu_guest_cfg for guest FPU configuration Yang Weijiang
2024-01-30 1:29 ` Edgecombe, Rick P
2024-01-30 15:00 ` Yang, Weijiang
2024-01-24 2:41 ` [PATCH v9 06/27] x86/fpu/xstate: Create guest fpstate with guest specific config Yang Weijiang
2024-01-30 1:38 ` Edgecombe, Rick P
2024-01-30 14:54 ` Yang, Weijiang
2024-01-24 2:41 ` [PATCH v9 07/27] x86/fpu/xstate: Warn if kernel dynamic xfeatures detected in normal fpstate Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 08/27] KVM: x86: Rework cpuid_get_supported_xcr0() to operate on vCPU data Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 09/27] KVM: x86: Rename kvm_{g,s}et_msr() to menifest emulation operations Yang Weijiang
2024-01-25 3:43 ` Chao Gao
2024-01-24 2:41 ` [PATCH v9 10/27] KVM: x86: Refine xsave-managed guest register/MSR reset handling Yang Weijiang
2024-01-25 10:17 ` Chao Gao
2024-01-26 9:13 ` Yang, Weijiang
2024-01-24 2:41 ` [PATCH v9 11/27] KVM: x86: Add kvm_msr_{read,write}() helpers Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 12/27] KVM: x86: Report XSS as to-be-saved if there are supported features Yang Weijiang
2024-01-25 10:37 ` Chao Gao
2024-01-24 2:41 ` [PATCH v9 13/27] KVM: x86: Refresh CPUID on write to guest MSR_IA32_XSS Yang Weijiang
2024-01-25 10:57 ` Chao Gao
2024-01-26 9:30 ` Yang, Weijiang
2024-01-24 2:41 ` [PATCH v9 14/27] KVM: x86: Initialize kvm_caps.supported_xss Yang Weijiang
2024-01-26 1:35 ` Chao Gao
2024-01-24 2:41 ` [PATCH v9 15/27] KVM: x86: Load guest FPU state when access XSAVE-managed MSRs Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 16/27] KVM: x86: Add fault checks for guest CR4.CET setting Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 17/27] KVM: x86: Report KVM supported CET MSRs as to-be-saved Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 18/27] KVM: VMX: Introduce CET VMCS fields and control bits Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 19/27] KVM: x86: Use KVM-governed feature framework to track "SHSTK/IBT enabled" Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 20/27] KVM: VMX: Emulate read and write to CET MSRs Yang Weijiang
2024-01-24 2:41 ` [PATCH v9 21/27] KVM: x86: Save and reload SSP to/from SMRAM Yang Weijiang
2024-01-26 3:17 ` Chao Gao
2024-01-26 6:51 ` Chao Gao
2024-01-24 2:41 ` [PATCH v9 22/27] KVM: VMX: Set up interception for CET MSRs Yang Weijiang
2024-01-26 3:54 ` Chao Gao [this message]
2024-01-26 9:36 ` Yang, Weijiang
2024-01-24 2:41 ` [PATCH v9 23/27] KVM: VMX: Set host constant supervisor states to VMCS fields Yang Weijiang
2024-01-26 6:31 ` Chao Gao
2024-01-26 9:37 ` Yang, Weijiang
2024-01-24 2:41 ` [PATCH v9 24/27] KVM: x86: Enable CET virtualization for VMX and advertise to userspace Yang Weijiang
2024-01-26 7:50 ` Chao Gao
2024-01-26 12:54 ` Yang, Weijiang
2024-01-24 2:41 ` [PATCH v9 25/27] KVM: nVMX: Introduce new VMX_BASIC bit for event error_code delivery to L1 Yang Weijiang
2024-01-26 7:54 ` Chao Gao
2024-01-24 2:41 ` [PATCH v9 26/27] KVM: nVMX: Enable CET support for nested guest Yang Weijiang
2024-01-29 7:04 ` Chao Gao
2024-01-30 7:38 ` Yang, Weijiang
2024-01-24 2:42 ` [PATCH v9 27/27] KVM: x86: Stop emulating for CET protected branch instructions Yang Weijiang
2024-01-26 8:53 ` Chao Gao
2024-01-26 12:56 ` Yang, Weijiang
2024-01-30 1:40 ` [PATCH v9 00/27] Enable CET Virtualization Edgecombe, Rick P
2024-01-30 15:05 ` Yang, Weijiang
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