From: Yang Weijiang <weijiang.yang@intel.com>
To: 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
Cc: peterz@infradead.org, chao.gao@intel.com,
rick.p.edgecombe@intel.com, mlevitsk@redhat.com,
john.allen@amd.com, weijiang.yang@intel.com
Subject: [PATCH v9 21/27] KVM: x86: Save and reload SSP to/from SMRAM
Date: Tue, 23 Jan 2024 18:41:54 -0800 [thread overview]
Message-ID: <20240124024200.102792-22-weijiang.yang@intel.com> (raw)
In-Reply-To: <20240124024200.102792-1-weijiang.yang@intel.com>
Save CET SSP to SMRAM on SMI and reload it on RSM. KVM emulates HW arch
behavior when guest enters/leaves SMM mode,i.e., save registers to SMRAM
at the entry of SMM and reload them at the exit to SMM. Per SDM, SSP is
one of such registers on 64-bit Arch, and add the support for SSP. Note,
on 32-bit Arch, SSP is not defined in SMRAM, so fail 32-bit CET guest
launch.
Suggested-by: Sean Christopherson <seanjc@google.com>
Suggested-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/cpuid.c | 11 +++++++++++
arch/x86/kvm/smm.c | 8 ++++++++
arch/x86/kvm/smm.h | 2 +-
3 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 3ab133530573..95233b0879a3 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -149,6 +149,17 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu,
if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
return -EINVAL;
}
+ /*
+ * Prevent 32-bit guest launch if shadow stack is exposed as SSP
+ * state is not defined for 32-bit SMRAM.
+ */
+ best = cpuid_entry2_find(entries, nent, 0x80000001,
+ KVM_CPUID_INDEX_NOT_SIGNIFICANT);
+ if (best && !(best->edx & F(LM))) {
+ best = cpuid_entry2_find(entries, nent, 0x7, 0);
+ if (best && (best->ecx & F(SHSTK)))
+ return -EINVAL;
+ }
/*
* Exposing dynamic xfeatures to the guest requires additional
diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c
index 45c855389ea7..7aac9c54c353 100644
--- a/arch/x86/kvm/smm.c
+++ b/arch/x86/kvm/smm.c
@@ -275,6 +275,10 @@ static void enter_smm_save_state_64(struct kvm_vcpu *vcpu,
enter_smm_save_seg_64(vcpu, &smram->gs, VCPU_SREG_GS);
smram->int_shadow = static_call(kvm_x86_get_interrupt_shadow)(vcpu);
+
+ if (guest_can_use(vcpu, X86_FEATURE_SHSTK))
+ KVM_BUG_ON(kvm_msr_read(vcpu, MSR_KVM_SSP, &smram->ssp),
+ vcpu->kvm);
}
#endif
@@ -564,6 +568,10 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt,
static_call(kvm_x86_set_interrupt_shadow)(vcpu, 0);
ctxt->interruptibility = (u8)smstate->int_shadow;
+ if (guest_can_use(vcpu, X86_FEATURE_SHSTK))
+ KVM_BUG_ON(kvm_msr_write(vcpu, MSR_KVM_SSP, smstate->ssp),
+ vcpu->kvm);
+
return X86EMUL_CONTINUE;
}
#endif
diff --git a/arch/x86/kvm/smm.h b/arch/x86/kvm/smm.h
index a1cf2ac5bd78..1e2a3e18207f 100644
--- a/arch/x86/kvm/smm.h
+++ b/arch/x86/kvm/smm.h
@@ -116,8 +116,8 @@ struct kvm_smram_state_64 {
u32 smbase;
u32 reserved4[5];
- /* ssp and svm_* fields below are not implemented by KVM */
u64 ssp;
+ /* svm_* fields below are not implemented by KVM */
u64 svm_guest_pat;
u64 svm_host_efer;
u64 svm_host_cr4;
--
2.39.3
next prev parent reply other threads:[~2024-01-24 2:42 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 ` Yang Weijiang [this message]
2024-01-26 3:17 ` [PATCH v9 21/27] KVM: x86: Save and reload SSP to/from SMRAM 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
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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