diff options
| author | Yang Weijiang <weijiang.yang@intel.com> | 2025-09-19 15:32:22 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2025-09-23 09:11:22 -0700 |
| commit | 1a61bd0d126abbf01c384c44b46bcdd4ef495850 (patch) | |
| tree | ba7dc035e1f79293295788cdc9007e3359f73e42 | |
| parent | 8b59d0275c964bcbe573dde46bd3c1f20ed2d2bd (diff) | |
KVM: x86: Save and reload SSP to/from SMRAM
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.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Yang Weijiang <weijiang.yang@intel.com>
Tested-by: Mathias Krause <minipli@grsecurity.net>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Chao Gao <chao.gao@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20250919223258.1604852-16-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/smm.c | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/smm.h | 2 |
2 files changed, 9 insertions, 1 deletions
diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c index 5dd8a1646800..b0b14ba37f9a 100644 --- a/arch/x86/kvm/smm.c +++ b/arch/x86/kvm/smm.c @@ -269,6 +269,10 @@ 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 = kvm_x86_call(get_interrupt_shadow)(vcpu); + + if (guest_cpu_cap_has(vcpu, X86_FEATURE_SHSTK) && + kvm_msr_read(vcpu, MSR_KVM_INTERNAL_GUEST_SSP, &smram->ssp)) + kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); } #endif @@ -558,6 +562,10 @@ static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, kvm_x86_call(set_interrupt_shadow)(vcpu, 0); ctxt->interruptibility = (u8)smstate->int_shadow; + if (guest_cpu_cap_has(vcpu, X86_FEATURE_SHSTK) && + kvm_msr_write(vcpu, MSR_KVM_INTERNAL_GUEST_SSP, smstate->ssp)) + return X86EMUL_UNHANDLEABLE; + return X86EMUL_CONTINUE; } #endif diff --git a/arch/x86/kvm/smm.h b/arch/x86/kvm/smm.h index 551703fbe200..db3c88f16138 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; |