Add all CET MSRs including the synthesized GUEST_SSP to report list. PL{0,1,2}_SSP are independent to host XSAVE management with later patches. MSR_IA32_U_CET and MSR_IA32_PL3_SSP are XSAVE-managed on host side. MSR_IA32_S_CET/MSR_IA32_INT_SSP_TAB/MSR_KVM_GUEST_SSP are not XSAVE-managed. When CET IBT/SHSTK are enumerated to guest, both user and supervisor modes should be supported for architechtural integrity, i.e., two modes are supported as both or neither. Signed-off-by: Yang Weijiang <weijiang.yang@xxxxxxxxx> --- arch/x86/include/uapi/asm/kvm_para.h | 1 + arch/x86/kvm/x86.c | 10 ++++++++++ arch/x86/kvm/x86.h | 10 ++++++++++ 3 files changed, 21 insertions(+) diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h index 6e64b27b2c1e..7af465e4e0bd 100644 --- a/arch/x86/include/uapi/asm/kvm_para.h +++ b/arch/x86/include/uapi/asm/kvm_para.h @@ -58,6 +58,7 @@ #define MSR_KVM_ASYNC_PF_INT 0x4b564d06 #define MSR_KVM_ASYNC_PF_ACK 0x4b564d07 #define MSR_KVM_MIGRATION_CONTROL 0x4b564d08 +#define MSR_KVM_GUEST_SSP 0x4b564d09 struct kvm_steal_time { __u64 steal; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index be76ac6bbb21..59e961a88b75 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1463,6 +1463,9 @@ static const u32 msrs_to_save_base[] = { MSR_IA32_XFD, MSR_IA32_XFD_ERR, MSR_IA32_XSS, + MSR_IA32_U_CET, MSR_IA32_S_CET, + MSR_IA32_PL0_SSP, MSR_IA32_PL1_SSP, MSR_IA32_PL2_SSP, + MSR_IA32_PL3_SSP, MSR_IA32_INT_SSP_TAB, MSR_KVM_GUEST_SSP, }; static const u32 msrs_to_save_pmu[] = { @@ -7215,6 +7218,13 @@ static void kvm_probe_msr_to_save(u32 msr_index) if (!kvm_caps.supported_xss) return; break; + case MSR_IA32_U_CET: + case MSR_IA32_S_CET: + case MSR_KVM_GUEST_SSP: + case MSR_IA32_PL0_SSP ... MSR_IA32_INT_SSP_TAB: + if (!kvm_is_cet_supported()) + return; + break; default: break; } diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 82e3dafc5453..6e6292915f8c 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -362,6 +362,16 @@ static inline bool kvm_mpx_supported(void) == (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); } +#define CET_XSTATE_MASK (XFEATURE_MASK_CET_USER) +/* + * Shadow Stack and Indirect Branch Tracking feature enabling depends on + * whether host side CET user xstate bit is supported or not. + */ +static inline bool kvm_is_cet_supported(void) +{ + return (kvm_caps.supported_xss & CET_XSTATE_MASK) == CET_XSTATE_MASK; +} + extern unsigned int min_timer_period_us; extern bool enable_vmware_backdoor; -- 2.27.0