From da39556f66f5cfe8f9c989206974f1cb16ca5d7c Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 25 Apr 2018 22:04:25 -0400 Subject: x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest Expose the CPUID.7.EDX[31] bit to the guest, and also guard against various combinations of SPEC_CTRL MSR values. The handling of the MSR (to take into account the host value of SPEC_CTRL Bit(2)) is taken care of in patch: KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar --- arch/x86/kvm/cpuid.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/kvm/cpuid.c') diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 82055b90a8b3..376ac9a2a2b9 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -407,7 +407,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = - F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(RDS) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ -- cgit v1.2.3 From 9f65fb29374ee37856dbad847b4e121aab72b510 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 9 May 2018 21:41:38 +0200 Subject: x86/bugs: Rename _RDS to _SSBD Intel collateral will reference the SSB mitigation bit in IA32_SPEC_CTL[2] as SSBD (Speculative Store Bypass Disable). Hence changing it. It is unclear yet what the MSR_IA32_ARCH_CAPABILITIES (0x10a) Bit(4) name is going to be. Following the rename it would be SSBD_NO but that rolls out to Speculative Store Bypass Disable No. Also fixed the missing space in X86_FEATURE_AMD_SSBD. [ tglx: Fixup x86_amd_rds_enable() and rds_tif_to_amd_ls_cfg() as well ] Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/cpufeatures.h | 4 ++-- arch/x86/include/asm/msr-index.h | 10 +++++----- arch/x86/include/asm/spec-ctrl.h | 12 ++++++------ arch/x86/include/asm/thread_info.h | 6 +++--- arch/x86/kernel/cpu/amd.c | 14 +++++++------- arch/x86/kernel/cpu/bugs.c | 36 ++++++++++++++++++------------------ arch/x86/kernel/cpu/common.c | 2 +- arch/x86/kernel/cpu/intel.c | 2 +- arch/x86/kernel/process.c | 8 ++++---- arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/vmx.c | 6 +++--- 11 files changed, 51 insertions(+), 51 deletions(-) (limited to 'arch/x86/kvm/cpuid.c') diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index b2464c1787df..4e1c747acbf8 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -215,7 +215,7 @@ #define X86_FEATURE_USE_IBPB ( 7*32+21) /* "" Indirect Branch Prediction Barrier enabled */ #define X86_FEATURE_USE_IBRS_FW ( 7*32+22) /* "" Use IBRS during runtime firmware calls */ #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE ( 7*32+23) /* "" Disable Speculative Store Bypass. */ -#define X86_FEATURE_AMD_RDS (7*32+24) /* "" AMD RDS implementation */ +#define X86_FEATURE_AMD_SSBD ( 7*32+24) /* "" AMD SSBD implementation */ /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ @@ -336,7 +336,7 @@ #define X86_FEATURE_SPEC_CTRL (18*32+26) /* "" Speculation Control (IBRS + IBPB) */ #define X86_FEATURE_INTEL_STIBP (18*32+27) /* "" Single Thread Indirect Branch Predictors */ #define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */ -#define X86_FEATURE_RDS (18*32+31) /* Reduced Data Speculation */ +#define X86_FEATURE_SSBD (18*32+31) /* Speculative Store Bypass Disable */ /* * BUG word(s) diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 810f50bb338d..0da3ca260b06 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -42,8 +42,8 @@ #define MSR_IA32_SPEC_CTRL 0x00000048 /* Speculation Control */ #define SPEC_CTRL_IBRS (1 << 0) /* Indirect Branch Restricted Speculation */ #define SPEC_CTRL_STIBP (1 << 1) /* Single Thread Indirect Branch Predictors */ -#define SPEC_CTRL_RDS_SHIFT 2 /* Reduced Data Speculation bit */ -#define SPEC_CTRL_RDS (1 << SPEC_CTRL_RDS_SHIFT) /* Reduced Data Speculation */ +#define SPEC_CTRL_SSBD_SHIFT 2 /* Speculative Store Bypass Disable bit */ +#define SPEC_CTRL_SSBD (1 << SPEC_CTRL_SSBD_SHIFT) /* Speculative Store Bypass Disable */ #define MSR_IA32_PRED_CMD 0x00000049 /* Prediction Command */ #define PRED_CMD_IBPB (1 << 0) /* Indirect Branch Prediction Barrier */ @@ -70,10 +70,10 @@ #define MSR_IA32_ARCH_CAPABILITIES 0x0000010a #define ARCH_CAP_RDCL_NO (1 << 0) /* Not susceptible to Meltdown */ #define ARCH_CAP_IBRS_ALL (1 << 1) /* Enhanced IBRS support */ -#define ARCH_CAP_RDS_NO (1 << 4) /* +#define ARCH_CAP_SSBD_NO (1 << 4) /* * Not susceptible to Speculative Store Bypass - * attack, so no Reduced Data Speculation control - * required. + * attack, so no Speculative Store Bypass + * control required. */ #define MSR_IA32_BBL_CR_CTL 0x00000119 diff --git a/arch/x86/include/asm/spec-ctrl.h b/arch/x86/include/asm/spec-ctrl.h index 45ef00ad5105..dc21209790bf 100644 --- a/arch/x86/include/asm/spec-ctrl.h +++ b/arch/x86/include/asm/spec-ctrl.h @@ -17,20 +17,20 @@ extern void x86_spec_ctrl_restore_host(u64); /* AMD specific Speculative Store Bypass MSR data */ extern u64 x86_amd_ls_cfg_base; -extern u64 x86_amd_ls_cfg_rds_mask; +extern u64 x86_amd_ls_cfg_ssbd_mask; /* The Intel SPEC CTRL MSR base value cache */ extern u64 x86_spec_ctrl_base; -static inline u64 rds_tif_to_spec_ctrl(u64 tifn) +static inline u64 ssbd_tif_to_spec_ctrl(u64 tifn) { - BUILD_BUG_ON(TIF_RDS < SPEC_CTRL_RDS_SHIFT); - return (tifn & _TIF_RDS) >> (TIF_RDS - SPEC_CTRL_RDS_SHIFT); + BUILD_BUG_ON(TIF_SSBD < SPEC_CTRL_SSBD_SHIFT); + return (tifn & _TIF_SSBD) >> (TIF_SSBD - SPEC_CTRL_SSBD_SHIFT); } -static inline u64 rds_tif_to_amd_ls_cfg(u64 tifn) +static inline u64 ssbd_tif_to_amd_ls_cfg(u64 tifn) { - return (tifn & _TIF_RDS) ? x86_amd_ls_cfg_rds_mask : 0ULL; + return (tifn & _TIF_SSBD) ? x86_amd_ls_cfg_ssbd_mask : 0ULL; } extern void speculative_store_bypass_update(void); diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index e5c26cc59619..2ff2a30a264f 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -79,7 +79,7 @@ struct thread_info { #define TIF_SIGPENDING 2 /* signal pending */ #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ #define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/ -#define TIF_RDS 5 /* Reduced data speculation */ +#define TIF_SSBD 5 /* Reduced data speculation */ #define TIF_SYSCALL_EMU 6 /* syscall emulation active */ #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */ #define TIF_SECCOMP 8 /* secure computing */ @@ -106,7 +106,7 @@ struct thread_info { #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) #define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) -#define _TIF_RDS (1 << TIF_RDS) +#define _TIF_SSBD (1 << TIF_SSBD) #define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) #define _TIF_SECCOMP (1 << TIF_SECCOMP) @@ -146,7 +146,7 @@ struct thread_info { /* flags to check in __switch_to() */ #define _TIF_WORK_CTXSW \ - (_TIF_IO_BITMAP|_TIF_NOCPUID|_TIF_NOTSC|_TIF_BLOCKSTEP|_TIF_RDS) + (_TIF_IO_BITMAP|_TIF_NOCPUID|_TIF_NOTSC|_TIF_BLOCKSTEP|_TIF_SSBD) #define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY) #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 18efc33a8d2e..7bde990b0385 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -567,12 +567,12 @@ static void bsp_init_amd(struct cpuinfo_x86 *c) } /* * Try to cache the base value so further operations can - * avoid RMW. If that faults, do not enable RDS. + * avoid RMW. If that faults, do not enable SSBD. */ if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &x86_amd_ls_cfg_base)) { - setup_force_cpu_cap(X86_FEATURE_RDS); - setup_force_cpu_cap(X86_FEATURE_AMD_RDS); - x86_amd_ls_cfg_rds_mask = 1ULL << bit; + setup_force_cpu_cap(X86_FEATURE_SSBD); + setup_force_cpu_cap(X86_FEATURE_AMD_SSBD); + x86_amd_ls_cfg_ssbd_mask = 1ULL << bit; } } } @@ -920,9 +920,9 @@ static void init_amd(struct cpuinfo_x86 *c) if (!cpu_has(c, X86_FEATURE_XENPV)) set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); - if (boot_cpu_has(X86_FEATURE_AMD_RDS)) { - set_cpu_cap(c, X86_FEATURE_RDS); - set_cpu_cap(c, X86_FEATURE_AMD_RDS); + if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) { + set_cpu_cap(c, X86_FEATURE_SSBD); + set_cpu_cap(c, X86_FEATURE_AMD_SSBD); } } diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 563d8e54c863..09b116b7f3bf 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -45,10 +45,10 @@ static u64 __ro_after_init x86_spec_ctrl_mask = ~SPEC_CTRL_IBRS; /* * AMD specific MSR info for Speculative Store Bypass control. - * x86_amd_ls_cfg_rds_mask is initialized in identify_boot_cpu(). + * x86_amd_ls_cfg_ssbd_mask is initialized in identify_boot_cpu(). */ u64 __ro_after_init x86_amd_ls_cfg_base; -u64 __ro_after_init x86_amd_ls_cfg_rds_mask; +u64 __ro_after_init x86_amd_ls_cfg_ssbd_mask; void __init check_bugs(void) { @@ -146,7 +146,7 @@ u64 x86_spec_ctrl_get_default(void) u64 msrval = x86_spec_ctrl_base; if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) - msrval |= rds_tif_to_spec_ctrl(current_thread_info()->flags); + msrval |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags); return msrval; } EXPORT_SYMBOL_GPL(x86_spec_ctrl_get_default); @@ -159,7 +159,7 @@ void x86_spec_ctrl_set_guest(u64 guest_spec_ctrl) return; if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) - host |= rds_tif_to_spec_ctrl(current_thread_info()->flags); + host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags); if (host != guest_spec_ctrl) wrmsrl(MSR_IA32_SPEC_CTRL, guest_spec_ctrl); @@ -174,18 +174,18 @@ void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl) return; if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) - host |= rds_tif_to_spec_ctrl(current_thread_info()->flags); + host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags); if (host != guest_spec_ctrl) wrmsrl(MSR_IA32_SPEC_CTRL, host); } EXPORT_SYMBOL_GPL(x86_spec_ctrl_restore_host); -static void x86_amd_rds_enable(void) +static void x86_amd_ssb_disable(void) { - u64 msrval = x86_amd_ls_cfg_base | x86_amd_ls_cfg_rds_mask; + u64 msrval = x86_amd_ls_cfg_base | x86_amd_ls_cfg_ssbd_mask; - if (boot_cpu_has(X86_FEATURE_AMD_RDS)) + if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) wrmsrl(MSR_AMD64_LS_CFG, msrval); } @@ -473,7 +473,7 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void) enum ssb_mitigation mode = SPEC_STORE_BYPASS_NONE; enum ssb_mitigation_cmd cmd; - if (!boot_cpu_has(X86_FEATURE_RDS)) + if (!boot_cpu_has(X86_FEATURE_SSBD)) return mode; cmd = ssb_parse_cmdline(); @@ -507,7 +507,7 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void) /* * We have three CPU feature flags that are in play here: * - X86_BUG_SPEC_STORE_BYPASS - CPU is susceptible. - * - X86_FEATURE_RDS - CPU is able to turn off speculative store bypass + * - X86_FEATURE_SSBD - CPU is able to turn off speculative store bypass * - X86_FEATURE_SPEC_STORE_BYPASS_DISABLE - engage the mitigation */ if (mode == SPEC_STORE_BYPASS_DISABLE) { @@ -518,12 +518,12 @@ static enum ssb_mitigation_cmd __init __ssb_select_mitigation(void) */ switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_INTEL: - x86_spec_ctrl_base |= SPEC_CTRL_RDS; - x86_spec_ctrl_mask &= ~SPEC_CTRL_RDS; - x86_spec_ctrl_set(SPEC_CTRL_RDS); + x86_spec_ctrl_base |= SPEC_CTRL_SSBD; + x86_spec_ctrl_mask &= ~SPEC_CTRL_SSBD; + x86_spec_ctrl_set(SPEC_CTRL_SSBD); break; case X86_VENDOR_AMD: - x86_amd_rds_enable(); + x86_amd_ssb_disable(); break; } } @@ -556,16 +556,16 @@ static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl) if (task_spec_ssb_force_disable(task)) return -EPERM; task_clear_spec_ssb_disable(task); - update = test_and_clear_tsk_thread_flag(task, TIF_RDS); + update = test_and_clear_tsk_thread_flag(task, TIF_SSBD); break; case PR_SPEC_DISABLE: task_set_spec_ssb_disable(task); - update = !test_and_set_tsk_thread_flag(task, TIF_RDS); + update = !test_and_set_tsk_thread_flag(task, TIF_SSBD); break; case PR_SPEC_FORCE_DISABLE: task_set_spec_ssb_disable(task); task_set_spec_ssb_force_disable(task); - update = !test_and_set_tsk_thread_flag(task, TIF_RDS); + update = !test_and_set_tsk_thread_flag(task, TIF_SSBD); break; default: return -ERANGE; @@ -635,7 +635,7 @@ void x86_spec_ctrl_setup_ap(void) x86_spec_ctrl_set(x86_spec_ctrl_base & ~x86_spec_ctrl_mask); if (ssb_mode == SPEC_STORE_BYPASS_DISABLE) - x86_amd_rds_enable(); + x86_amd_ssb_disable(); } #ifdef CONFIG_SYSFS diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index e0517bcee446..9fbb388fadac 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -959,7 +959,7 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap); if (!x86_match_cpu(cpu_no_spec_store_bypass) && - !(ia32_cap & ARCH_CAP_RDS_NO)) + !(ia32_cap & ARCH_CAP_SSBD_NO)) setup_force_cpu_bug(X86_BUG_SPEC_STORE_BYPASS); if (x86_match_cpu(cpu_no_speculation)) diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index ef3f9c01c274..0eab6c89c8d9 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -189,7 +189,7 @@ static void early_init_intel(struct cpuinfo_x86 *c) setup_clear_cpu_cap(X86_FEATURE_STIBP); setup_clear_cpu_cap(X86_FEATURE_SPEC_CTRL); setup_clear_cpu_cap(X86_FEATURE_INTEL_STIBP); - setup_clear_cpu_cap(X86_FEATURE_RDS); + setup_clear_cpu_cap(X86_FEATURE_SSBD); } /* diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 397342725046..b77a091bf3b8 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -283,11 +283,11 @@ static __always_inline void __speculative_store_bypass_update(unsigned long tifn { u64 msr; - if (static_cpu_has(X86_FEATURE_AMD_RDS)) { - msr = x86_amd_ls_cfg_base | rds_tif_to_amd_ls_cfg(tifn); + if (static_cpu_has(X86_FEATURE_AMD_SSBD)) { + msr = x86_amd_ls_cfg_base | ssbd_tif_to_amd_ls_cfg(tifn); wrmsrl(MSR_AMD64_LS_CFG, msr); } else { - msr = x86_spec_ctrl_base | rds_tif_to_spec_ctrl(tifn); + msr = x86_spec_ctrl_base | ssbd_tif_to_spec_ctrl(tifn); wrmsrl(MSR_IA32_SPEC_CTRL, msr); } } @@ -329,7 +329,7 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, if ((tifp ^ tifn) & _TIF_NOCPUID) set_cpuid_faulting(!!(tifn & _TIF_NOCPUID)); - if ((tifp ^ tifn) & _TIF_RDS) + if ((tifp ^ tifn) & _TIF_SSBD) __speculative_store_bypass_update(tifn); } diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 376ac9a2a2b9..865c9a769864 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -407,7 +407,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 7.0.edx*/ const u32 kvm_cpuid_7_0_edx_x86_features = - F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(RDS) | + F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | F(SSBD) | F(ARCH_CAPABILITIES); /* all calls to cpuid_count() should be made on the same cpu */ diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 16a111e44691..9b8d80bf3889 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3525,7 +3525,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!msr_info->host_initiated && !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) && !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) && - !guest_cpuid_has(vcpu, X86_FEATURE_RDS)) + !guest_cpuid_has(vcpu, X86_FEATURE_SSBD)) return 1; msr_info->data = to_vmx(vcpu)->spec_ctrl; @@ -3645,11 +3645,11 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!msr_info->host_initiated && !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) && !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) && - !guest_cpuid_has(vcpu, X86_FEATURE_RDS)) + !guest_cpuid_has(vcpu, X86_FEATURE_SSBD)) return 1; /* The STIBP bit doesn't fault even if it's not advertised */ - if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_RDS)) + if (data & ~(SPEC_CTRL_IBRS | SPEC_CTRL_STIBP | SPEC_CTRL_SSBD)) return 1; vmx->spec_ctrl = data; -- cgit v1.2.3 From e7c587da125291db39ddf1f49b18e5970adbac17 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 2 May 2018 18:15:14 +0200 Subject: x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Intel and AMD have different CPUID bits hence for those use synthetic bits which get set on the respective vendor's in init_speculation_control(). So that debacles like what the commit message of c65732e4f721 ("x86/cpu: Restore CPUID_8000_0008_EBX reload") talks about don't happen anymore. Signed-off-by: Borislav Petkov Signed-off-by: Thomas Gleixner Reviewed-by: Konrad Rzeszutek Wilk Tested-by: Jörg Otte Cc: Linus Torvalds Cc: "Kirill A. Shutemov" Link: https://lkml.kernel.org/r/20180504161815.GG9257@pd.tnic --- arch/x86/include/asm/cpufeatures.h | 10 ++++++---- arch/x86/kernel/cpu/common.c | 14 ++++++++++---- arch/x86/kvm/cpuid.c | 10 +++++----- arch/x86/kvm/svm.c | 6 +++--- arch/x86/kvm/vmx.c | 9 ++------- 5 files changed, 26 insertions(+), 23 deletions(-) (limited to 'arch/x86/kvm/cpuid.c') diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 4e1c747acbf8..cb9bca8cecdc 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -198,7 +198,6 @@ #define X86_FEATURE_CAT_L2 ( 7*32+ 5) /* Cache Allocation Technology L2 */ #define X86_FEATURE_CDP_L3 ( 7*32+ 6) /* Code and Data Prioritization L3 */ #define X86_FEATURE_INVPCID_SINGLE ( 7*32+ 7) /* Effectively INVPCID && CR4.PCIDE=1 */ - #define X86_FEATURE_HW_PSTATE ( 7*32+ 8) /* AMD HW-PState */ #define X86_FEATURE_PROC_FEEDBACK ( 7*32+ 9) /* AMD ProcFeedbackInterface */ #define X86_FEATURE_SME ( 7*32+10) /* AMD Secure Memory Encryption */ @@ -216,6 +215,9 @@ #define X86_FEATURE_USE_IBRS_FW ( 7*32+22) /* "" Use IBRS during runtime firmware calls */ #define X86_FEATURE_SPEC_STORE_BYPASS_DISABLE ( 7*32+23) /* "" Disable Speculative Store Bypass. */ #define X86_FEATURE_AMD_SSBD ( 7*32+24) /* "" AMD SSBD implementation */ +#define X86_FEATURE_IBRS ( 7*32+25) /* Indirect Branch Restricted Speculation */ +#define X86_FEATURE_IBPB ( 7*32+26) /* Indirect Branch Prediction Barrier */ +#define X86_FEATURE_STIBP ( 7*32+27) /* Single Thread Indirect Branch Predictors */ /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ @@ -276,9 +278,9 @@ #define X86_FEATURE_CLZERO (13*32+ 0) /* CLZERO instruction */ #define X86_FEATURE_IRPERF (13*32+ 1) /* Instructions Retired Count */ #define X86_FEATURE_XSAVEERPTR (13*32+ 2) /* Always save/restore FP error pointers */ -#define X86_FEATURE_IBPB (13*32+12) /* Indirect Branch Prediction Barrier */ -#define X86_FEATURE_IBRS (13*32+14) /* Indirect Branch Restricted Speculation */ -#define X86_FEATURE_STIBP (13*32+15) /* Single Thread Indirect Branch Predictors */ +#define X86_FEATURE_AMD_IBPB (13*32+12) /* "" Indirect Branch Prediction Barrier */ +#define X86_FEATURE_AMD_IBRS (13*32+14) /* "" Indirect Branch Restricted Speculation */ +#define X86_FEATURE_AMD_STIBP (13*32+15) /* "" Single Thread Indirect Branch Predictors */ /* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */ #define X86_FEATURE_DTHERM (14*32+ 0) /* Digital Thermal Sensor */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 9fbb388fadac..e6cd38b20375 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -757,17 +757,23 @@ static void init_speculation_control(struct cpuinfo_x86 *c) * and they also have a different bit for STIBP support. Also, * a hypervisor might have set the individual AMD bits even on * Intel CPUs, for finer-grained selection of what's available. - * - * We use the AMD bits in 0x8000_0008 EBX as the generic hardware - * features, which are visible in /proc/cpuinfo and used by the - * kernel. So set those accordingly from the Intel bits. */ if (cpu_has(c, X86_FEATURE_SPEC_CTRL)) { set_cpu_cap(c, X86_FEATURE_IBRS); set_cpu_cap(c, X86_FEATURE_IBPB); } + if (cpu_has(c, X86_FEATURE_INTEL_STIBP)) set_cpu_cap(c, X86_FEATURE_STIBP); + + if (cpu_has(c, X86_FEATURE_AMD_IBRS)) + set_cpu_cap(c, X86_FEATURE_IBRS); + + if (cpu_has(c, X86_FEATURE_AMD_IBPB)) + set_cpu_cap(c, X86_FEATURE_IBPB); + + if (cpu_has(c, X86_FEATURE_AMD_STIBP)) + set_cpu_cap(c, X86_FEATURE_STIBP); } void get_cpu_cap(struct cpuinfo_x86 *c) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 865c9a769864..e5ba48599428 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -379,7 +379,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 0x80000008.ebx */ const u32 kvm_cpuid_8000_0008_ebx_x86_features = - F(IBPB) | F(IBRS); + F(AMD_IBPB) | F(AMD_IBRS); /* cpuid 0xC0000001.edx */ const u32 kvm_cpuid_C000_0001_edx_x86_features = @@ -648,10 +648,10 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, entry->eax = g_phys_as | (virt_as << 8); entry->edx = 0; /* IBRS and IBPB aren't necessarily present in hardware cpuid */ - if (boot_cpu_has(X86_FEATURE_IBPB)) - entry->ebx |= F(IBPB); - if (boot_cpu_has(X86_FEATURE_IBRS)) - entry->ebx |= F(IBRS); + if (boot_cpu_has(X86_FEATURE_AMD_IBPB)) + entry->ebx |= F(AMD_IBPB); + if (boot_cpu_has(X86_FEATURE_AMD_IBRS)) + entry->ebx |= F(AMD_IBRS); entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); break; diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index fa891c8af842..1a7a811118a8 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -4108,7 +4108,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_SPEC_CTRL: if (!msr_info->host_initiated && - !guest_cpuid_has(vcpu, X86_FEATURE_IBRS)) + !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS)) return 1; msr_info->data = svm->spec_ctrl; @@ -4203,7 +4203,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) break; case MSR_IA32_SPEC_CTRL: if (!msr->host_initiated && - !guest_cpuid_has(vcpu, X86_FEATURE_IBRS)) + !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS)) return 1; /* The STIBP bit doesn't fault even if it's not advertised */ @@ -4230,7 +4230,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) break; case MSR_IA32_PRED_CMD: if (!msr->host_initiated && - !guest_cpuid_has(vcpu, X86_FEATURE_IBPB)) + !guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB)) return 1; if (data & ~PRED_CMD_IBPB) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9b8d80bf3889..210e1b63d4b5 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3523,9 +3523,7 @@ static int vmx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return kvm_get_msr_common(vcpu, msr_info); case MSR_IA32_SPEC_CTRL: if (!msr_info->host_initiated && - !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) && - !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) && - !guest_cpuid_has(vcpu, X86_FEATURE_SSBD)) + !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL)) return 1; msr_info->data = to_vmx(vcpu)->spec_ctrl; @@ -3643,9 +3641,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_SPEC_CTRL: if (!msr_info->host_initiated && - !guest_cpuid_has(vcpu, X86_FEATURE_IBRS) && - !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) && - !guest_cpuid_has(vcpu, X86_FEATURE_SSBD)) + !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL)) return 1; /* The STIBP bit doesn't fault even if it's not advertised */ @@ -3675,7 +3671,6 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_PRED_CMD: if (!msr_info->host_initiated && - !guest_cpuid_has(vcpu, X86_FEATURE_IBPB) && !guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL)) return 1; -- cgit v1.2.3 From bc226f07dcd3c9ef0b7f6236fe356ea4a9cb4769 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Thu, 10 May 2018 22:06:39 +0200 Subject: KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD Expose the new virtualized architectural mechanism, VIRT_SSBD, for using speculative store bypass disable (SSBD) under SVM. This will allow guests to use SSBD on hardware that uses non-architectural mechanisms for enabling SSBD. [ tglx: Folded the migration fixup from Paolo Bonzini ] Signed-off-by: Tom Lendacky Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kernel/cpu/common.c | 3 ++- arch/x86/kvm/cpuid.c | 11 +++++++++-- arch/x86/kvm/svm.c | 21 +++++++++++++++++++-- arch/x86/kvm/vmx.c | 18 +++++++++++++++--- arch/x86/kvm/x86.c | 13 ++++--------- 6 files changed, 50 insertions(+), 18 deletions(-) (limited to 'arch/x86/kvm/cpuid.c') diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index c25775fad4ed..f4b2588865e9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -924,7 +924,7 @@ struct kvm_x86_ops { int (*hardware_setup)(void); /* __init */ void (*hardware_unsetup)(void); /* __exit */ bool (*cpu_has_accelerated_tpr)(void); - bool (*cpu_has_high_real_mode_segbase)(void); + bool (*has_emulated_msr)(int index); void (*cpuid_update)(struct kvm_vcpu *vcpu); struct kvm *(*vm_alloc)(void); diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 68282514c025..b4247ed0c81e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -767,7 +767,8 @@ static void init_speculation_control(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_INTEL_STIBP)) set_cpu_cap(c, X86_FEATURE_STIBP); - if (cpu_has(c, X86_FEATURE_SPEC_CTRL_SSBD)) + if (cpu_has(c, X86_FEATURE_SPEC_CTRL_SSBD) || + cpu_has(c, X86_FEATURE_VIRT_SSBD)) set_cpu_cap(c, X86_FEATURE_SSBD); if (cpu_has(c, X86_FEATURE_AMD_IBRS)) { diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index e5ba48599428..ced851169730 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -379,7 +379,7 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, /* cpuid 0x80000008.ebx */ const u32 kvm_cpuid_8000_0008_ebx_x86_features = - F(AMD_IBPB) | F(AMD_IBRS); + F(AMD_IBPB) | F(AMD_IBRS) | F(VIRT_SSBD); /* cpuid 0xC0000001.edx */ const u32 kvm_cpuid_C000_0001_edx_x86_features = @@ -647,13 +647,20 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, g_phys_as = phys_as; entry->eax = g_phys_as | (virt_as << 8); entry->edx = 0; - /* IBRS and IBPB aren't necessarily present in hardware cpuid */ + /* + * IBRS, IBPB and VIRT_SSBD aren't necessarily present in + * hardware cpuid + */ if (boot_cpu_has(X86_FEATURE_AMD_IBPB)) entry->ebx |= F(AMD_IBPB); if (boot_cpu_has(X86_FEATURE_AMD_IBRS)) entry->ebx |= F(AMD_IBRS); + if (boot_cpu_has(X86_FEATURE_VIRT_SSBD)) + entry->ebx |= F(VIRT_SSBD); entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); + if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD)) + entry->ebx |= F(VIRT_SSBD); break; } case 0x80000019: diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index c07dbcc6d449..26110c202b19 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -4120,6 +4120,13 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = svm->spec_ctrl; break; + case MSR_AMD64_VIRT_SPEC_CTRL: + if (!msr_info->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_VIRT_SSBD)) + return 1; + + msr_info->data = svm->virt_spec_ctrl; + break; case MSR_F15H_IC_CFG: { int family, model; @@ -4251,6 +4258,16 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) break; set_msr_interception(svm->msrpm, MSR_IA32_PRED_CMD, 0, 1); break; + case MSR_AMD64_VIRT_SPEC_CTRL: + if (!msr->host_initiated && + !guest_cpuid_has(vcpu, X86_FEATURE_VIRT_SSBD)) + return 1; + + if (data & ~SPEC_CTRL_SSBD) + return 1; + + svm->virt_spec_ctrl = data; + break; case MSR_STAR: svm->vmcb->save.star = data; break; @@ -5791,7 +5808,7 @@ static bool svm_cpu_has_accelerated_tpr(void) return false; } -static bool svm_has_high_real_mode_segbase(void) +static bool svm_has_emulated_msr(int index) { return true; } @@ -7017,7 +7034,7 @@ static struct kvm_x86_ops svm_x86_ops __ro_after_init = { .hardware_enable = svm_hardware_enable, .hardware_disable = svm_hardware_disable, .cpu_has_accelerated_tpr = svm_cpu_has_accelerated_tpr, - .cpu_has_high_real_mode_segbase = svm_has_high_real_mode_segbase, + .has_emulated_msr = svm_has_emulated_msr, .vcpu_create = svm_create_vcpu, .vcpu_free = svm_free_vcpu, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 5d733a03a6fa..0c57fb4df2d1 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -9477,9 +9477,21 @@ static void vmx_handle_external_intr(struct kvm_vcpu *vcpu) } STACK_FRAME_NON_STANDARD(vmx_handle_external_intr); -static bool vmx_has_high_real_mode_segbase(void) +static bool vmx_has_emulated_msr(int index) { - return enable_unrestricted_guest || emulate_invalid_guest_state; + switch (index) { + case MSR_IA32_SMBASE: + /* + * We cannot do SMM unless we can run the guest in big + * real mode. + */ + return enable_unrestricted_guest || emulate_invalid_guest_state; + case MSR_AMD64_VIRT_SPEC_CTRL: + /* This is AMD only. */ + return false; + default: + return true; + } } static bool vmx_mpx_supported(void) @@ -12625,7 +12637,7 @@ static struct kvm_x86_ops vmx_x86_ops __ro_after_init = { .hardware_enable = hardware_enable, .hardware_disable = hardware_disable, .cpu_has_accelerated_tpr = report_flexpriority, - .cpu_has_high_real_mode_segbase = vmx_has_high_real_mode_segbase, + .has_emulated_msr = vmx_has_emulated_msr, .vm_init = vmx_vm_init, .vm_alloc = vmx_vm_alloc, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 51ecd381793b..421a39e40d5e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1058,6 +1058,7 @@ static u32 emulated_msrs[] = { MSR_SMI_COUNT, MSR_PLATFORM_INFO, MSR_MISC_FEATURES_ENABLES, + MSR_AMD64_VIRT_SPEC_CTRL, }; static unsigned num_emulated_msrs; @@ -2903,7 +2904,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) * fringe case that is not enabled except via specific settings * of the module parameters. */ - r = kvm_x86_ops->cpu_has_high_real_mode_segbase(); + r = kvm_x86_ops->has_emulated_msr(MSR_IA32_SMBASE); break; case KVM_CAP_VAPIC: r = !kvm_x86_ops->cpu_has_accelerated_tpr(); @@ -4603,14 +4604,8 @@ static void kvm_init_msr_list(void) num_msrs_to_save = j; for (i = j = 0; i < ARRAY_SIZE(emulated_msrs); i++) { - switch (emulated_msrs[i]) { - case MSR_IA32_SMBASE: - if (!kvm_x86_ops->cpu_has_high_real_mode_segbase()) - continue; - break; - default: - break; - } + if (!kvm_x86_ops->has_emulated_msr(emulated_msrs[i])) + continue; if (j < i) emulated_msrs[j] = emulated_msrs[i]; -- cgit v1.2.3