diff options
38 files changed, 105 insertions, 547 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c57316f230de..4e2373e0c0cb 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1079,12 +1079,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nopku [X86] Disable Memory Protection Keys CPU feature found in some Intel CPUs. - eagerfpu= [X86] - on enable eager fpu restore - off disable eager fpu restore - auto selects the default scheme, which automatically - enables eagerfpu restore for xsaveopt. - module.async_probe [KNL] Enable asynchronous probe on this module. diff --git a/arch/x86/crypto/crc32c-intel_glue.c b/arch/x86/crypto/crc32c-intel_glue.c index 0857b1a1de3b..c194d5717ae5 100644 --- a/arch/x86/crypto/crc32c-intel_glue.c +++ b/arch/x86/crypto/crc32c-intel_glue.c @@ -48,26 +48,13 @@ #ifdef CONFIG_X86_64 /* * use carryless multiply version of crc32c when buffer - * size is >= 512 (when eager fpu is enabled) or - * >= 1024 (when eager fpu is disabled) to account + * size is >= 512 to account * for fpu state save/restore overhead. */ -#define CRC32C_PCL_BREAKEVEN_EAGERFPU 512 -#define CRC32C_PCL_BREAKEVEN_NOEAGERFPU 1024 +#define CRC32C_PCL_BREAKEVEN 512 asmlinkage unsigned int crc_pcl(const u8 *buffer, int len, unsigned int crc_init); -static int crc32c_pcl_breakeven = CRC32C_PCL_BREAKEVEN_EAGERFPU; -#if defined(X86_FEATURE_EAGER_FPU) -#define set_pcl_breakeven_point() \ -do { \ - if (!use_eager_fpu()) \ - crc32c_pcl_breakeven = CRC32C_PCL_BREAKEVEN_NOEAGERFPU; \ -} while (0) -#else -#define set_pcl_breakeven_point() \ - (crc32c_pcl_breakeven = CRC32C_PCL_BREAKEVEN_NOEAGERFPU) -#endif #endif /* CONFIG_X86_64 */ static u32 crc32c_intel_le_hw_byte(u32 crc, unsigned char const *data, size_t length) @@ -190,7 +177,7 @@ static int crc32c_pcl_intel_update(struct shash_desc *desc, const u8 *data, * use faster PCL version if datasize is large enough to * overcome kernel fpu state save/restore overhead */ - if (len >= crc32c_pcl_breakeven && irq_fpu_usable()) { + if (len >= CRC32C_PCL_BREAKEVEN && irq_fpu_usable()) { kernel_fpu_begin(); *crcp = crc_pcl(data, len, *crcp); kernel_fpu_end(); @@ -202,7 +189,7 @@ static int crc32c_pcl_intel_update(struct shash_desc *desc, const u8 *data, static int __crc32c_pcl_intel_finup(u32 *crcp, const u8 *data, unsigned int len, u8 *out) { - if (len >= crc32c_pcl_breakeven && irq_fpu_usable()) { + if (len >= CRC32C_PCL_BREAKEVEN && irq_fpu_usable()) { kernel_fpu_begin(); *(__le32 *)out = ~cpu_to_le32(crc_pcl(data, len, *crcp)); kernel_fpu_end(); @@ -261,7 +248,6 @@ static int __init crc32c_intel_mod_init(void) alg.update = crc32c_pcl_intel_update; alg.finup = crc32c_pcl_intel_finup; alg.digest = crc32c_pcl_intel_digest; - set_pcl_breakeven_point(); } #endif return crypto_register_shash(&alg); diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 4dba597c5807..e83f972b0a14 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -104,7 +104,6 @@ #define X86_FEATURE_EXTD_APICID ( 3*32+26) /* has extended APICID (8 bits) */ #define X86_FEATURE_AMD_DCM ( 3*32+27) /* multi-node processor */ #define X86_FEATURE_APERFMPERF ( 3*32+28) /* APERFMPERF */ -#define X86_FEATURE_EAGER_FPU ( 3*32+29) /* "eagerfpu" Non lazy FPU restore */ #define X86_FEATURE_NONSTOP_TSC_S3 ( 3*32+30) /* TSC doesn't stop in S3 state */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 1429a7c736db..0877ae018fc9 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -27,16 +27,6 @@ extern void kernel_fpu_end(void); extern bool irq_fpu_usable(void); /* - * Some instructions like VIA's padlock instructions generate a spurious - * DNA fault but don't modify SSE registers. And these instructions - * get used from interrupt context as well. To prevent these kernel instructions - * in interrupt context interacting wrongly with other user/kernel fpu usage, we - * should use them only in the context of irq_ts_save/restore() - */ -extern int irq_ts_save(void); -extern void irq_ts_restore(int TS_state); - -/* * Query the presence of one or more xfeatures. Works on any legacy CPU as well. * * If 'feature_name' is set then put a human-readable description of diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 2737366ea583..d4a684997497 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -60,11 +60,6 @@ extern u64 fpu__get_supported_xfeatures_mask(void); /* * FPU related CPU feature flag helper routines: */ -static __always_inline __pure bool use_eager_fpu(void) -{ - return static_cpu_has(X86_FEATURE_EAGER_FPU); -} - static __always_inline __pure bool use_xsaveopt(void) { return static_cpu_has(X86_FEATURE_XSAVEOPT); @@ -484,42 +479,42 @@ extern int copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size) DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); /* - * Must be run with preemption disabled: this clears the fpu_fpregs_owner_ctx, - * on this CPU. + * The in-register FPU state for an FPU context on a CPU is assumed to be + * valid if the fpu->last_cpu matches the CPU, and the fpu_fpregs_owner_ctx + * matches the FPU. * - * This will disable any lazy FPU state restore of the current FPU state, - * but if the current thread owns the FPU, it will still be saved by. + * If the FPU register state is valid, the kernel can skip restoring the + * FPU state from memory. + * + * Any code that clobbers the FPU registers or updates the in-memory + * FPU state for a task MUST let the rest of the kernel know that the + * FPU registers are no longer valid for this task. + * + * Either one of these invalidation functions is enough. Invalidate + * a resource you control: CPU if using the CPU for something else + * (with preemption disabled), FPU for the current task, or a task that + * is prevented from running by the current task. */ -static inline void __cpu_disable_lazy_restore(unsigned int cpu) +static inline void __cpu_invalidate_fpregs_state(void) { - per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL; + __this_cpu_write(fpu_fpregs_owner_ctx, NULL); } -static inline int fpu_want_lazy_restore(struct fpu *fpu, unsigned int cpu) -{ - return fpu == this_cpu_read_stable(fpu_fpregs_owner_ctx) && cpu == fpu->last_cpu; -} - - -/* - * Wrap lazy FPU TS handling in a 'hw fpregs activation/deactivation' - * idiom, which is then paired with the sw-flag (fpregs_active) later on: - */ - -static inline void __fpregs_activate_hw(void) +static inline void __fpu_invalidate_fpregs_state(struct fpu *fpu) { - if (!use_eager_fpu()) - clts(); + fpu->last_cpu = -1; } -static inline void __fpregs_deactivate_hw(void) +static inline int fpregs_state_valid(struct fpu *fpu, unsigned int cpu) { - if (!use_eager_fpu()) - stts(); + return fpu == this_cpu_read_stable(fpu_fpregs_owner_ctx) && cpu == fpu->last_cpu; } -/* Must be paired with an 'stts' (fpregs_deactivate_hw()) after! */ -static inline void __fpregs_deactivate(struct fpu *fpu) +/* + * These generally need preemption protection to work, + * do try to avoid using these on their own: + */ +static inline void fpregs_deactivate(struct fpu *fpu) { WARN_ON_FPU(!fpu->fpregs_active); @@ -528,8 +523,7 @@ static inline void __fpregs_deactivate(struct fpu *fpu) trace_x86_fpu_regs_deactivated(fpu); } -/* Must be paired with a 'clts' (fpregs_activate_hw()) before! */ -static inline void __fpregs_activate(struct fpu *fpu) +static inline void fpregs_activate(struct fpu *fpu) { WARN_ON_FPU(fpu->fpregs_active); @@ -554,51 +548,19 @@ static inline int fpregs_active(void) } /* - * Encapsulate the CR0.TS handling together with the - * software flag. - * - * These generally need preemption protection to work, - * do try to avoid using these on their own. - */ -static inline void fpregs_activate(struct fpu *fpu) -{ - __fpregs_activate_hw(); - __fpregs_activate(fpu); -} - -static inline void fpregs_deactivate(struct fpu *fpu) -{ - __fpregs_deactivate(fpu); - __fpregs_deactivate_hw(); -} - -/* * FPU state switching for scheduling. * * This is a two-stage process: * - * - switch_fpu_prepare() saves the old state and - * sets the new state of the CR0.TS bit. This is - * done within the context of the old process. + * - switch_fpu_prepare() saves the old state. + * This is done within the context of the old process. * * - switch_fpu_finish() restores the new state as * necessary. */ -typedef struct { int preload; } fpu_switch_t; - -static inline fpu_switch_t -switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu) +static inline void +switch_fpu_prepare(struct fpu *old_fpu, int cpu) { - fpu_switch_t fpu; - - /* - * If the task has used the math, pre-load the FPU on xsave processors - * or if the past 5 consecutive context-switches used math. - */ - fpu.preload = static_cpu_has(X86_FEATURE_FPU) && - new_fpu->fpstate_active && - (use_eager_fpu() || new_fpu->counter > 5); - if (old_fpu->fpregs_active) { if (!copy_fpregs_to_fpstate(old_fpu)) old_fpu->last_cpu = -1; @@ -608,29 +570,8 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu) /* But leave fpu_fpregs_owner_ctx! */ old_fpu->fpregs_active = 0; trace_x86_fpu_regs_deactivated(old_fpu); - - /* Don't change CR0.TS if we just switch! */ - if (fpu.preload) { - new_fpu->counter++; - __fpregs_activate(new_fpu); - trace_x86_fpu_regs_activated(new_fpu); - prefetch(&new_fpu->state); - } else { - __fpregs_deactivate_hw(); - } - } else { - old_fpu->counter = 0; + } else old_fpu->last_cpu = -1; - if (fpu.preload) { - new_fpu->counter++; - if (fpu_want_lazy_restore(new_fpu, cpu)) - fpu.preload = 0; - else - prefetch(&new_fpu->state); - fpregs_activate(new_fpu); - } - } - return fpu; } /* @@ -638,15 +579,19 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu) */ /* - * By the time this gets called, we've already cleared CR0.TS and - * given the process the FPU if we are going to preload the FPU - * state - all we need to do is to conditionally restore the register - * state itself. + * Set up the userspace FPU context for the new task, if the task + * has used the FPU. */ -static inline void switch_fpu_finish(struct fpu *new_fpu, fpu_switch_t fpu_switch) +static inline void switch_fpu_finish(struct fpu *new_fpu, int cpu) { - if (fpu_switch.preload) - copy_kernel_to_fpregs(&new_fpu->state); + bool preload = static_cpu_has(X86_FEATURE_FPU) && + new_fpu->fpstate_active; + + if (preload) { + if (!fpregs_state_valid(new_fpu, cpu)) + copy_kernel_to_fpregs(&new_fpu->state); + fpregs_activate(new_fpu); + } } /* diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index 48df486b02f9..3c80f5b9c09d 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -322,17 +322,6 @@ struct fpu { unsigned char fpregs_active; /* - * @counter: - * - * This counter contains the number of consecutive context switches - * during which the FPU stays used. If this is over a threshold, the - * lazy FPU restore logic becomes eager, to save the trap overhead. - * This is an unsigned char so that after 256 iterations the counter - * wraps and the context switch behavior turns lazy again; this is to - * deal with bursty apps that only use the FPU for a short time: - */ - unsigned char counter; - /* * @state: * * In-memory copy of all FPU registers that we save/restore @@ -340,29 +329,6 @@ struct fpu { * the registers in the FPU are more recent than this state * copy. If the task context-switches away then they get * saved here and represent the FPU state. - * - * After context switches there may be a (short) time period - * during which the in-FPU hardware registers are unchanged - * and still perfectly match this state, if the tasks - * scheduled afterwards are not using the FPU. - * - * This is the 'lazy restore' window of optimization, which - * we track though 'fpu_fpregs_owner_ctx' and 'fpu->last_cpu'. - * - * We detect whether a subsequent task uses the FPU via setting - * CR0::TS to 1, which causes any FPU use to raise a #NM fault. - * - * During this window, if the task gets scheduled again, we - * might be able to skip having to do a restore from this - * memory buffer to the hardware registers - at the cost of - * incurring the overhead of #NM fault traps. - * - * Note that on modern CPUs that support the XSAVEOPT (or other - * optimized XSAVE instructions), we don't use #NM traps anymore, - * as the hardware can track whether FPU registers need saving - * or not. On such CPUs we activate the non-lazy ('eagerfpu') - * logic, which unconditionally saves/restores all FPU state - * across context switches. (if FPU state exists.) */ union fpregs_state state; /* diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 430bacf73074..1b2799e0699a 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -21,21 +21,16 @@ /* Supervisor features */ #define XFEATURE_MASK_SUPERVISOR (XFEATURE_MASK_PT) -/* Supported features which support lazy state saving */ -#define XFEATURE_MASK_LAZY (XFEATURE_MASK_FP | \ +/* All currently supported features */ +#define XCNTXT_MASK (XFEATURE_MASK_FP | \ XFEATURE_MASK_SSE | \ XFEATURE_MASK_YMM | \ XFEATURE_MASK_OPMASK | \ XFEATURE_MASK_ZMM_Hi256 | \ - XFEATURE_MASK_Hi16_ZMM) - -/* Supported features which require eager state saving */ -#define XFEATURE_MASK_EAGER (XFEATURE_MASK_BNDREGS | \ - XFEATURE_MASK_BNDCSR | \ - XFEATURE_MASK_PKRU) - -/* All currently supported features */ -#define XCNTXT_MASK (XFEATURE_MASK_LAZY | XFEATURE_MASK_EAGER) + XFEATURE_MASK_Hi16_ZMM | \ + XFEATURE_MASK_PKRU | \ + XFEATURE_MASK_BNDREGS | \ + XFEATURE_MASK_BNDCSR) #ifdef CONFIG_X86_64 #define REX_PREFIX "0x48, " diff --git a/arch/x86/include/asm/lguest_hcall.h b/arch/x86/include/asm/lguest_hcall.h index ef01fef3eebc..6c119cfae218 100644 --- a/arch/x86/include/asm/lguest_hcall.h +++ b/arch/x86/include/asm/lguest_hcall.h @@ -9,7 +9,6 @@ #define LHCALL_FLUSH_TLB 5 #define LHCALL_LOAD_IDT_ENTRY 6 #define LHCALL_SET_STACK 7 -#define LHCALL_TS 8 #define LHCALL_SET_CLOCKEVENT 9 #define LHCALL_HALT 10 #define LHCALL_SET_PMD 13 diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index 6108b1fada2b..1eea6ca40694 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -41,11 +41,6 @@ static inline void set_debugreg(unsigned long val, int reg) PVOP_VCALL2(pv_cpu_ops.set_debugreg, reg, val); } -static inline void clts(void) -{ - PVOP_VCALL0(pv_cpu_ops.clts); -} - static inline unsigned long read_cr0(void) { return PVOP_CALL0(unsigned long, pv_cpu_ops.read_cr0); diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 3f2bc0f0d3e8..bb2de45a60f2 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -103,8 +103,6 @@ struct pv_cpu_ops { unsigned long (*get_debugreg)(int regno); void (*set_debugreg)(int regno, unsigned long value); - void (*clts)(void); - unsigned long (*read_cr0)(void); void (*write_cr0)(unsigned long); diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index 19a2224f9e16..12af3e35edfa 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -6,11 +6,6 @@ #include <asm/nops.h> -static inline void native_clts(void) -{ - asm volatile("clts"); -} - /* * Volatile isn't enough to prevent the compiler from reordering the * read/write functions for the control registers and messing everything up. @@ -208,16 +203,8 @@ static inline void load_gs_index(unsigned selector) #endif -/* Clear the 'TS' bit */ -static inline void clts(void) -{ - native_clts(); -} - #endif/* CONFIG_PARAVIRT */ -#define stts() write_cr0(read_cr0() | X86_CR0_TS) - static inline void clflush(volatile void *__p) { asm volatile("clflush %0" : "+m" (*(volatile char __force *)__p)); diff --git a/arch/x86/include/asm/trace/fpu.h b/arch/x86/include/asm/trace/fpu.h index 9217ab1f5bf6..342e59789fcd 100644 --- a/arch/x86/include/asm/trace/fpu.h +++ b/arch/x86/include/asm/trace/fpu.h @@ -14,7 +14,6 @@ DECLARE_EVENT_CLASS(x86_fpu, __field(struct fpu *, fpu) __field(bool, fpregs_active) __field(bool, fpstate_active) - __field(int, counter) __field(u64, xfeatures) __field(u64, xcomp_bv) ), @@ -23,17 +22,15 @@ DECLARE_EVENT_CLASS(x86_fpu, __entry->fpu = fpu; __entry->fpregs_active = fpu->fpregs_active; __entry->fpstate_active = fpu->fpstate_active; - __entry->counter = fpu->counter; if (boot_cpu_has(X86_FEATURE_OSXSAVE)) { __entry->xfeatures = fpu->state.xsave.header.xfeatures; __entry->xcomp_bv = fpu->state.xsave.header.xcomp_bv; } ), - TP_printk("x86/fpu: %p fpregs_active: %d fpstate_active: %d counter: %d xfeatures: %llx xcomp_bv: %llx", + TP_printk("x86/fpu: %p fpregs_active: %d fpstate_active: %d xfeatures: %llx xcomp_bv: %llx", __entry->fpu, __entry->fpregs_active, __entry->fpstate_active, - __entry->counter, __entry->xfeatures, __entry->xcomp_bv ) diff --git a/arch/x86/kernel/fpu/bugs.c b/arch/x86/kernel/fpu/bugs.c index aad34aafc0e0..d913047f832c 100644 --- a/arch/x86/kernel/fpu/bugs.c +++ b/arch/x86/kernel/fpu/bugs.c @@ -23,17 +23,12 @@ static double __initdata y = 3145727.0; */ void __init fpu__init_check_bugs(void) { - u32 cr0_saved; s32 fdiv_bug; /* kernel_fpu_begin/end() relies on patched alternative instructions. */ if (!boot_cpu_has(X86_FEATURE_FPU)) return; - /* We might have CR0::TS set already, clear it: */ - cr0_saved = read_cr0(); - write_cr0(cr0_saved & ~X86_CR0_TS); - kernel_fpu_begin(); /* @@ -56,8 +51,6 @@ void __init fpu__init_check_bugs(void) kernel_fpu_end(); - write_cr0(cr0_saved); - if (fdiv_bug) { set_cpu_bug(&boot_cpu_data, X86_BUG_FDIV); pr_warn("Hmm, FPU with FDIV bug\n"); diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index ebb4e95fbd74..e4e97a5355ce 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -58,27 +58,9 @@ static bool kernel_fpu_disabled(void) return this_cpu_read(in_kernel_fpu); } -/* - * Were we in an interrupt that interrupted kernel mode? - * - * On others, we can do a kernel_fpu_begin/end() pair *ONLY* if that - * pair does nothing at all: the thread must not have fpu (so - * that we don't try to save the FPU state), and TS must - * be set (so that the clts/stts pair does nothing that is - * visible in the interrupted kernel thread). - * - * Except for the eagerfpu case when we return true; in the likely case - * the thread has FPU but we are not going to set/clear TS. - */ static bool interrupted_kernel_fpu_idle(void) { - if (kernel_fpu_disabled()) - return false; - - if (use_eager_fpu()) - return true; - - return !current->thread.fpu.fpregs_active && (read_cr0() & X86_CR0_TS); + return !kernel_fpu_disabled(); } /* @@ -125,8 +107,7 @@ void __kernel_fpu_begin(void) */ copy_fpregs_to_fpstate(fpu); } else { - this_cpu_write(fpu_fpregs_owner_ctx, NULL); - __fpregs_activate_hw(); + __cpu_invalidate_fpregs_state(); } } EXPORT_SYMBOL(__kernel_fpu_begin); @@ -137,8 +118,6 @@ void __kernel_fpu_end(void) if (fpu->fpregs_active) copy_kernel_to_fpregs(&fpu->state); - else - __fpregs_deactivate_hw(); kernel_fpu_enable(); } @@ -159,35 +138,6 @@ void kernel_fpu_end(void) EXPORT_SYMBOL_GPL(kernel_fpu_end); /* - * CR0::TS save/restore functions: - */ -int irq_ts_save(void) -{ - /* - * If in process context and not atomic, we can take a spurious DNA fault. - * Otherwise, doing clts() in process context requires disabling preemption - * or some heavy lifting like kernel_fpu_begin() - */ - if (!in_atomic()) - return 0; - - if (read_cr0() & X86_CR0_TS) { - clts(); - return 1; - } - - return 0; -} -EXPORT_SYMBOL_GPL(irq_ts_save); - -void irq_ts_restore(int TS_state) -{ - if (TS_state) - stts(); -} -EXPORT_SYMBOL_GPL(irq_ts_restore); - -/* * Save the FPU state (mark it for reload if necessary): * * This only ever gets called for the current task. @@ -200,10 +150,7 @@ void fpu__save(struct fpu *fpu) trace_x86_fpu_before_save(fpu); if (fpu->fpregs_active) { if (!copy_fpregs_to_fpstate(fpu)) { - if (use_eager_fpu()) - copy_kernel_to_fpregs(&fpu->state); - else - fpregs_deactivate(fpu); + copy_kernel_to_fpregs(&fpu->state); } } trace_x86_fpu_after_save(fpu); @@ -247,7 +194,6 @@ EXPORT_SYMBOL_GPL(fpstate_init); int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) { - dst_fpu->counter = 0; dst_fpu->fpregs_active = 0; dst_fpu->last_cpu = -1; @@ -260,8 +206,7 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) * Don't let 'init optimized' areas of the XSAVE area * leak into the child task: */ - if (use_eager_fpu()) - memset(&dst_fpu->state.xsave, 0, fpu_kernel_xstate_size); + memset(&dst_fpu->state.xsave, 0, fpu_kernel_xstate_size); /* * Save current FPU registers directly into the child @@ -283,10 +228,7 @@ int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) memcpy(&src_fpu->state, &dst_fpu->state, fpu_kernel_xstate_size); - if (use_eager_fpu()) - copy_kernel_to_fpregs(&src_fpu->state); - else - fpregs_deactivate(src_fpu); + copy_kernel_to_fpregs(&src_fpu->state); } preempt_enable(); @@ -366,7 +308,7 @@ void fpu__activate_fpstate_write(struct fpu *fpu) if (fpu->fpstate_active) { /* Invalidate any lazy state: */ - fpu->last_cpu = -1; + __fpu_invalidate_fpregs_state(fpu); } else { fpstate_init(&fpu->state); trace_x86_fpu_init_state(fpu); @@ -409,7 +351,7 @@ void fpu__current_fpstate_write_begin(void) * ensures we will not be lazy and skip a XRSTOR in the * future. */ - fpu->last_cpu = -1; + __fpu_invalidate_fpregs_state(fpu); } /* @@ -459,7 +401,6 @@ void fpu__restore(struct fpu *fpu) trace_x86_fpu_before_restore(fpu); fpregs_activate(fpu); copy_kernel_to_fpregs(&fpu->state); - fpu->counter++; trace_x86_fpu_after_restore(fpu); kernel_fpu_enable(); } @@ -477,7 +418,6 @@ EXPORT_SYMBOL_GPL(fpu__restore); void fpu__drop(struct fpu *fpu) { preempt_disable(); - fpu->counter = 0; if (fpu->fpregs_active) { /* Ignore delayed exceptions from user space */ diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index 2f2b8c7ccb85..60dece392b3a 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -10,18 +10,6 @@ #include <linux/init.h> /* - * Initialize the TS bit in CR0 according to the style of context-switches - * we are using: - */ -static void fpu__init_cpu_ctx_switch(void) -{ - if (!boot_cpu_has(X86_FEATURE_EAGER_FPU)) - stts(); - else - clts(); -} - -/* * Initialize the registers found in all CPUs, CR0 and CR4: */ static void fpu__init_cpu_generic(void) @@ -58,7 +46,6 @@ void fpu__init_cpu(void) { fpu__init_cpu_generic(); fpu__init_cpu_xstate(); - fpu__init_cpu_ctx_switch(); } /* @@ -233,82 +220,16 @@ static void __init fpu__init_system_xstate_size_legacy(void) } /* - * FPU context switching strategies: - * - * Against popular belief, we don't do lazy FPU saves, due to the - * task migration complications it brings on SMP - we only do - * lazy FPU restores. - * - * 'lazy' is the traditional strategy, which is based on setting - * CR0::TS to 1 during context-switch (instead of doing a full - * restore of the FPU state), which causes the first FPU instruction - * after the context switch (whenever it is executed) to fault - at - * which point we lazily restore the FPU state into FPU registers. - * - * Tasks are of course under no obligation to execute FPU instructions, - * so it can easily happen that another context-switch occurs without - * a single FPU instruction being executed. If we eventually switch - * back to the original task (that still owns the FPU) then we have - * not only saved the restores along the way, but we also have the - * FPU ready to be used for the original task. - * - * 'lazy' is deprecated because it's almost never a performance win - * and it's much more complicated than 'eager'. - * - * 'eager' switching is by default on all CPUs, there we switch the FPU - * state during every context switch, regardless of whether the task - * has used FPU instructions in that time slice or not. This is done - * because modern FPU context saving instructions are able to optimize - * state saving and restoration in hardware: they can detect both - * unused and untouched FPU state and optimize accordingly. - * - * [ Note that even in 'lazy' mode we might optimize context switches - * to use 'eager' restores, if we detect that a task is using the FPU - * frequently. See the fpu->counter logic in fpu/internal.h for that. ] - */ -static enum { ENABLE, DISABLE } eagerfpu = ENABLE; - -/* * Find supported xfeatures based on cpu features and command-line input. * This must be called after fpu__init_parse_early_param() is called and * xfeatures_mask is enumerated. */ u64 __init fpu__get_supported_xfeatures_mask(void) { - /* Support all xfeatures known to us */ - if (eagerfpu != DISABLE) - return XCNTXT_MASK; - - /* Warning of xfeatures being disabled for no eagerfpu mode */ - if (xfeatures_mask & XFEATURE_MASK_EAGER) { - pr_err("x86/fpu: eagerfpu switching disabled, disabling the following xstate features: 0x%llx.\n", - xfeatures_mask & XFEATURE_MASK_EAGER); - } - - /* Return a mask that masks out all features requiring eagerfpu mode */ - return ~XFEATURE_MASK_EAGER; + return XCNTXT_MASK; } -/* - * Disable features dependent on eagerfpu. - */ -static void __init fpu__clear_eager_fpu_features(void) -{ - setup_clear_cpu_cap(X86_FEATURE_MPX); -} - -/* - * Pick the FPU context switching strategy: - * - * When eagerfpu is AUTO or ENABLE, we ensure it is ENABLE if either of - * the following is true: - * - * (1) the cpu has xsaveopt, as it has the optimization and doing eager - * FPU switching has a relatively low cost compared to a plain xsave; - * (2) the cpu has xsave features (e.g. MPX) that depend on eager FPU - * switching. Should the kernel boot with noxsaveopt, we support MPX - * with eager FPU switching at a higher cost. - */ +/* Legacy code to initialize eager fpu mode. */ static void __init fpu__init_system_ctx_switch(void) { static bool on_boot_cpu __initdata = 1; @@ -317,17 +238,6 @@ static void __init fpu__init_system_ctx_switch(void) on_boot_cpu = 0; WARN_ON_FPU(current->thread.fpu.fpstate_active); - - if (boot_cpu_has(X86_FEATURE_XSAVEOPT) && eagerfpu != DISABLE) - eagerfpu = ENABLE; - - if (xfeatures_mask & XFEATURE_MASK_EAGER) - eagerfpu = ENABLE; - - if (eagerfpu == ENABLE) - setup_force_cpu_cap(X86_FEATURE_EAGER_FPU); - - printk(KERN_INFO "x86/fpu: Using '%s' FPU context switches.\n", eagerfpu == ENABLE ? "eager" : "lazy"); } /* @@ -336,11 +246,6 @@ static void __init fpu__init_system_ctx_switch(void) */ static void __init fpu__init_parse_early_param(void) { - if (cmdline_find_option_bool(boot_command_line, "eagerfpu=off")) { - eagerfpu = DISABLE; - fpu__clear_eager_fpu_features(); - } - if (cmdline_find_option_bool(boot_command_line, "no387")) setup_clear_cpu_cap(X86_FEATURE_FPU); @@ -375,14 +280,6 @@ void __init fpu__init_system(struct cpuinfo_x86 *c) */ fpu__init_cpu(); - /* - * But don't leave CR0::TS set yet, as some of the FPU setup - * methods depend on being able to execute FPU instructions - * that will fault on a set TS, such as the FXSAVE in - * fpu__init_system_mxcsr(). - */ - clts(); - fpu__init_system_generic(); fpu__init_system_xstate_size_legacy(); fpu__init_system_xstate(); diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index a184c210efba..83c23c230b4c 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -340,11 +340,9 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) } fpu->fpstate_active = 1; - if (use_eager_fpu()) { - preempt_disable(); - fpu__restore(fpu); - preempt_enable(); - } + preempt_disable(); + fpu__restore(fpu); + preempt_enable(); return err; } else { diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index ce47452879fd..1d7770447b3e 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -892,15 +892,6 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, */ if (!boot_cpu_has(X86_FEATURE_OSPKE)) return -EINVAL; - /* - * For most XSAVE components, this would be an arduous task: - * brining fpstate up to date with fpregs, updating fpstate, - * then re-populating fpregs. But, for components that are - * never lazily managed, we can just access the fpregs - * directly. PKRU is never managed lazily, so we can just - * manipulate it directly. Make sure it stays that way. - */ - WARN_ON_ONCE(!use_eager_fpu()); /* Set the bits we need in PKRU: */ if (init_val & PKEY_DISABLE_ACCESS) diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index bbf3d5933eaa..a1bfba0f7234 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -328,7 +328,6 @@ __visible struct pv_cpu_ops pv_cpu_ops = { .cpuid = native_cpuid, .get_debugreg = native_get_debugreg, .set_debugreg = native_set_debugreg, - .clts = native_clts, .read_cr0 = native_read_cr0, .write_cr0 = native_write_cr0, .read_cr4 = native_read_cr4, diff --git a/arch/x86/kernel/paravirt_patch_32.c b/arch/x86/kernel/paravirt_patch_32.c index 33cdec221f3d..d33ef165b1f8 100644 --- a/arch/x86/kernel/paravirt_patch_32.c +++ b/arch/x86/kernel/paravirt_patch_32.c @@ -8,7 +8,6 @@ DEF_NATIVE(pv_cpu_ops, iret, "iret"); DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax"); DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3"); DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax"); -DEF_NATIVE(pv_cpu_ops, clts, "clts"); #if defined(CONFIG_PARAVIRT_SPINLOCKS) DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%eax)"); @@ -50,7 +49,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf, PATCH_SITE(pv_mmu_ops, read_cr2); PATCH_SITE(pv_mmu_ops, read_cr3); PATCH_SITE(pv_mmu_ops, write_cr3); - PATCH_SITE(pv_cpu_ops, clts); #if defined(CONFIG_PARAVIRT_SPINLOCKS) case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock): if (pv_is_native_spin_unlock()) { diff --git a/arch/x86/kernel/paravirt_patch_64.c b/arch/x86/kernel/paravirt_patch_64.c index b0fceff502b3..f4fcf26c9fce 100644 --- a/arch/x86/kernel/paravirt_patch_64.c +++ b/arch/x86/kernel/paravirt_patch_64.c @@ -10,7 +10,6 @@ DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax"); DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax"); DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3"); DEF_NATIVE(pv_mmu_ops, flush_tlb_single, "invlpg (%rdi)"); -DEF_NATIVE(pv_cpu_ops, clts, "clts"); DEF_NATIVE(pv_cpu_ops, wbinvd, "wbinvd"); DEF_NATIVE(pv_cpu_ops, usergs_sysret64, "swapgs; sysretq"); @@ -60,7 +59,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf, PATCH_SITE(pv_mmu_ops, read_cr2); PATCH_SITE(pv_mmu_ops, read_cr3); PATCH_SITE(pv_mmu_ops, write_cr3); - PATCH_SITE(pv_cpu_ops, clts); PATCH_SITE(pv_mmu_ops, flush_tlb_single); PATCH_SITE(pv_cpu_ops, wbinvd); #if defined(CONFIG_PARAVIRT_SPINLOCKS) diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c index e3223bc78cb6..f854404be1c6 100644 --- a/arch/x86/kernel/process_32.c +++ b/arch/x86/kernel/process_32.c @@ -231,11 +231,10 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) struct fpu *next_fpu = &next->fpu; int cpu = smp_processor_id(); struct tss_struct *tss = &per_cpu(cpu_tss, cpu); - fpu_switch_t fpu_switch; /* never put a printk in __switch_to... printk() calls wake_up*() indirectly */ - fpu_switch = switch_fpu_prepare(prev_fpu, next_fpu, cpu); + switch_fpu_prepare(prev_fpu, cpu); /* * Save away %gs. No need to save %fs, as it was saved on the @@ -294,7 +293,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) if (prev->gs | next->gs) lazy_load_gs(next->gs); - switch_fpu_finish(next_fpu, fpu_switch); + switch_fpu_finish(next_fpu, cpu); this_cpu_write(current_task, next_p); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index c99f1ca35eb5..6c1b43eab80c 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -270,9 +270,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) int cpu = smp_processor_id(); struct tss_struct *tss = &per_cpu(cpu_tss, cpu); unsigned prev_fsindex, prev_gsindex; - fpu_switch_t fpu_switch; - fpu_switch = switch_fpu_prepare(prev_fpu, next_fpu, cpu); + switch_fpu_prepare(prev_fpu, cpu); /* We must save %fs and %gs before load_TLS() because * %fs and %gs may be cleared by load_TLS(). @@ -422,7 +421,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) prev->gsbase = 0; prev->gsindex = prev_gsindex; - switch_fpu_finish(next_fpu, fpu_switch); + switch_fpu_finish(next_fpu, cpu); /* * Switch the PDA and FPU contexts. diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index f084a24c2c0f..2a501abe5000 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1132,7 +1132,7 @@ int native_cpu_up(unsigned int cpu, struct task_struct *tidle) return err; /* the FPU context is blank, nobody can own it */ - __cpu_disable_lazy_restore(cpu); + per_cpu(fpu_fpregs_owner_ctx, cpu) = NULL; common_cpu_up(cpu, tidle); diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index bd4e3d4d3625..bf0c6d049080 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -853,6 +853,8 @@ do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) dotraplinkage void do_device_not_available(struct pt_regs *regs, long error_code) { + unsigned long cr0; + RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); #ifdef CONFIG_MATH_EMULATION @@ -866,10 +868,20 @@ do_device_not_available(struct pt_regs *regs, long error_code) return; } #endif - fpu__restore(¤t->thread.fpu); /* interrupts still off */ -#ifdef CONFIG_X86_32 - cond_local_irq_enable(regs); -#endif + + /* This should not happen. */ + cr0 = read_cr0(); + if (WARN(cr0 & X86_CR0_TS, "CR0.TS was set")) { + /* Try to fix it up and carry on. */ + write_cr0(cr0 & ~X86_CR0_TS); + } else { + /* + * Something terrible happened, and we're better off trying + * to kill the task than getting stuck in a never-ending + * loop of #NM faults. + */ + die("unexpected #NM exception", regs, error_code); + } } NOKPROBE_SYMBOL(do_device_not_available); diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index afa7bbb596cd..0aefb626fa8f 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -16,7 +16,6 @@ #include <linux/export.h> #include <linux/vmalloc.h> #include <linux/uaccess.h> -#include <asm/fpu/internal.h> /* For use_eager_fpu. Ugh! */ #include <asm/user.h> #include <asm/fpu/xstate.h> #include "cpuid.h" @@ -114,8 +113,7 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) best->ebx = xstate_required_size(vcpu->arch.xcr0, true); - if (use_eager_fpu()) - kvm_x86_ops->fpu_activate(vcpu); + kvm_x86_ops->fpu_activate(vcpu); /* * The existing code assumes virtual address is 48-bit in the canonical diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 5382b82462fc..3980da515fd0 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2145,12 +2145,6 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx) #endif if (vmx->host_state.msr_host_bndcfgs) wrmsrl(MSR_IA32_BNDCFGS, vmx->host_state.msr_host_bndcfgs); - /* - * If the FPU is not active (through the host task or - * the guest vcpu), then restore the cr0.TS bit. - */ - if (!fpregs_active() && !vmx->vcpu.guest_fpu_loaded) - stts(); load_gdt(this_cpu_ptr(&host_gdt)); } @@ -4845,9 +4839,11 @@ static void vmx_set_constant_host_state(struct vcpu_vmx *vmx) u32 low32, high32; unsigned long tmpl; struct desc_ptr dt; - unsigned long cr4; + unsigned long cr0, cr4; - vmcs_writel(HOST_CR0, read_cr0() & ~X86_CR0_TS); /* 22.2.3 */ + cr0 = read_cr0(); + WARN_ON(cr0 & X86_CR0_TS); + vmcs_writel(HOST_CR0, cr0); /* 22.2.3 */ vmcs_writel(HOST_CR3, read_cr3()); /* 22.2.3 FIXME: shadow tables */ /* Save the most likely value for this task's CR4 in the VMCS. */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 59c2d6f1b131..6f5f465fdb6b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5097,11 +5097,6 @@ static void emulator_get_fpu(struct x86_emulate_ctxt *ctxt) { preempt_disable(); kvm_load_guest_fpu(emul_to_vcpu(ctxt)); - /* - * CR0.TS may reference the host fpu state, not the guest fpu state, - * so it may be clear at this point. - */ - clts(); } static void emulator_put_fpu(struct x86_emulate_ctxt *ctxt) @@ -7423,25 +7418,13 @@ void kvm_load_guest_fpu(struct kvm_vcpu *vcpu) void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) { - if (!vcpu->guest_fpu_loaded) { - vcpu->fpu_counter = 0; + if (!vcpu->guest_fpu_loaded) return; - } vcpu->guest_fpu_loaded = 0; copy_fpregs_to_fpstate(&vcpu->arch.guest_fpu); __kernel_fpu_end(); ++vcpu->stat.fpu_reload; - /* - * If using eager FPU mode, or if the guest is a frequent user - * of the FPU, just leave the FPU active for next time. - * Every 255 times fpu_counter rolls over to 0; a guest that uses - * the FPU in bursts will revert to loading it on demand. - */ - if (!use_eager_fpu()) { - if (++vcpu->fpu_counter < 5) - kvm_make_request(KVM_REQ_DEACTIVATE_FPU, vcpu); - } trace_kvm_fpu(0); } diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 25da5bc8d83d..4ca0d78adcf0 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -497,38 +497,24 @@ static void lguest_cpuid(unsigned int *ax, unsigned int *bx, * a whole series of functions like read_cr0() and write_cr0(). * * We start with cr0. cr0 allows you to turn on and off all kinds of basic - * features, but Linux only really cares about one: the horrifically-named Task - * Switched (TS) bit at bit 3 (ie. 8) + * features, but the only cr0 bit that Linux ever used at runtime was the + * horrifically-named Task Switched (TS) bit at bit 3 (ie. 8) * * What does the TS bit do? Well, it causes the CPU to trap (interrupt 7) if * the floating point unit is used. Which allows us to restore FPU state - * lazily after a task switch, and Linux uses that gratefully, but wouldn't a - * name like "FPUTRAP bit" be a little less cryptic? + * lazily after a task switch if we wanted to, but wouldn't a name like + * "FPUTRAP bit" be a little less cryptic? * - * We store cr0 locally because the Host never changes it. The Guest sometimes - * wants to read it and we'd prefer not to bother the Host unnecessarily. + * Fortunately, Linux keeps it simple and doesn't use TS, so we can ignore + * cr0. */ -static unsigned long current_cr0; static void lguest_write_cr0(unsigned long val) { - lazy_hcall1(LHCALL_TS, val & X86_CR0_TS); - current_cr0 = val; } static unsigned long lguest_read_cr0(void) { - return current_cr0; -} - -/* - * Intel provided a special instruction to clear the TS bit for people too cool - * to use write_cr0() to do it. This "clts" instruction is faster, because all - * the vowels have been optimized out. - */ -static void lguest_clts(void) -{ - lazy_hcall1(LHCALL_TS, 0); - current_cr0 &= ~X86_CR0_TS; + return 0; } /* @@ -1432,7 +1418,6 @@ __init void lguest_init(void) pv_cpu_ops.load_tls = lguest_load_tls; pv_cpu_ops.get_debugreg = lguest_get_debugreg; pv_cpu_ops.set_debugreg = lguest_set_debugreg; - pv_cpu_ops.clts = lguest_clts; pv_cpu_ops.read_cr0 = lguest_read_cr0; pv_cpu_ops.write_cr0 = lguest_write_cr0; pv_cpu_ops.read_cr4 = lguest_read_cr4; diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index f88ce0e5efd9..2dab69a706ec 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -141,8 +141,7 @@ u32 init_pkru_value = PKRU_AD_KEY( 1) | PKRU_AD_KEY( 2) | PKRU_AD_KEY( 3) | * Called from the FPU code when creating a fresh set of FPU * registers. This is called from a very specific context where * we know the FPU regstiers are safe for use and we can use PKRU - * directly. The fact that PKRU is only available when we are - * using eagerfpu mode makes this possible. + * directly. */ void copy_init_pkru_to_fpregs(void) { diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index bdd855685403..ced7027b3fbc 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -980,17 +980,6 @@ static void xen_io_delay(void) { } -static void xen_clts(void) -{ - struct multicall_space mcs; - - mcs = xen_mc_entry(0); - - MULTI_fpu_taskswitch(mcs.mc, 0); - - xen_mc_issue(PARAVIRT_LAZY_CPU); -} - static DEFINE_PER_CPU(unsigned long, xen_cr0_value); static unsigned long xen_read_cr0(void) @@ -1233,8 +1222,6 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = { .set_debugreg = xen_set_debugreg, .get_debugreg = xen_get_debugreg, - .clts = xen_clts, - .read_cr0 = xen_read_cr0, .write_cr0 = xen_write_cr0, diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c index 44ce80606944..d1f5bb534e0e 100644 --- a/drivers/char/hw_random/via-rng.c +++ b/drivers/char/hw_random/via-rng.c @@ -70,21 +70,17 @@ enum { * until we have 4 bytes, thus returning a u32 at a time, * instead of the current u8-at-a-time. * - * Padlock instructions can generate a spurious DNA fault, so - * we have to call them in the context of irq_ts_save/restore() + * Padlock instructions can generate a spurious DNA fault, but the + * kernel doesn't use CR0.TS, so this doesn't matter. */ static inline u32 xstore(u32 *addr, u32 edx_in) { u32 eax_out; - int ts_state; - - ts_state = irq_ts_save(); asm(".byte 0x0F,0xA7,0xC0 /* xstore %%edi (addr=%0) */" : "=m" (*addr), "=a" (eax_out), "+d" (edx_in), "+D" (addr)); - irq_ts_restore(ts_state); return eax_out; } diff --git a/drivers/crypto/padlock-aes.c b/drivers/crypto/padlock-aes.c index 441e86b23571..b3869748cc6b 100644 --- a/drivers/crypto/padlock-aes.c +++ b/drivers/crypto/padlock-aes.c @@ -183,8 +183,8 @@ static inline void padlock_store_cword(struct cword *cword) /* * While the padlock instructions don't use FP/SSE registers, they - * generate a spurious DNA fault when cr0.ts is '1'. These instructions - * should be used only inside the irq_ts_save/restore() context + * generate a spurious DNA fault when CR0.TS is '1'. Fortunately, + * the kernel doesn't use CR0.TS. */ static inline void rep_xcrypt_ecb(const u8 *input, u8 *output, void *key, @@ -298,24 +298,18 @@ static inline u8 *padlock_xcrypt_cbc(const u8 *input, u8 *output, void *key, static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) { struct aes_ctx *ctx = aes_ctx(tfm); - int ts_state; padlock_reset_key(&ctx->cword.encrypt); - ts_state = irq_ts_save(); ecb_crypt(in, out, ctx->E, &ctx->cword.encrypt, 1); - irq_ts_restore(ts_state); padlock_store_cword(&ctx->cword.encrypt); } static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) { struct aes_ctx *ctx = aes_ctx(tfm); - int ts_state; padlock_reset_key(&ctx->cword.encrypt); - ts_state = irq_ts_save(); ecb_crypt(in, out, ctx->D, &ctx->cword.decrypt, 1); - irq_ts_restore(ts_state); padlock_store_cword(&ctx->cword.encrypt); } @@ -346,14 +340,12 @@ static int ecb_aes_encrypt(struct blkcipher_desc *desc, struct aes_ctx *ctx = blk_aes_ctx(desc->tfm); struct blkcipher_walk walk; int err; - int ts_state; padlock_reset_key(&ctx->cword.encrypt); blkcipher_walk_init(&walk, dst, src, nbytes); err = blkcipher_walk_virt(desc, &walk); - ts_state = irq_ts_save(); while ((nbytes = walk.nbytes)) { padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr, ctx->E, &ctx->cword.encrypt, @@ -361,7 +353,6 @@ static int ecb_aes_encrypt(struct blkcipher_desc *desc, nbytes &= AES_BLOCK_SIZE - 1; err = blkcipher_walk_done(desc, &walk, nbytes); } - irq_ts_restore(ts_state); padlock_store_cword(&ctx->cword.encrypt); @@ -375,14 +366,12 @@ static int ecb_aes_decrypt(struct blkcipher_desc *desc, struct aes_ctx *ctx = blk_aes_ctx(desc->tfm); struct blkcipher_walk walk; int err; - int ts_state; padlock_reset_key(&ctx->cword.decrypt); blkcipher_walk_init(&walk, dst, src, nbytes); err = blkcipher_walk_virt(desc, &walk); - ts_state = irq_ts_save(); while ((nbytes = walk.nbytes)) { padlock_xcrypt_ecb(walk.src.virt.addr, walk.dst.virt.addr, ctx->D, &ctx->cword.decrypt, @@ -390,7 +379,6 @@ static int ecb_aes_decrypt(struct blkcipher_desc *desc, nbytes &= AES_BLOCK_SIZE - 1; err = blkcipher_walk_done(desc, &walk, nbytes); } - irq_ts_restore(ts_state); padlock_store_cword(&ctx->cword.encrypt); @@ -425,14 +413,12 @@ static int cbc_aes_encrypt(struct blkcipher_desc *desc, struct aes_ctx *ctx = blk_aes_ctx(desc->tfm); struct blkcipher_walk walk; int err; - int ts_state; padlock_reset_key(&ctx->cword.encrypt); blkcipher_walk_init(&walk, dst, src, nbytes); err = blkcipher_walk_virt(desc, &walk); - ts_state = irq_ts_save(); while ((nbytes = walk.nbytes)) { u8 *iv = padlock_xcrypt_cbc(walk.src.virt.addr, walk.dst.virt.addr, ctx->E, @@ -442,7 +428,6 @@ static int cbc_aes_encrypt(struct blkcipher_desc *desc, nbytes &= AES_BLOCK_SIZE - 1; err = blkcipher_walk_done(desc, &walk, nbytes); } - irq_ts_restore(ts_state); padlock_store_cword(&ctx->cword.decrypt); @@ -456,14 +441,12 @@ static int cbc_aes_decrypt(struct blkcipher_desc *desc, struct aes_ctx *ctx = blk_aes_ctx(desc->tfm); struct blkcipher_walk walk; int err; - int ts_state; padlock_reset_key(&ctx->cword.encrypt); blkcipher_walk_init(&walk, dst, src, nbytes); err = blkcipher_walk_virt(desc, &walk); - ts_state = irq_ts_save(); while ((nbytes = walk.nbytes)) { padlock_xcrypt_cbc(walk.src.virt.addr, walk.dst.virt.addr, ctx->D, walk.iv, &ctx->cword.decrypt, @@ -472,8 +455,6 @@ static int cbc_aes_decrypt(struct blkcipher_desc *desc, err = blkcipher_walk_done(desc, &walk, nbytes); } - irq_ts_restore(ts_state); - padlock_store_cword(&ctx->cword.encrypt); return err; diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c index 8c5f90647b7a..bc72d20c32c3 100644 --- a/drivers/crypto/padlock-sha.c +++ b/drivers/crypto/padlock-sha.c @@ -89,7 +89,6 @@ static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in, struct sha1_state state; unsigned int space; unsigned int leftover; - int ts_state; int err; dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; @@ -120,14 +119,11 @@ static int padlock_sha1_finup(struct shash_desc *desc, const u8 *in, memcpy(result, &state.state, SHA1_DIGEST_SIZE); - /* prevent taking the spurious DNA fault with padlock. */ - ts_state = irq_ts_save(); asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */ : \ : "c"((unsigned long)state.count + count), \ "a"((unsigned long)state.count), \ "S"(in), "D"(result)); - irq_ts_restore(ts_state); padlock_output_block((uint32_t *)result, (uint32_t *)out, 5); @@ -155,7 +151,6 @@ static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in, struct sha256_state state; unsigned int space; unsigned int leftover; - int ts_state; int err; dctx->fallback.flags = desc->flags & CRYPTO_TFM_REQ_MAY_SLEEP; @@ -186,14 +181,11 @@ static int padlock_sha256_finup(struct shash_desc *desc, const u8 *in, memcpy(result, &state.state, SHA256_DIGEST_SIZE); - /* prevent taking the spurious DNA fault with padlock. */ - ts_state = irq_ts_save(); asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */ : \ : "c"((unsigned long)state.count + count), \ "a"((unsigned long)state.count), \ "S"(in), "D"(result)); - irq_ts_restore(ts_state); padlock_output_block((uint32_t *)result, (uint32_t *)out, 8); @@ -312,7 +304,6 @@ static int padlock_sha1_update_nano(struct shash_desc *desc, u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__ ((aligned(STACK_ALIGN))); u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT); - int ts_state; partial = sctx->count & 0x3f; sctx->count += len; @@ -328,23 +319,19 @@ static int padlock_sha1_update_nano(struct shash_desc *desc, memcpy(sctx->buffer + partial, data, done + SHA1_BLOCK_SIZE); src = sctx->buffer; - ts_state = irq_ts_save(); asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" : "+S"(src), "+D"(dst) \ : "a"((long)-1), "c"((unsigned long)1)); - irq_ts_restore(ts_state); done += SHA1_BLOCK_SIZE; src = data + done; } /* Process the left bytes from the input data */ if (len - done >= SHA1_BLOCK_SIZE) { - ts_state = irq_ts_save(); asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" : "+S"(src), "+D"(dst) : "a"((long)-1), "c"((unsigned long)((len - done) / SHA1_BLOCK_SIZE))); - irq_ts_restore(ts_state); done += ((len - done) - (len - done) % SHA1_BLOCK_SIZE); src = data + done; } @@ -401,7 +388,6 @@ static int padlock_sha256_update_nano(struct shash_desc *desc, const u8 *data, u8 buf[128 + PADLOCK_ALIGNMENT - STACK_ALIGN] __attribute__ ((aligned(STACK_ALIGN))); u8 *dst = PTR_ALIGN(&buf[0], PADLOCK_ALIGNMENT); - int ts_state; partial = sctx->count & 0x3f; sctx->count += len; @@ -417,23 +403,19 @@ static int padlock_sha256_update_nano(struct shash_desc *desc, const u8 *data, memcpy(sctx->buf + partial, data, done + SHA256_BLOCK_SIZE); src = sctx->buf; - ts_state = irq_ts_save(); asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" : "+S"(src), "+D"(dst) : "a"((long)-1), "c"((unsigned long)1)); - irq_ts_restore(ts_state); done += SHA256_BLOCK_SIZE; src = data + done; } /* Process the left bytes from input data*/ if (len - done >= SHA256_BLOCK_SIZE) { - ts_state = irq_ts_save(); asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" : "+S"(src), "+D"(dst) : "a"((long)-1), "c"((unsigned long)((len - done) / 64))); - irq_ts_restore(ts_state); done += ((len - done) - (len - done) % 64); src = data + done; } diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c index 19a32280731d..601f81c04873 100644 --- a/drivers/lguest/hypercalls.c +++ b/drivers/lguest/hypercalls.c @@ -109,10 +109,6 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args) case LHCALL_SET_CLOCKEVENT: guest_set_clockevent(cpu, args->arg1); break; - case LHCALL_TS: - /* This sets the TS flag, as we saw used in run_guest(). */ - cpu->ts = args->arg1; - break; case LHCALL_HALT: /* Similarly, this sets the halted flag for run_guest(). */ cpu->halted = 1; diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h index 69b3814afd2f..2356a2318034 100644 --- a/drivers/lguest/lg.h +++ b/drivers/lguest/lg.h @@ -43,7 +43,6 @@ struct lg_cpu { struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */ u32 cr2; - int ts; u32 esp1; u16 ss1; diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 6e9042e3d2a9..743253fc638f 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -247,14 +247,6 @@ unsigned long *lguest_arch_regptr(struct lg_cpu *cpu, size_t reg_off, bool any) void lguest_arch_run_guest(struct lg_cpu *cpu) { /* - * Remember the awfully-named TS bit? If the Guest has asked to set it - * we set it now, so we can trap and pass that trap to the Guest if it - * uses the FPU. - */ - if (cpu->ts && fpregs_active()) - stts(); - - /* * SYSENTER is an optimized way of doing system calls. We can't allow * it because it always jumps to privilege level 0. A normal Guest * won't try it because we don't advertise it in CPUID, but a malicious @@ -282,10 +274,6 @@ void lguest_arch_run_guest(struct lg_cpu *cpu) if (boot_cpu_has(X86_FEATURE_SEP)) wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0); - /* Clear the host TS bit if it was set above. */ - if (cpu->ts && fpregs_active()) - clts(); - /* * If the Guest page faulted, then the cr2 register will tell us the * bad virtual address. We have to grab this now, because once we @@ -421,12 +409,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu) kill_guest(cpu, "Writing cr2"); break; case 7: /* We've intercepted a Device Not Available fault. */ - /* - * If the Guest doesn't want to know, we already restored the - * Floating Point Unit, so we just continue without telling it. - */ - if (!cpu->ts) - return; + /* No special handling is needed here. */ break; case 32 ... 255: /* This might be a syscall. */ diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 6f0023797b33..81ba3ba641ba 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -224,7 +224,6 @@ struct kvm_vcpu { int fpu_active; int guest_fpu_loaded, guest_xcr0_loaded; - unsigned char fpu_counter; struct swait_queue_head wq; struct pid *pid; int sigset_active; diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h index a39629206864..cddd5d06e1cb 100644 --- a/tools/arch/x86/include/asm/cpufeatures.h +++ b/tools/arch/x86/include/asm/cpufeatures.h @@ -104,7 +104,6 @@ #define X86_FEATURE_EXTD_APICID ( 3*32+26) /* has extended APICID (8 bits) */ #define X86_FEATURE_AMD_DCM ( 3*32+27) /* multi-node processor */ #define X86_FEATURE_APERFMPERF ( 3*32+28) /* APERFMPERF */ -#define X86_FEATURE_EAGER_FPU ( 3*32+29) /* "eagerfpu" Non lazy FPU restore */ #define X86_FEATURE_NONSTOP_TSC_S3 ( 3*32+30) /* TSC doesn't stop in S3 state */ /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */ |