diff options
Diffstat (limited to 'arch/x86/include/asm/fpu')
| -rw-r--r-- | arch/x86/include/asm/fpu/api.h | 37 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/regset.h | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/sched.h | 43 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/signal.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/types.h | 104 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/xcr.h | 4 | ||||
| -rw-r--r-- | arch/x86/include/asm/fpu/xstate.h | 14 |
7 files changed, 137 insertions, 74 deletions
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 503a577814b2..cd6f194a912b 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -16,10 +16,9 @@ /* * Use kernel_fpu_begin/end() if you intend to use FPU in kernel context. It - * disables preemption so be careful if you intend to use it for long periods - * of time. - * If you intend to use the FPU in irq/softirq you need to check first with - * irq_fpu_usable() if it is possible. + * disables preemption and softirq processing, so be careful if you intend to + * use it for long periods of time. Kernel-mode FPU cannot be used in all + * contexts -- see irq_fpu_usable() for details. */ /* Kernel FPU states to initialize in kernel_fpu_begin_mask() */ @@ -50,10 +49,10 @@ static inline void kernel_fpu_begin(void) } /* - * Use fpregs_lock() while editing CPU's FPU registers or fpu->fpstate. - * A context switch will (and softirq might) save CPU's FPU registers to - * fpu->fpstate.regs and set TIF_NEED_FPU_LOAD leaving CPU's FPU registers in - * a random state. + * Use fpregs_lock() while editing CPU's FPU registers or fpu->fpstate, or while + * using the FPU in kernel mode. A context switch will (and softirq might) save + * CPU's FPU registers to fpu->fpstate.regs and set TIF_NEED_FPU_LOAD leaving + * CPU's FPU registers in a random state. * * local_bh_disable() protects against both preemption and soft interrupts * on !RT kernels. @@ -63,8 +62,6 @@ static inline void kernel_fpu_begin(void) * preemptible. Disabling preemption is the right choice here as bottom * half processing is always in thread context on RT kernels so it * implicitly prevents bottom half processing as well. - * - * Disabling preemption also serializes against kernel_fpu_begin(). */ static inline void fpregs_lock(void) { @@ -82,6 +79,15 @@ static inline void fpregs_unlock(void) preempt_enable(); } +/* + * FPU state gets lazily restored before returning to userspace. So when in the + * kernel, the valid FPU state may be kept in the buffer. This function will force + * restore all the fpu state to the registers early if needed, and lock them from + * being automatically saved/restored. Then FPU state can be modified safely in the + * registers, before unlocking with fpregs_unlock(). + */ +void fpregs_lock_and_load(void); + #ifdef CONFIG_X86_DEBUG_FPU extern void fpregs_assert_state_consistent(void); #else @@ -109,7 +115,7 @@ extern void fpu_reset_from_exception_fixup(void); /* Boot, hotplug and resume */ extern void fpu__init_cpu(void); -extern void fpu__init_system(struct cpuinfo_x86 *c); +extern void fpu__init_system(void); extern void fpu__init_check_bugs(void); extern void fpu__resume_cpu(void); @@ -120,6 +126,7 @@ static inline void fpstate_init_soft(struct swregs_state *soft) {} #endif /* State tracking */ +DECLARE_PER_CPU(bool, kernel_fpu_allowed); DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx); /* Process cleanup */ @@ -130,10 +137,13 @@ static inline void fpstate_free(struct fpu *fpu) { } #endif /* fpstate-related functions which are exported to KVM */ -extern void fpstate_clear_xstate_component(struct fpstate *fps, unsigned int xfeature); +extern void fpstate_clear_xstate_component(struct fpstate *fpstate, unsigned int xfeature); extern u64 xstate_get_guest_group_perm(void); +extern void *get_xsave_addr(struct xregs_state *xsave, int xfeature_nr); + + /* KVM specific functions */ extern bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu); extern void fpu_free_guest_fpstate(struct fpu_guest *gfpu); @@ -148,7 +158,8 @@ static inline void fpu_update_guest_xfd(struct fpu_guest *guest_fpu, u64 xfd) { static inline void fpu_sync_guest_vmexit_xfd_state(void) { } #endif -extern void fpu_copy_guest_fpstate_to_uabi(struct fpu_guest *gfpu, void *buf, unsigned int size, u32 pkru); +extern void fpu_copy_guest_fpstate_to_uabi(struct fpu_guest *gfpu, void *buf, + unsigned int size, u64 xfeatures, u32 pkru); extern int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, u64 xcr0, u32 *vpkru); static inline void fpstate_set_confidential(struct fpu_guest *gfpu) diff --git a/arch/x86/include/asm/fpu/regset.h b/arch/x86/include/asm/fpu/regset.h index 4f928d6a367b..697b77e96025 100644 --- a/arch/x86/include/asm/fpu/regset.h +++ b/arch/x86/include/asm/fpu/regset.h @@ -7,11 +7,12 @@ #include <linux/regset.h> -extern user_regset_active_fn regset_fpregs_active, regset_xregset_fpregs_active; +extern user_regset_active_fn regset_fpregs_active, regset_xregset_fpregs_active, + ssp_active; extern user_regset_get2_fn fpregs_get, xfpregs_get, fpregs_soft_get, - xstateregs_get; + xstateregs_get, ssp_get; extern user_regset_set_fn fpregs_set, xfpregs_set, fpregs_soft_set, - xstateregs_set; + xstateregs_set, ssp_set; /* * xstateregs_active == regset_fpregs_active. Please refer to the comment diff --git a/arch/x86/include/asm/fpu/sched.h b/arch/x86/include/asm/fpu/sched.h index b2486b2cbc6e..89004f4ca208 100644 --- a/arch/x86/include/asm/fpu/sched.h +++ b/arch/x86/include/asm/fpu/sched.h @@ -10,36 +10,33 @@ #include <asm/trace/fpu.h> extern void save_fpregs_to_fpstate(struct fpu *fpu); -extern void fpu__drop(struct fpu *fpu); -extern int fpu_clone(struct task_struct *dst, unsigned long clone_flags, bool minimal); +extern void fpu__drop(struct task_struct *tsk); +extern int fpu_clone(struct task_struct *dst, u64 clone_flags, bool minimal, + unsigned long shstk_addr); extern void fpu_flush_thread(void); /* * FPU state switching for scheduling. * - * This is a two-stage process: + * switch_fpu() saves the old state and sets TIF_NEED_FPU_LOAD if + * TIF_NEED_FPU_LOAD is not set. 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() sets TIF_NEED_FPU_LOAD; the floating point state - * will get loaded on return to userspace, or when the kernel needs it. - * - * If TIF_NEED_FPU_LOAD is cleared then the CPU's FPU registers - * are saved in the current thread's FPU register state. - * - * If TIF_NEED_FPU_LOAD is set then CPU's FPU registers may not - * hold current()'s FPU registers. It is required to load the + * Once TIF_NEED_FPU_LOAD is set, it is required to load the * registers before returning to userland or using the content * otherwise. * * The FPU context is only stored/restored for a user task and * PF_KTHREAD is used to distinguish between kernel and user threads. */ -static inline void switch_fpu_prepare(struct fpu *old_fpu, int cpu) +static inline void switch_fpu(struct task_struct *old, int cpu) { - if (cpu_feature_enabled(X86_FEATURE_FPU) && - !(current->flags & PF_KTHREAD)) { + if (!test_tsk_thread_flag(old, TIF_NEED_FPU_LOAD) && + cpu_feature_enabled(X86_FEATURE_FPU) && + !(old->flags & (PF_KTHREAD | PF_USER_WORKER))) { + struct fpu *old_fpu = x86_task_fpu(old); + + set_tsk_thread_flag(old, TIF_NEED_FPU_LOAD); save_fpregs_to_fpstate(old_fpu); /* * The save operation preserved register state, so the @@ -47,7 +44,7 @@ static inline void switch_fpu_prepare(struct fpu *old_fpu, int cpu) * current CPU number in @old_fpu, so the next return * to user space can avoid the FPU register restore * when is returns on the same CPU and still owns the - * context. + * context. See fpregs_restore_userregs(). */ old_fpu->last_cpu = cpu; @@ -55,14 +52,4 @@ static inline void switch_fpu_prepare(struct fpu *old_fpu, int cpu) } } -/* - * Delay loading of the complete FPU state until the return to userland. - * PKRU is handled separately. - */ -static inline void switch_fpu_finish(void) -{ - if (cpu_feature_enabled(X86_FEATURE_FPU)) - set_thread_flag(TIF_NEED_FPU_LOAD); -} - #endif /* _ASM_X86_FPU_SCHED_H */ diff --git a/arch/x86/include/asm/fpu/signal.h b/arch/x86/include/asm/fpu/signal.h index 611fa41711af..eccc75bc9c4f 100644 --- a/arch/x86/include/asm/fpu/signal.h +++ b/arch/x86/include/asm/fpu/signal.h @@ -29,7 +29,7 @@ fpu__alloc_mathframe(unsigned long sp, int ia32_frame, unsigned long fpu__get_fpstate_size(void); -extern bool copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size); +extern bool copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size, u32 pkru); extern void fpu__clear_user_states(struct fpu *fpu); extern bool fpu__restore_sig(void __user *buf, int ia32_frame); diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index eb7cd1139d97..93e99d2583d6 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -2,8 +2,10 @@ /* * FPU data structures: */ -#ifndef _ASM_X86_FPU_H -#define _ASM_X86_FPU_H +#ifndef _ASM_X86_FPU_TYPES_H +#define _ASM_X86_FPU_TYPES_H + +#include <asm/page_types.h> /* * The legacy x87 FPU state format, as saved by FSAVE and @@ -115,14 +117,15 @@ enum xfeature { XFEATURE_PT_UNIMPLEMENTED_SO_FAR, XFEATURE_PKRU, XFEATURE_PASID, - XFEATURE_RSRVD_COMP_11, - XFEATURE_RSRVD_COMP_12, + XFEATURE_CET_USER, + XFEATURE_CET_KERNEL, XFEATURE_RSRVD_COMP_13, XFEATURE_RSRVD_COMP_14, XFEATURE_LBR, XFEATURE_RSRVD_COMP_16, XFEATURE_XTILE_CFG, XFEATURE_XTILE_DATA, + XFEATURE_APX, XFEATURE_MAX, }; @@ -138,9 +141,12 @@ enum xfeature { #define XFEATURE_MASK_PT (1 << XFEATURE_PT_UNIMPLEMENTED_SO_FAR) #define XFEATURE_MASK_PKRU (1 << XFEATURE_PKRU) #define XFEATURE_MASK_PASID (1 << XFEATURE_PASID) +#define XFEATURE_MASK_CET_USER (1 << XFEATURE_CET_USER) +#define XFEATURE_MASK_CET_KERNEL (1 << XFEATURE_CET_KERNEL) #define XFEATURE_MASK_LBR (1 << XFEATURE_LBR) #define XFEATURE_MASK_XTILE_CFG (1 << XFEATURE_XTILE_CFG) #define XFEATURE_MASK_XTILE_DATA (1 << XFEATURE_XTILE_DATA) +#define XFEATURE_MASK_APX (1 << XFEATURE_APX) #define XFEATURE_MASK_FPSSE (XFEATURE_MASK_FP | XFEATURE_MASK_SSE) #define XFEATURE_MASK_AVX512 (XFEATURE_MASK_OPMASK \ @@ -253,6 +259,26 @@ struct pkru_state { } __packed; /* + * State component 11 is Control-flow Enforcement user states + */ +struct cet_user_state { + /* user control-flow settings */ + u64 user_cet; + /* user shadow stack pointer */ + u64 user_ssp; +}; + +/* + * State component 12 is Control-flow Enforcement supervisor states. + * This state includes SSP pointers for privilege levels 0 through 2. + */ +struct cet_supervisor_state { + u64 pl0_ssp; + u64 pl1_ssp; + u64 pl2_ssp; +} __packed; + +/* * State component 15: Architectural LBR configuration state. * The size of Arch LBR state depends on the number of LBRs (lbr_depth). */ @@ -290,6 +316,13 @@ struct xtile_data { } __packed; /* + * State component 19: 8B extended general purpose register. + */ +struct apx_state { + u64 egpr[16]; +} __packed; + +/* * State component 10 is supervisor state used for context-switching the * PASID state. */ @@ -321,7 +354,7 @@ struct xstate_header { struct xregs_state { struct fxregs_state i387; struct xstate_header header; - u8 extended_state_area[0]; + u8 extended_state_area[]; } __attribute__ ((packed, aligned (64))); /* @@ -393,9 +426,11 @@ struct fpu_state_perm { /* * @__state_perm: * - * This bitmap indicates the permission for state components, which - * are available to a thread group. The permission prctl() sets the - * enabled state bits in thread_group_leader()->thread.fpu. + * This bitmap indicates the permission for state components + * available to a thread group, including both user and supervisor + * components and software-defined bits like FPU_GUEST_PERM_LOCKED. + * The permission prctl() sets the enabled state bits in + * thread_group_leader()->thread.fpu. * * All run time operations use the per thread information in the * currently active fpu.fpstate which contains the xfeature masks @@ -403,7 +438,7 @@ struct fpu_state_perm { * * This master permission field is only to be used when * task.fpu.fpstate based checks fail to validate whether the task - * is allowed to expand it's xfeatures set which requires to + * is allowed to expand its xfeatures set which requires to * allocate a larger sized fpstate buffer. * * Do not access this field directly. Use the provided helper @@ -511,13 +546,6 @@ struct fpu_guest { u64 xfeatures; /* - * @perm: xfeature bitmap of features which are - * permitted to be enabled for the guest - * vCPU. - */ - u64 perm; - - /* * @xfd_err: Save the guest value. */ u64 xfd_err; @@ -534,6 +562,31 @@ struct fpu_guest { }; /* + * FPU state configuration data for fpu_guest. + * Initialized at boot time. Read only after init. + */ +struct vcpu_fpu_config { + /* + * @size: + * + * The default size of the register state buffer in guest FPUs. + * Includes all supported features except independent managed + * features and features which have to be requested by user space + * before usage. + */ + unsigned int size; + + /* + * @features: + * + * The default supported features bitmap in guest FPUs. Does not + * include independent managed features and features which have to + * be requested by user space before usage. + */ + u64 features; +}; + +/* * FPU state configuration data. Initialized at boot time. Read only after init. */ struct fpu_state_config { @@ -549,8 +602,9 @@ struct fpu_state_config { * @default_size: * * The default size of the register state buffer. Includes all - * supported features except independent managed features and - * features which have to be requested by user space before usage. + * supported features except independent managed features, + * guest-only features and features which have to be requested by + * user space before usage. */ unsigned int default_size; @@ -566,8 +620,8 @@ struct fpu_state_config { * @default_features: * * The default supported features bitmap. Does not include - * independent managed features and features which have to - * be requested by user space before usage. + * independent managed features, guest-only features and features + * which have to be requested by user space before usage. */ u64 default_features; /* @@ -577,9 +631,17 @@ struct fpu_state_config { * even without XSAVE support, i.e. legacy features FP + SSE */ u64 legacy_features; + /* + * @independent_features: + * + * Features that are supported by XSAVES, but not managed as part of + * the FPU core, such as LBR + */ + u64 independent_features; }; /* FPU state configuration information */ extern struct fpu_state_config fpu_kernel_cfg, fpu_user_cfg; +extern struct vcpu_fpu_config guest_default_cfg; -#endif /* _ASM_X86_FPU_H */ +#endif /* _ASM_X86_FPU_TYPES_H */ diff --git a/arch/x86/include/asm/fpu/xcr.h b/arch/x86/include/asm/fpu/xcr.h index 9656a5bc6fea..9a710c060445 100644 --- a/arch/x86/include/asm/fpu/xcr.h +++ b/arch/x86/include/asm/fpu/xcr.h @@ -5,7 +5,7 @@ #define XCR_XFEATURE_ENABLED_MASK 0x00000000 #define XCR_XFEATURE_IN_USE_MASK 0x00000001 -static inline u64 xgetbv(u32 index) +static __always_inline u64 xgetbv(u32 index) { u32 eax, edx; @@ -27,7 +27,7 @@ static inline void xsetbv(u32 index, u64 value) * * Callers should check X86_FEATURE_XGETBV1. */ -static inline u64 xfeatures_in_use(void) +static __always_inline u64 xfeatures_in_use(void) { return xgetbv(XCR_XFEATURE_IN_USE_MASK); } diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index cd3dd170e23a..7a7dc9d56027 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -12,10 +12,6 @@ /* Bit 63 of XCR0 is reserved for future expansion */ #define XFEATURE_MASK_EXTEND (~(XFEATURE_MASK_FPSSE | (1ULL << 63))) -#define XSTATE_CPUID 0x0000000d - -#define TILE_CPUID 0x0000001d - #define FXSAVE_SIZE 512 #define XSAVE_HDR_SIZE 64 @@ -36,7 +32,8 @@ XFEATURE_MASK_PKRU | \ XFEATURE_MASK_BNDREGS | \ XFEATURE_MASK_BNDCSR | \ - XFEATURE_MASK_XTILE) + XFEATURE_MASK_XTILE | \ + XFEATURE_MASK_APX) /* * Features which are restored when returning to user space. @@ -49,8 +46,13 @@ /* Features which are dynamically enabled for a process on request */ #define XFEATURE_MASK_USER_DYNAMIC XFEATURE_MASK_XTILE_DATA +/* Supervisor features which are enabled only in guest FPUs */ +#define XFEATURE_MASK_GUEST_SUPERVISOR XFEATURE_MASK_CET_KERNEL + /* All currently supported supervisor features */ -#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID) +#define XFEATURE_MASK_SUPERVISOR_SUPPORTED (XFEATURE_MASK_PASID | \ + XFEATURE_MASK_CET_USER | \ + XFEATURE_MASK_GUEST_SUPERVISOR) /* * A supervisor state component may not always contain valuable information, |