diff options
| -rw-r--r-- | arch/x86/include/asm/fpu/api.h | 13 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 85 |
2 files changed, 92 insertions, 6 deletions
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 9ce83148058f..de85bcaae0c3 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -135,9 +135,22 @@ extern void fpu_init_fpstate_user(struct fpu *fpu); extern void fpstate_clear_xstate_component(struct fpstate *fps, unsigned int xfeature); /* KVM specific functions */ +extern bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu); +extern void fpu_free_guest_fpstate(struct fpu_guest *gfpu); +extern int fpu_swap_kvm_fpstate(struct fpu_guest *gfpu, bool enter_guest); extern void fpu_swap_kvm_fpu(struct fpu *save, struct fpu *rstor, u64 restore_mask); extern int fpu_copy_kvm_uabi_to_fpstate(struct fpu *fpu, const void *buf, u64 xcr0, u32 *pkru); extern void fpu_copy_fpstate_to_kvm_uabi(struct fpu *fpu, void *buf, unsigned int size, u32 pkru); +static inline void fpstate_set_confidential(struct fpu_guest *gfpu) +{ + gfpu->fpstate->is_confidential = true; +} + +static inline bool fpstate_is_confidential(struct fpu_guest *gfpu) +{ + return gfpu->fpstate->is_confidential; +} + #endif /* _ASM_X86_FPU_API_H */ diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 0fb9defaba47..748d7b2fcacb 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -176,6 +176,75 @@ void fpu_reset_from_exception_fixup(void) } #if IS_ENABLED(CONFIG_KVM) +static void __fpstate_reset(struct fpstate *fpstate); + +bool fpu_alloc_guest_fpstate(struct fpu_guest *gfpu) +{ + struct fpstate *fpstate; + unsigned int size; + + size = fpu_user_cfg.default_size + ALIGN(offsetof(struct fpstate, regs), 64); + fpstate = vzalloc(size); + if (!fpstate) + return false; + + __fpstate_reset(fpstate); + fpstate_init_user(fpstate); + fpstate->is_valloc = true; + fpstate->is_guest = true; + + gfpu->fpstate = fpstate; + return true; +} +EXPORT_SYMBOL_GPL(fpu_alloc_guest_fpstate); + +void fpu_free_guest_fpstate(struct fpu_guest *gfpu) +{ + struct fpstate *fps = gfpu->fpstate; + + if (!fps) + return; + + if (WARN_ON_ONCE(!fps->is_valloc || !fps->is_guest || fps->in_use)) + return; + + gfpu->fpstate = NULL; + vfree(fps); +} +EXPORT_SYMBOL_GPL(fpu_free_guest_fpstate); + +int fpu_swap_kvm_fpstate(struct fpu_guest *guest_fpu, bool enter_guest) +{ + struct fpstate *guest_fps = guest_fpu->fpstate; + struct fpu *fpu = ¤t->thread.fpu; + struct fpstate *cur_fps = fpu->fpstate; + + fpregs_lock(); + if (!cur_fps->is_confidential && !test_thread_flag(TIF_NEED_FPU_LOAD)) + save_fpregs_to_fpstate(fpu); + + /* Swap fpstate */ + if (enter_guest) { + fpu->__task_fpstate = cur_fps; + fpu->fpstate = guest_fps; + guest_fps->in_use = true; + } else { + guest_fps->in_use = false; + fpu->fpstate = fpu->__task_fpstate; + fpu->__task_fpstate = NULL; + } + + cur_fps = fpu->fpstate; + + if (!cur_fps->is_confidential) + restore_fpregs_from_fpstate(cur_fps, XFEATURE_MASK_FPSTATE); + + fpregs_mark_activate(); + fpregs_unlock(); + return 0; +} +EXPORT_SYMBOL_GPL(fpu_swap_kvm_fpstate); + void fpu_swap_kvm_fpu(struct fpu *save, struct fpu *rstor, u64 restore_mask) { fpregs_lock(); @@ -352,16 +421,20 @@ void fpstate_init_user(struct fpstate *fpstate) fpstate_init_fstate(fpstate); } +static void __fpstate_reset(struct fpstate *fpstate) +{ + /* Initialize sizes and feature masks */ + fpstate->size = fpu_kernel_cfg.default_size; + fpstate->user_size = fpu_user_cfg.default_size; + fpstate->xfeatures = fpu_kernel_cfg.default_features; + fpstate->user_xfeatures = fpu_user_cfg.default_features; +} + void fpstate_reset(struct fpu *fpu) { /* Set the fpstate pointer to the default fpstate */ fpu->fpstate = &fpu->__fpstate; - - /* Initialize sizes and feature masks */ - fpu->fpstate->size = fpu_kernel_cfg.default_size; - fpu->fpstate->user_size = fpu_user_cfg.default_size; - fpu->fpstate->xfeatures = fpu_kernel_cfg.default_features; - fpu->fpstate->user_xfeatures = fpu_user_cfg.default_features; + __fpstate_reset(fpu->fpstate); } #if IS_ENABLED(CONFIG_KVM) |