x86/fpu: Remove old KVM FPU interface

mainline inclusion
from mainline-v5.16-rc1
commit 582b01b6
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I590ZC
CVE: NA

Intel-SIG: commit 582b01b6 x86/fpu: Remove old KVM FPU interface.

--------------------------------

No more users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211022185313.074853631@linutronix.deSigned-off-by: NLin Wang <lin.x.wang@intel.com>
Signed-off-by: NAichun Shi <aichun.shi@intel.com>

arch/x86/include/asm/fpu/api.h

@@ -104,14 +104,12 @@ static inline void fpstate_init_soft(struct swregs_state *soft) {}
 DECLARE_PER_CPU(struct fpu *, fpu_fpregs_owner_ctx);
 
 /* fpstate-related functions which are exported to KVM */
-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 void fpu_copy_guest_fpstate_to_uabi(struct fpu_guest *gfpu, void *buf, unsigned int size, u32 pkru);
 extern int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, u64 xcr0, u32 *vpkru);

arch/x86/kernel/fpu/core.c

@@ -245,29 +245,6 @@ int fpu_swap_kvm_fpstate(struct fpu_guest *guest_fpu, bool enter_guest)
 }
 EXPORT_SYMBOL_GPL(fpu_swap_kvm_fpstate);
 
-void fpu_swap_kvm_fpu(struct fpu *save, struct fpu *rstor, u64 restore_mask)
-{
-	fpregs_lock();
-
-	if (save) {
-		struct fpstate *fpcur = current->thread.fpu.fpstate;
-
-		if (test_thread_flag(TIF_NEED_FPU_LOAD))
-			memcpy(&save->fpstate->regs, &fpcur->regs, fpcur->size);
-		else
-			save_fpregs_to_fpstate(save);
-	}
-
-	if (rstor) {
-		restore_mask &= XFEATURE_MASK_FPSTATE;
-		restore_fpregs_from_fpstate(rstor->fpstate, restore_mask);
-	}
-
-	fpregs_mark_activate();
-	fpregs_unlock();
-}
-EXPORT_SYMBOL_GPL(fpu_swap_kvm_fpu);
-
 void fpu_copy_guest_fpstate_to_uabi(struct fpu_guest *gfpu, void *buf,
 				    unsigned int size, u32 pkru)
 {
@@ -437,15 +414,6 @@ void fpstate_reset(struct fpu *fpu)
 	__fpstate_reset(fpu->fpstate);
 }
 
-#if IS_ENABLED(CONFIG_KVM)
-void fpu_init_fpstate_user(struct fpu *fpu)
-{
-	fpstate_reset(fpu);
-	fpstate_init_user(fpu->fpstate);
-}
-EXPORT_SYMBOL_GPL(fpu_init_fpstate_user);
-#endif
-
 /* Clone current's FPU state on fork */
 int fpu_clone(struct task_struct *dst)
 {