Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 asm updates from Ingo Molnar:
 "Misc updates:

   - Remove last remaining calls to exception_enter/exception_exit() and
     simplify the entry code some more.

   - Remove force_iret()

   - Add support for "Fast Short Rep Mov", which is available starting
     with Ice Lake Intel CPUs - and make the x86 assembly version of
     memmove() use REP MOV for all sizes when FSRM is available.

   - Micro-optimize/simplify the 32-bit boot code a bit.

   - Use a more future-proof SYSRET instruction mnemonic"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Simplify calculation of output address
  x86/entry/64: Add instruction suffix to SYSRET
  x86: Remove force_iret()
  x86/cpufeatures: Add support for fast short REP; MOVSB
  x86/context-tracking: Remove exception_enter/exit() from KVM_PV_REASON_PAGE_NOT_PRESENT async page fault
  x86/context-tracking: Remove exception_enter/exit() from do_page_fault()

5 files changed, 0 insertions, 9 deletions

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 32ef1ee733b7..81045aabb6f4 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -245,17 +245,13 @@ NOKPROBE_SYMBOL(kvm_read_and_reset_pf_reason);
 dotraplinkage void
 do_async_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address)
 {
-	enum ctx_state prev_state;
-
 	switch (kvm_read_and_reset_pf_reason()) {
 	default:
 		do_page_fault(regs, error_code, address);
 		break;
 	case KVM_PV_REASON_PAGE_NOT_PRESENT:
 		/* page is swapped out by the host. */
-		prev_state = exception_enter();
 		kvm_async_pf_task_wait((u32)address, !user_mode(regs));
-		exception_exit(prev_state);
 		break;
 	case KVM_PV_REASON_PAGE_READY:
 		rcu_irq_enter();
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 323499f48858..5052ced43373 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -124,7 +124,6 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
 	regs->ip		= new_ip;
 	regs->sp		= new_sp;
 	regs->flags		= X86_EFLAGS_IF;
-	force_iret();
 }
 EXPORT_SYMBOL_GPL(start_thread);
 
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 506d66830d4d..ffd497804dbc 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -394,7 +394,6 @@ start_thread_common(struct pt_regs *regs, unsigned long new_ip,
 	regs->cs		= _cs;
 	regs->ss		= _ss;
 	regs->flags		= X86_EFLAGS_IF;
-	force_iret();
 }
 
 void
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 8eb7193e158d..8a29573851a3 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -151,8 +151,6 @@ static int restore_sigcontext(struct pt_regs *regs,
 
 	err |= fpu__restore_sig(buf, IS_ENABLED(CONFIG_X86_32));
 
-	force_iret();
-
 	return err;
 }
 
diff --git a/arch/x86/kernel/vm86_32.c b/arch/x86/kernel/vm86_32.c
index a76c12b38e92..91d55454e702 100644
--- a/arch/x86/kernel/vm86_32.c
+++ b/arch/x86/kernel/vm86_32.c
@@ -381,7 +381,6 @@ static long do_sys_vm86(struct vm86plus_struct __user *user_vm86, bool plus)
 		mark_screen_rdonly(tsk->mm);
 
 	memcpy((struct kernel_vm86_regs *)regs, &vm86regs, sizeof(vm86regs));
-	force_iret();
 	return regs->ax;
 }