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

Pull x86 FPU updates from Ingo Molnar:
 "The main changes in this cycle were:

   - do a large round of simplifications after all CPUs do 'eager' FPU
     context switching in v4.9: remove CR0 twiddling, remove leftover
     eager/lazy bts, etc (Andy Lutomirski)

   - more FPU code simplifications: remove struct fpu::counter, clarify
     nomenclature, remove unnecessary arguments/functions and better
     structure the code (Rik van Riel)"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Remove clts()
  x86/fpu: Remove stts()
  x86/fpu: Handle #NM without FPU emulation as an error
  x86/fpu, lguest: Remove CR0.TS support
  x86/fpu, kvm: Remove host CR0.TS manipulation
  x86/fpu: Remove irq_ts_save() and irq_ts_restore()
  x86/fpu: Stop saving and restoring CR0.TS in fpu__init_check_bugs()
  x86/fpu: Get rid of two redundant clts() calls
  x86/fpu: Finish excising 'eagerfpu'
  x86/fpu: Split old_fpu & new_fpu handling into separate functions
  x86/fpu: Remove 'cpu' argument from __cpu_invalidate_fpregs_state()
  x86/fpu: Split old & new FPU code paths
  x86/fpu: Remove __fpregs_(de)activate()
  x86/fpu: Rename lazy restore functions to "register state valid"
  x86/fpu, kvm: Remove KVM vcpu->fpu_counter
  x86/fpu: Remove struct fpu::counter
  x86/fpu: Remove use_eager_fpu()
  x86/fpu: Remove the XFEATURE_MASK_EAGER/LAZY distinction
  x86/fpu: Hard-disable lazy FPU mode
  x86/crypto, x86/fpu: Remove X86_FEATURE_EAGER_FPU #ifdef from the crc32c code

1 files changed, 1 insertions, 18 deletions

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. */