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authorAndy Lutomirski <luto@kernel.org>2016-10-31 15:18:46 -0700
committerIngo Molnar <mingo@kernel.org>2016-11-01 07:47:54 +0100
commitcd95ea81f25608c403052d0508ee5c9b32e2bc7d (patch)
treeb5901aa76a2882cf4e722faa33b430945455d1dc /drivers/lguest
parent04ac88abaf758bd76edcc3be5549003a017e7963 (diff)
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x86/fpu, lguest: Remove CR0.TS support
Now that Linux never sets CR0.TS, lguest doesn't need to support it. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm list <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/8a7bf2c11231c082258fd67705d0f275639b8475.1477951965.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/lguest')
-rw-r--r--drivers/lguest/hypercalls.c4
-rw-r--r--drivers/lguest/lg.h1
-rw-r--r--drivers/lguest/x86/core.c19
3 files changed, 1 insertions, 23 deletions
diff --git a/drivers/lguest/hypercalls.c b/drivers/lguest/hypercalls.c
index 19a32280731d..601f81c04873 100644
--- a/drivers/lguest/hypercalls.c
+++ b/drivers/lguest/hypercalls.c
@@ -109,10 +109,6 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
case LHCALL_SET_CLOCKEVENT:
guest_set_clockevent(cpu, args->arg1);
break;
- case LHCALL_TS:
- /* This sets the TS flag, as we saw used in run_guest(). */
- cpu->ts = args->arg1;
- break;
case LHCALL_HALT:
/* Similarly, this sets the halted flag for run_guest(). */
cpu->halted = 1;
diff --git a/drivers/lguest/lg.h b/drivers/lguest/lg.h
index 69b3814afd2f..2356a2318034 100644
--- a/drivers/lguest/lg.h
+++ b/drivers/lguest/lg.h
@@ -43,7 +43,6 @@ struct lg_cpu {
struct mm_struct *mm; /* == tsk->mm, but that becomes NULL on exit */
u32 cr2;
- int ts;
u32 esp1;
u16 ss1;
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. */