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

Pull misc x86 fixes from Ingo Molnar:

 - make CR4 handling irq-safe, which bug vmware guests ran into

 - don't crash on early IRQs in Xen guests

 - don't crash secondary CPU bringup if #UD assisted WARN()ings are
   triggered

 - make X86_BUG_FXSAVE_LEAK optional on newer AMD CPUs that have the fix

 - fix AMD Fam17h microcode loading

 - fix broadcom_postcore_init() if ACPI is disabled

 - fix resume regression in __restore_processor_context()

 - fix Sparse warnings

 - fix a GCC-8 warning

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso: Change time() prototype to match __vdso_time()
  x86: Fix Sparse warnings about non-static functions
  x86/power: Fix some ordering bugs in __restore_processor_context()
  x86/PCI: Make broadcom_postcore_init() check acpi_disabled
  x86/microcode/AMD: Add support for fam17h microcode loading
  x86/cpufeatures: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
  x86/idt: Load idt early in start_secondary
  x86/xen: Support early interrupts in xen pv guests
  x86/tlb: Disable interrupts when changing CR4
  x86/tlb: Refactor CR4 setting and shadow write

3 files changed, 32 insertions, 16 deletions

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index c0b0e9e8aa66..800104c8a3ed 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -266,6 +266,7 @@
 /* AMD-defined CPU features, CPUID level 0x80000008 (EBX), word 13 */
 #define X86_FEATURE_CLZERO		(13*32+ 0) /* CLZERO instruction */
 #define X86_FEATURE_IRPERF		(13*32+ 1) /* Instructions Retired Count */
+#define X86_FEATURE_XSAVEERPTR		(13*32+ 2) /* Always save/restore FP error pointers */
 
 /* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
 #define X86_FEATURE_DTHERM		(14*32+ 0) /* Digital Thermal Sensor */
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index b20f9d623f9c..8f09012b92e7 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -236,11 +236,23 @@
  */
 #define EARLY_IDT_HANDLER_SIZE 9
 
+/*
+ * xen_early_idt_handler_array is for Xen pv guests: for each entry in
+ * early_idt_handler_array it contains a prequel in the form of
+ * pop %rcx; pop %r11; jmp early_idt_handler_array[i]; summing up to
+ * max 8 bytes.
+ */
+#define XEN_EARLY_IDT_HANDLER_SIZE 8
+
 #ifndef __ASSEMBLY__
 
 extern const char early_idt_handler_array[NUM_EXCEPTION_VECTORS][EARLY_IDT_HANDLER_SIZE];
 extern void early_ignore_irq(void);
 
+#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
+extern const char xen_early_idt_handler_array[NUM_EXCEPTION_VECTORS][XEN_EARLY_IDT_HANDLER_SIZE];
+#endif
+
 /*
  * Load a segment. Fall back on loading the zero segment if something goes
  * wrong.  This variant assumes that loading zero fully clears the segment.
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 509046cfa5ce..877b5c1a1b12 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -173,40 +173,43 @@ static inline void cr4_init_shadow(void)
 	this_cpu_write(cpu_tlbstate.cr4, __read_cr4());
 }
 
+static inline void __cr4_set(unsigned long cr4)
+{
+	lockdep_assert_irqs_disabled();
+	this_cpu_write(cpu_tlbstate.cr4, cr4);
+	__write_cr4(cr4);
+}
+
 /* Set in this cpu's CR4. */
 static inline void cr4_set_bits(unsigned long mask)
 {
-	unsigned long cr4;
+	unsigned long cr4, flags;
 
+	local_irq_save(flags);
 	cr4 = this_cpu_read(cpu_tlbstate.cr4);
-	if ((cr4 | mask) != cr4) {
-		cr4 |= mask;
-		this_cpu_write(cpu_tlbstate.cr4, cr4);
-		__write_cr4(cr4);
-	}
+	if ((cr4 | mask) != cr4)
+		__cr4_set(cr4 | mask);
+	local_irq_restore(flags);
 }
 
 /* Clear in this cpu's CR4. */
 static inline void cr4_clear_bits(unsigned long mask)
 {
-	unsigned long cr4;
+	unsigned long cr4, flags;
 
+	local_irq_save(flags);
 	cr4 = this_cpu_read(cpu_tlbstate.cr4);
-	if ((cr4 & ~mask) != cr4) {
-		cr4 &= ~mask;
-		this_cpu_write(cpu_tlbstate.cr4, cr4);
-		__write_cr4(cr4);
-	}
+	if ((cr4 & ~mask) != cr4)
+		__cr4_set(cr4 & ~mask);
+	local_irq_restore(flags);
 }
 
-static inline void cr4_toggle_bits(unsigned long mask)
+static inline void cr4_toggle_bits_irqsoff(unsigned long mask)
 {
 	unsigned long cr4;
 
 	cr4 = this_cpu_read(cpu_tlbstate.cr4);
-	cr4 ^= mask;
-	this_cpu_write(cpu_tlbstate.cr4, cr4);
-	__write_cr4(cr4);
+	__cr4_set(cr4 ^ mask);
 }
 
 /* Read the CR4 shadow. */