Merge tag 'x86_alternatives_for_v5.13' of git://git.kernel.org/pub/sc…

…m/linux/kernel/git/tip/tip

Pull x86 alternatives/paravirt updates from Borislav Petkov:
 "First big cleanup to the paravirt infra to use alternatives and thus
  eliminate custom code patching.

  For that, the alternatives infrastructure is extended to accomodate
  paravirt's needs and, as a result, a lot of paravirt patching code
  goes away, leading to a sizeable cleanup and simplification.

  Work by Juergen Gross"

* tag 'x86_alternatives_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/paravirt: Have only one paravirt patch function
  x86/paravirt: Switch functions with custom code to ALTERNATIVE
  x86/paravirt: Add new PVOP_ALT* macros to support pvops in ALTERNATIVEs
  x86/paravirt: Switch iret pvops to ALTERNATIVE
  x86/paravirt: Simplify paravirt macros
  x86/paravirt: Remove no longer needed 32-bit pvops cruft
  x86/paravirt: Add new features for paravirt patching
  x86/alternative: Use ALTERNATIVE_TERNARY() in _static_cpu_has()
  x86/alternative: Support ALTERNATIVE_TERNARY
  x86/alternative: Support not-feature
  x86/paravirt: Switch time pvops functions to use static_call()
  static_call: Add function to query current function
  static_call: Move struct static_call_key definition to static_call_types.h
  x86/alternative: Merge include files
  x86/alternative: Drop unused feature parameter from ALTINSTR_REPLACEMENT()

arch/arm/include/asm/paravirt.h

@@ -3,23 +3,19 @@
 #define _ASM_ARM_PARAVIRT_H
 
 #ifdef CONFIG_PARAVIRT
+#include <linux/static_call_types.h>
+
 struct static_key;
 extern struct static_key paravirt_steal_enabled;
 extern struct static_key paravirt_steal_rq_enabled;
 
-struct pv_time_ops {
-	unsigned long long (*steal_clock)(int cpu);
-};
-
-struct paravirt_patch_template {
-	struct pv_time_ops time;
-};
+u64 dummy_steal_clock(int cpu);
 
-extern struct paravirt_patch_template pv_ops;
+DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock);
 
 static inline u64 paravirt_steal_clock(int cpu)
 {
-	return pv_ops.time.steal_clock(cpu);
+	return static_call(pv_steal_clock)(cpu);
 }
 #endif
 

arch/arm/kernel/paravirt.c

@@ -9,10 +9,15 @@
 #include <linux/export.h>
 #include <linux/jump_label.h>
 #include <linux/types.h>
+#include <linux/static_call.h>
 #include <asm/paravirt.h>
 
 struct static_key paravirt_steal_enabled;
 struct static_key paravirt_steal_rq_enabled;
 
-struct paravirt_patch_template pv_ops;
-EXPORT_SYMBOL_GPL(pv_ops);
+static u64 native_steal_clock(int cpu)
+{
+	return 0;
+}
+
+DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);

arch/arm64/include/asm/paravirt.h

@@ -3,23 +3,19 @@
 #define _ASM_ARM64_PARAVIRT_H
 
 #ifdef CONFIG_PARAVIRT
+#include <linux/static_call_types.h>
+
 struct static_key;
 extern struct static_key paravirt_steal_enabled;
 extern struct static_key paravirt_steal_rq_enabled;
 
-struct pv_time_ops {
-	unsigned long long (*steal_clock)(int cpu);
-};
-
-struct paravirt_patch_template {
-	struct pv_time_ops time;
-};
+u64 dummy_steal_clock(int cpu);
 
-extern struct paravirt_patch_template pv_ops;
+DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock);
 
 static inline u64 paravirt_steal_clock(int cpu)
 {
-	return pv_ops.time.steal_clock(cpu);
+	return static_call(pv_steal_clock)(cpu);
 }
 
 int __init pv_time_init(void);

arch/arm64/kernel/paravirt.c

@@ -18,6 +18,7 @@
 #include <linux/reboot.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/static_call.h>
 
 #include <asm/paravirt.h>
 #include <asm/pvclock-abi.h>
@@ -26,8 +27,12 @@
 struct static_key paravirt_steal_enabled;
 struct static_key paravirt_steal_rq_enabled;
 
-struct paravirt_patch_template pv_ops;
-EXPORT_SYMBOL_GPL(pv_ops);
+static u64 native_steal_clock(int cpu)
+{
+	return 0;
+}
+
+DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
 
 struct pv_time_stolen_time_region {
 	struct pvclock_vcpu_stolen_time *kaddr;
@@ -45,7 +50,7 @@ static int __init parse_no_stealacc(char *arg)
 early_param("no-steal-acc", parse_no_stealacc);
 
 /* return stolen time in ns by asking the hypervisor */
-static u64 pv_steal_clock(int cpu)
+static u64 para_steal_clock(int cpu)
 {
 	struct pv_time_stolen_time_region *reg;
 
@@ -150,7 +155,7 @@ int __init pv_time_init(void)
 	if (ret)
 		return ret;
 
-	pv_ops.time.steal_clock = pv_steal_clock;
+	static_call_update(pv_steal_clock, para_steal_clock);
 
 	static_key_slow_inc(&paravirt_steal_enabled);
 	if (steal_acc)

arch/x86/Kconfig

@@ -777,6 +777,7 @@ if HYPERVISOR_GUEST
 
 config PARAVIRT
 	bool "Enable paravirtualization code"
+	depends on HAVE_STATIC_CALL
 	help
 	  This changes the kernel so it can modify itself when it is run
 	  under a hypervisor, potentially improving performance significantly

arch/x86/entry/entry_32.S

@@ -40,7 +40,7 @@
 #include <asm/processor-flags.h>
 #include <asm/irq_vectors.h>
 #include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
 #include <asm/asm.h>
 #include <asm/smap.h>
 #include <asm/frame.h>
@@ -430,7 +430,7 @@
 	 * will soon execute iret and the tracer was already set to
 	 * the irqstate after the IRET:
 	 */
-	DISABLE_INTERRUPTS(CLBR_ANY)
+	cli
 	lss	(%esp), %esp			/* switch to espfix segment */
 .Lend_\@:
 #endif /* CONFIG_X86_ESPFIX32 */
@@ -1077,7 +1077,7 @@ restore_all_switch_stack:
 	 * when returning from IPI handler and when returning from
 	 * scheduler to user-space.
 	 */
-	INTERRUPT_RETURN
+	iret
 
 .section .fixup, "ax"
 SYM_CODE_START(asm_iret_error)

arch/x86/entry/entry_64.S

@@ -305,7 +305,7 @@ SYM_CODE_END(ret_from_fork)
 .macro DEBUG_ENTRY_ASSERT_IRQS_OFF
 #ifdef CONFIG_DEBUG_ENTRY
 	pushq %rax
-	SAVE_FLAGS(CLBR_RAX)
+	SAVE_FLAGS
 	testl $X86_EFLAGS_IF, %eax
 	jz .Lokay_\@
 	ud2

arch/x86/entry/vdso/vdso32/system_call.S

@@ -6,7 +6,7 @@
 #include <linux/linkage.h>
 #include <asm/dwarf2.h>
 #include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
 
 	.text
 	.globl __kernel_vsyscall