x86/Kconfig: Add new X86_HV_CALLBACK_VECTOR config symbol

Add a special Kconfig symbol X86_HV_CALLBACK_VECTOR so that the guests
using the hypervisor interrupt callback counter can select and thus
enable that counter. Select it when xen or hyperv support is enabled. No
functional changes.

Signed-off-by: Zhao Yakui <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Borislav Petkov <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: "K. Y. Srinivasan" <[email protected]>
Cc: [email protected]
Cc: Nicolai Stange <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sasha Levin <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: x86-ml <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

Author: yakuizhao

arch/x86/Kconfig

@@ -781,6 +781,9 @@ config PARAVIRT_SPINLOCKS
 
 	  If you are unsure how to answer this question, answer Y.
 
+config X86_HV_CALLBACK_VECTOR
+	def_bool n
+
 source "arch/x86/xen/Kconfig"
 
 config KVM_GUEST

arch/x86/include/asm/hardirq.h

@@ -37,7 +37,7 @@ typedef struct {
 #ifdef CONFIG_X86_MCE_AMD
 	unsigned int irq_deferred_error_count;
 #endif
-#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
+#ifdef CONFIG_X86_HV_CALLBACK_VECTOR
 	unsigned int irq_hv_callback_count;
 #endif
 #if IS_ENABLED(CONFIG_HYPERV)

arch/x86/kernel/irq.c

@@ -135,7 +135,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 		seq_printf(p, "%10u ", per_cpu(mce_poll_count, j));
 	seq_puts(p, "  Machine check polls\n");
 #endif
-#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
+#ifdef CONFIG_X86_HV_CALLBACK_VECTOR
 	if (test_bit(HYPERVISOR_CALLBACK_VECTOR, system_vectors)) {
 		seq_printf(p, "%*s: ", prec, "HYP");
 		for_each_online_cpu(j)

arch/x86/xen/Kconfig

@@ -7,6 +7,7 @@ config XEN
 	bool "Xen guest support"
 	depends on PARAVIRT
 	select PARAVIRT_CLOCK
+	select X86_HV_CALLBACK_VECTOR
 	depends on X86_64 || (X86_32 && X86_PAE)
 	depends on X86_LOCAL_APIC && X86_TSC
 	help

drivers/hv/Kconfig

@@ -6,6 +6,7 @@ config HYPERV
 	tristate "Microsoft Hyper-V client drivers"
 	depends on X86 && ACPI && X86_LOCAL_APIC && HYPERVISOR_GUEST
 	select PARAVIRT
+	select X86_HV_CALLBACK_VECTOR
 	help
 	  Select this option to run Linux as a Hyper-V client operating
 	  system.