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 <yakui.zhao@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: linux-hyperv@vger.kernel.org
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/1559108037-18813-2-git-send-email-yakui.zhao@intel.com

5 files changed, 7 insertions, 2 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2bbbd4d1ba31..c9ab09004b16 100644
--- a/arch/x86/Kconfig
+++ b/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
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index d9069bb26c7f..07533795b8d2 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/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)
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 9b68b5b00ac9..4e8f193ad81f 100644
--- a/arch/x86/kernel/irq.c
+++ b/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)
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index e07abefd3d26..ba5a41828e9d 100644
--- a/arch/x86/xen/Kconfig
+++ b/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
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 1c1a2514d6f3..cafcb974dcfe 100644
--- a/drivers/hv/Kconfig
+++ b/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.