[PATCH V12 13/14] RISC-V: paravirt: pvqspinlock: Add kconfig entry

[guoren]

From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>

Add kconfig entry for paravirt_spinlock, an unfair qspinlock
virtualization-friendly backend, by halting the virtual CPU rather
than spinning.

Reviewed-by: Leonardo Bras <leobras@xxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
---
 arch/riscv/Kconfig         | 12 ++++++++++++
 arch/riscv/kernel/Makefile |  1 +
 2 files changed, 13 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index b7673c5c0997..7df3d50733c6 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -780,6 +780,18 @@ config RANDOMIZE_BASE
 
           If unsure, say N.
 
+config PARAVIRT_SPINLOCKS
+	bool "Paravirtualization layer for spinlocks"
+	depends on QUEUED_SPINLOCKS
+	default y
+	help
+	  Paravirtualized spinlocks allow a unfair qspinlock to replace the
+	  test-set kvm-guest virt spinlock implementation with something
+	  virtualization-friendly, for example, halt the virtual CPU rather
+	  than spinning.
+
+	  If you are unsure how to answer this question, answer Y.
+
 endmenu # "Kernel features"
 
 menu "Boot options"
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index fee22a3d1b53..2e0754e422cf 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -102,3 +102,4 @@ obj-$(CONFIG_COMPAT)		+= compat_vdso/
 
 obj-$(CONFIG_64BIT)		+= pi/
 obj-$(CONFIG_ACPI)		+= acpi.o
+obj-$(CONFIG_PARAVIRT_SPINLOCKS) += qspinlock_paravirt.o
-- 
2.40.1