Received-SPF: pass (google.com: domain of linux-kernel+bounces-11055-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
From: guoren@kernel.org
To: paul.walmsley@sifive.com,
	palmer@dabbelt.com,
	guoren@kernel.org,
	panqinglin2020@iscas.ac.cn,
	bjorn@rivosinc.com,
	conor.dooley@microchip.com,
	leobras@redhat.com,
	peterz@infradead.org,
	anup@brainfault.org,
	keescook@chromium.org,
	wuwei2016@iscas.ac.cn,
	xiaoguang.xing@sophgo.com,
	chao.wei@sophgo.com,
	unicorn_wang@outlook.com,
	uwu@icenowy.me,
	jszhang@kernel.org,
	wefu@redhat.com,
	atishp@atishpatra.org
Cc: linux-riscv@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	Guo Ren <guoren@linux.alibaba.com>
Subject: [PATCH V12 13/14] RISC-V: paravirt: pvqspinlock: Add kconfig entry
Date: Mon, 25 Dec 2023 07:58:46 -0500
Message-Id: <20231225125847.2778638-14-guoren@kernel.org>
In-Reply-To: <20231225125847.2778638-1-guoren@kernel.org>
References: <20231225125847.2778638-1-guoren@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

From: Guo Ren <guoren@linux.alibaba.com>

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@redhat.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
 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