From 46ce2e7480b936cab36cddeac98efe96e9c2ff97 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex.bennee@linaro.org>
Date: Thu, 11 Sep 2025 22:27:44 +0100
Subject: [PATCH] package/qemu: introduce kvm and tcg system options
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When building system binaries you may not even want TCG support if you
are only intending to use KVM. Provide the options so the user can
select only what they need.

With only KVM selected the QEMU build will generally only build the
binary for your target system. We keep TCG support on by default so as
not to break existing defconfigs.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 package/qemu/Config.in | 25 ++++++++++++++++++++-----
 package/qemu/qemu.mk   | 14 +++++++++++++-
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/package/qemu/Config.in b/package/qemu/Config.in
index ff7423bc4c..e16eafe446 100644
--- a/package/qemu/Config.in
+++ b/package/qemu/Config.in
@@ -54,11 +54,27 @@ config BR2_PACKAGE_QEMU_SYSTEM
 	depends on !BR2_STATIC_LIBS # dtc
 	select BR2_PACKAGE_PIXMAN
 	select BR2_PACKAGE_QEMU_FDT if !BR2_PACKAGE_QEMU_CHOOSE_TARGETS
+	# Make sure at least one of tcg or kvm is enabled
+	select BR2_PACKAGE_QEMU_SYSTEM_TCG if !BR2_PACKAGE_QEMU_SYSTEM_KVM
 	help
 	  Say 'y' to build system emulators/virtualisers.
 
 if BR2_PACKAGE_QEMU_SYSTEM
 
+config BR2_PACKAGE_QEMU_SYSTEM_KVM
+	bool "Enable KVM system virtualisation"
+	default y
+	help
+	  Say 'y' here to enable a QEMU with KVM support.
+	  If unsure, say 'y'
+
+config BR2_PACKAGE_QEMU_SYSTEM_TCG
+	bool "Enable TCG system emulation"
+	default y
+	help
+	  Say 'y' here to enable QEMU binaries which can emulate foreign
+	  architectures using the TCG JIT.
+
 config BR2_PACKAGE_QEMU_BLOBS
 	bool "Install binary blobs"
 	default y
@@ -130,12 +146,11 @@ config BR2_PACKAGE_QEMU_LINUX_USER
 
 config BR2_PACKAGE_QEMU_CHOOSE_TARGETS
 	bool "Select individual emulator targets"
-	depends on BR2_PACKAGE_QEMU_SYSTEM || BR2_PACKAGE_QEMU_LINUX_USER
+	depends on BR2_PACKAGE_QEMU_SYSTEM_TCG || BR2_PACKAGE_QEMU_LINUX_USER
 	help
-	  By default, all targets (system and/or user, subject to the
-	  corresponding options, above) are built. If you only need a
-	  subset of the emulated targets, say 'y' here and enable at
-	  least one target, below.
+	  By default, all targets system targets are built. If you
+	  only need a subset of the emulated targets, say 'y' here and
+	  enable at least one target, below.
 
 if BR2_PACKAGE_QEMU_CHOOSE_TARGETS
 
diff --git a/package/qemu/qemu.mk b/package/qemu/qemu.mk
index 1672ac8f19..97f8e22091 100644
--- a/package/qemu/qemu.mk
+++ b/package/qemu/qemu.mk
@@ -48,6 +48,19 @@ QEMU_VARS = LIBTOOL=$(HOST_DIR)/bin/libtool
 ifeq ($(BR2_PACKAGE_QEMU_SYSTEM),y)
 QEMU_DEPENDENCIES += pixman
 QEMU_OPTS += --enable-system
+
+ifeq ($(BR2_PACKAGE_QEMU_SYSTEM_KVM), y)
+QEMU_OPTS += --enable-kvm
+else
+QEMU_OPTS += --disable-kvm
+endif
+
+ifeq ($(BR2_PACKAGE_QEMU_SYSTEM_TCG), y)
+QEMU_OPTS += --enable-tcg
+else
+QEMU_OPTS += --disable-tcg
+endif
+
 QEMU_TARGET_LIST_$(BR2_PACKAGE_QEMU_TARGET_AARCH64) += aarch64-softmmu
 QEMU_TARGET_LIST_$(BR2_PACKAGE_QEMU_TARGET_ALPHA) += alpha-softmmu
 QEMU_TARGET_LIST_$(BR2_PACKAGE_QEMU_TARGET_ARM) += arm-softmmu
@@ -333,7 +346,6 @@ define QEMU_CONFIGURE_CMDS
 			--disable-whpx \
 			--disable-xen \
 			--enable-attr \
-			--enable-kvm \
 			--enable-vhost-net \
 			--disable-download \
 			--disable-hexagon-idef-parser \