boards/qemu/x86: Add qemu_x86_64_kvm

New kvm-enabled qemu board definition, which also includes CET
support. Note that to have CET support on qemu, one needs a fairly
recent Linux kernel (at least 6.18) and qemu (at least version 11.0).

Also note that current Zephyr SDK (as of this patch, 1.0.1) qemu-x86_64
does not support CET (as it's still on version 10.x). So to use it, one
needs to point to a supporting qemu (for instance, by using
`QEMU_BIN_PATH` when building).

Signed-off-by: Ederson de Souza <ederson.desouza@intel.com>

Author: edersondisouza

boards/qemu/x86/Kconfig

@@ -6,4 +6,5 @@ config BOARD_QEMU_X86
 	bool
 	default y
 	select CPU_HAS_FPU if BOARD_QEMU_X86 || BOARD_QEMU_X86_LAKEMONT || BOARD_QEMU_X86_TINY
-	select X86_64 if BOARD_QEMU_X86_64
+	select X86_64 if BOARD_QEMU_X86_64 || BOARD_QEMU_X86_64_KVM
+	select X86_CPU_HAS_CET if BOARD_QEMU_X86_64_KVM

boards/qemu/x86/Kconfig.defconfig

@@ -1,7 +1,8 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (c) 2019 Intel Corp.
 
-if BOARD_QEMU_X86 || BOARD_QEMU_X86_64 || BOARD_QEMU_X86_LAKEMONT || BOARD_QEMU_X86_TINY
+if BOARD_QEMU_X86 || BOARD_QEMU_X86_64 || BOARD_QEMU_X86_LAKEMONT || BOARD_QEMU_X86_TINY || \
+	BOARD_QEMU_X86_64_KVM
 
 # The EEPROM emulator must be initialized after the flash simulator
 config EEPROM_INIT_PRIORITY
@@ -17,7 +18,7 @@ config QEMU_TARGET
 config HAS_COVERAGE_SUPPORT
 	default y
 
-endif # BOARD_QEMU_X86 || BOARD_QEMU_X86_64 || BOARD_QEMU_X86_LAKEMONT || BOARD_QEMU_X86_TINY
+endif # BOARD_QEMU_X86 || BOARD_QEMU_X86_64 || BOARD_QEMU_X86_LAKEMONT || BOARD_QEMU_X86_TINY...
 
 
 if BOARD_QEMU_X86
@@ -47,7 +48,7 @@ config QEMU_ICOUNT_SHIFT
 endif # BOARD_QEMU_X86
 
 
-if BOARD_QEMU_X86_64
+if BOARD_QEMU_X86_64 || BOARD_QEMU_X86_64_KVM
 
 config KERNEL_VM_SIZE
 	default 0x10000000 if ACPI
@@ -107,3 +108,10 @@ config DEMAND_PAGING_PAGE_FRAMES_RESERVE
 	default 6 if NEWLIB_LIBC || (COMMON_LIBC_MALLOC && COMMON_LIBC_MALLOC_ARENA_SIZE != 0)
 
 endif # BOARD_QEMU_X86_TINY
+
+if BOARD_QEMU_X86_64_KVM
+
+config SYS_CLOCK_HW_CYCLES_PER_SEC
+	default $(dt_node_int_prop_int,/cpus/cpu@0,clock-frequency)
+
+endif # BOARD_QEMU_X86_64_KVM

boards/qemu/x86/Kconfig.qemu_x86_64_kvm

@@ -0,0 +1,6 @@
+# Copyright (c) 2026 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+config BOARD_QEMU_X86_64_KVM
+	select SOC_ATOM

boards/qemu/x86/board.cmake

@@ -3,7 +3,11 @@
 
 set(SUPPORTED_EMU_PLATFORMS qemu)
 
-if(CONFIG_X86_64)
+if(CONFIG_BOARD_QEMU_X86_64_KVM)
+  set(QEMU_BINARY_SUFFIX x86_64)
+  set(QEMU_CPU_TYPE host,+x2apic)
+  list(APPEND QEMU_EXTRA_FLAGS -rtc clock=vm --enable-kvm)
+elseif(CONFIG_X86_64)
   set(QEMU_BINARY_SUFFIX x86_64)
   set(QEMU_CPU_TYPE qemu64,+x2apic)
   if("${CONFIG_MP_MAX_NUM_CPUS}" STREQUAL "1")

boards/qemu/x86/board.yml

@@ -31,3 +31,10 @@ boards:
     vendor: intel
     socs:
       - name: atom
+
+  - name: qemu_x86_64_kvm
+    full_name: QEMU Emulation for X86 64bit, KVM enabled
+    socs:
+      - name: atom
+        variants:
+          - name: 'nokpti'

boards/qemu/x86/qemu_x86_64_kvm.dts

@@ -0,0 +1,9 @@
+/*
+ * Copyright (c) 2026 Intel Corp.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include "qemu_x86_64.dts"
+
+&cpu {
+	clock-frequency = <25000000>;
+};

boards/qemu/x86/qemu_x86_64_kvm.yaml

@@ -0,0 +1,16 @@
+identifier: qemu_x86_64_kvm
+name: QEMU Emulation for X86_64 (KVM enabled)
+type: qemu
+arch: x86
+toolchain:
+  - zephyr
+supported:
+  - smp
+simulation:
+  - name: qemu
+testing:
+  default: false
+  ignore_tags:
+    - benchmark
+    - kernel
+vendor: qemu

boards/qemu/x86/qemu_x86_64_kvm_defconfig

@@ -0,0 +1,13 @@
+CONFIG_PICOLIBC_USE_MODULE=y
+CONFIG_PIC_DISABLE=y
+CONFIG_LOAPIC=y
+CONFIG_CONSOLE=y
+CONFIG_SERIAL=y
+CONFIG_UART_CONSOLE=y
+CONFIG_TEST_RANDOM_GENERATOR=y
+CONFIG_X86_DEBUG_INFO=y
+CONFIG_SMP=y
+CONFIG_MP_MAX_NUM_CPUS=2
+CONFIG_X86_MMU=y
+CONFIG_X86_VERY_EARLY_CONSOLE=y
+CONFIG_QEMU_ICOUNT=n