x86: Add support for Linux guests on an ACRN hypervisor

ACRN is an open-source hypervisor maintained by The Linux Foundation. It
is built for embedded IOT with small footprint and real-time features.
Add ACRN guest support so that it allows Linux to be booted under the
ACRN hypervisor. This adds only the barebones implementation.

 [ bp: Massage commit message and help text. ]

Co-developed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1559108037-18813-3-git-send-email-yakui.zhao@intel.com

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c9ab09004b16972e9e80bae6dfa269512aebeaf0..8a95c50e5c125f3208263e549393077a165e8240 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -835,6 +835,16 @@ config JAILHOUSE_GUEST
          cell. You can leave this option disabled if you only want to start
          Jailhouse and run Linux afterwards in the root cell.
 
+config ACRN_GUEST
+       bool "ACRN Guest support"
+       depends on X86_64
+       help
+         This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
+         a flexible, lightweight reference open-source hypervisor, built with
+         real-time and safety-criticality in mind. It is built for embedded
+         IOT with small footprint and real-time features. More details can be
+         found in https://projectacrn.org/.
+
 endif #HYPERVISOR_GUEST
 
 source "arch/x86/Kconfig.cpu"

diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h
index 8c5aaba6633f207e6374f875cd073e8bb2133464..50a30f6c668b6c5fbd7458ae3305b8381e8da93b 100644 (file)
--- a/arch/x86/include/asm/hypervisor.h
+++ b/arch/x86/include/asm/hypervisor.h
@@ -29,6 +29,7 @@ enum x86_hypervisor_type {
        X86_HYPER_XEN_HVM,
        X86_HYPER_KVM,
        X86_HYPER_JAILHOUSE,
+       X86_HYPER_ACRN,
 };
 
 #ifdef CONFIG_HYPERVISOR_GUEST

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 5102bf7c81929068a76edfc614f64be8f8a07287..3ffe1b0b751645da32fbb4dce914bedfb2437158 100644 (file)
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_X86_CPU_RESCTRL)         += resctrl/
 obj-$(CONFIG_X86_LOCAL_APIC)           += perfctr-watchdog.o
 
 obj-$(CONFIG_HYPERVISOR_GUEST)         += vmware.o hypervisor.o mshyperv.o
+obj-$(CONFIG_ACRN_GUEST)               += acrn.o
 
 ifdef CONFIG_X86_FEATURE_NAMES
 quiet_cmd_mkcapflags = MKCAP   $@

diff --git a/arch/x86/kernel/cpu/acrn.c b/arch/x86/kernel/cpu/acrn.c
new file mode 100644 (file)
index 0000000..6d365e9
--- /dev/null
+++ b/arch/x86/kernel/cpu/acrn.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACRN detection support
+ *
+ * Copyright (C) 2019 Intel Corporation. All rights reserved.
+ *
+ * Jason Chen CJ <jason.cj.chen@intel.com>
+ * Zhao Yakui <yakui.zhao@intel.com>
+ *
+ */
+
+#include <asm/hypervisor.h>
+
+static uint32_t __init acrn_detect(void)
+{
+       return hypervisor_cpuid_base("ACRNACRNACRN\0\0", 0);
+}
+
+static void __init acrn_init_platform(void)
+{
+}
+
+static bool acrn_x2apic_available(void)
+{
+       /*
+        * x2apic is not supported for now. Future enablement will have to check
+        * X86_FEATURE_X2APIC to determine whether x2apic is supported in the
+        * guest.
+        */
+       return false;
+}
+
+const __initconst struct hypervisor_x86 x86_hyper_acrn = {
+       .name                   = "ACRN",
+       .detect                 = acrn_detect,
+       .type                   = X86_HYPER_ACRN,
+       .init.init_platform     = acrn_init_platform,
+       .init.x2apic_available  = acrn_x2apic_available,
+};

diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index 479ca4728de01a698412e4499fc6ac574ef74d78..87e39ad8d873fdff2a206f18fdd78a03478ae1c5 100644 (file)
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -32,6 +32,7 @@ extern const struct hypervisor_x86 x86_hyper_xen_pv;
 extern const struct hypervisor_x86 x86_hyper_xen_hvm;
 extern const struct hypervisor_x86 x86_hyper_kvm;
 extern const struct hypervisor_x86 x86_hyper_jailhouse;
+extern const struct hypervisor_x86 x86_hyper_acrn;
 
 static const __initconst struct hypervisor_x86 * const hypervisors[] =
 {
@@ -49,6 +50,9 @@ static const __initconst struct hypervisor_x86 * const hypervisors[] =
 #ifdef CONFIG_JAILHOUSE_GUEST
        &x86_hyper_jailhouse,
 #endif
+#ifdef CONFIG_ACRN_GUEST
+       &x86_hyper_acrn,
+#endif
 };
 
 enum x86_hypervisor_type x86_hyper_type;