Legacy VirtIO devices don't have their endianness clearly defined.
QEMU infers it taking the endianness of the (target) binary, or,
when a target support switching endianness at runtime, taking the
endianness of the vCPU accessing the device.
Devices modelling shouldn't really change depending on a property
of a CPU accessing it.
For heterogeneous systems, it is simpler to break such dev <-> cpu
dependency, only allowing generic device models, with no knowledge
of CPU (or DMA controller) accesses.
Therefore we introduce the VIRTIO_LEGACY Kconfig key. We keep the
current default (enabled).
New binaries can set CONFIG_VIRTIO_LEGACY=n to restrict models to
the VirtIO version 1 spec.
Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
---
include/hw/virtio/virtio-access.h | 5 ++++-
hw/virtio/virtio.c | 8 ++++++++
target/arm/cpu.c | 5 +++++
target/ppc/cpu_init.c | 5 +++++
hw/virtio/Kconfig | 5 +++++
5 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/include/hw/virtio/virtio-access.h
b/include/hw/virtio/virtio-access.h
index 07aae69042a..b5b471711a6 100644
--- a/include/hw/virtio/virtio-access.h
+++ b/include/hw/virtio/virtio-access.h
@@ -20,7 +20,10 @@
#include "hw/virtio/virtio.h"
#include "hw/virtio/virtio-bus.h"
-#if defined(TARGET_PPC64) || defined(TARGET_ARM)
+#include CONFIG_DEVICES
+
+#if defined(CONFIG_VIRTIO_LEGACY) && \
+ (defined(TARGET_PPC64) || defined(TARGET_ARM))
#define LEGACY_VIRTIO_IS_BIENDIAN 1
#endif
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 480c2e50365..659ab3cb969 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -47,6 +47,8 @@
#include "standard-headers/linux/virtio_mem.h"
#include "standard-headers/linux/virtio_vsock.h"
+#include CONFIG_DEVICES
+
/*
* Maximum size of virtio device config space
*/
@@ -3502,6 +3504,7 @@ void virtio_init(VirtIODevice *vdev, uint16_t device_id,
size_t config_size)
bool virtio_legacy_allowed(VirtIODevice *vdev)
{
switch (vdev->device_id) {
+#ifdef CONFIG_VIRTIO_LEGACY
case VIRTIO_ID_NET:
case VIRTIO_ID_BLOCK:
case VIRTIO_ID_CONSOLE:
@@ -3513,6 +3516,7 @@ bool virtio_legacy_allowed(VirtIODevice *vdev)
case VIRTIO_ID_RPROC_SERIAL:
case VIRTIO_ID_CAIF:
return true;
+#endif
default:
return false;
}
@@ -4014,8 +4018,10 @@ static const Property virtio_properties[] = {
DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features),
DEFINE_PROP_BOOL("use-started", VirtIODevice, use_started, true),
DEFINE_PROP_BOOL("use-disabled-flag", VirtIODevice, use_disabled_flag,
true),
+#ifdef CONFIG_VIRTIO_LEGACY
DEFINE_PROP_BOOL("x-disable-legacy-check", VirtIODevice,
disable_legacy_check, false),
+#endif
};
static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
@@ -4151,7 +4157,9 @@ static void virtio_device_class_init(ObjectClass *klass,
const void *data)
vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl;
vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl;
+#ifdef CONFIG_VIRTIO_LEGACY
vdc->legacy_features |= VIRTIO_LEGACY_FEATURES;
+#endif
}
bool virtio_device_ioeventfd_enabled(VirtIODevice *vdev)
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 5e951675c60..d01fcb9fd1a 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -39,6 +39,7 @@
#if !defined(CONFIG_USER_ONLY)
#include "hw/loader.h"
#include "hw/boards.h"
+#include CONFIG_DEVICES
#ifdef CONFIG_TCG
#include "hw/intc/armv7m_nvic.h"
#endif /* CONFIG_TCG */
@@ -1130,6 +1131,7 @@ static void arm_cpu_kvm_set_irq(void *opaque, int irq,
int level)
#endif
}
+#ifdef CONFIG_VIRTIO_LEGACY
static bool arm_cpu_virtio_is_big_endian(CPUState *cs)
{
ARMCPU *cpu = ARM_CPU(cs);
@@ -1138,6 +1140,7 @@ static bool arm_cpu_virtio_is_big_endian(CPUState *cs)
cpu_synchronize_state(cs);
return arm_cpu_data_is_big_endian(env);
}
+#endif
#ifdef CONFIG_TCG
bool arm_cpu_exec_halt(CPUState *cs)
@@ -2681,7 +2684,9 @@ static const struct SysemuCPUOps arm_sysemu_ops = {
.asidx_from_attrs = arm_asidx_from_attrs,
.write_elf32_note = arm_cpu_write_elf32_note,
.write_elf64_note = arm_cpu_write_elf64_note,
+#ifdef CONFIG_VIRTIO_LEGACY
.virtio_is_big_endian = arm_cpu_virtio_is_big_endian,
+#endif
.legacy_vmsd = &vmstate_arm_cpu,
};
#endif
diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index b0973b6df95..4b6c347bda8 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -50,6 +50,7 @@
#include "hw/boards.h"
#include "hw/intc/intc.h"
#include "kvm_ppc.h"
+#include CONFIG_DEVICES
#endif
#include "cpu_init.h"
@@ -7352,12 +7353,14 @@ static void ppc_cpu_reset_hold(Object *obj, ResetType
type)
#ifndef CONFIG_USER_ONLY
+#ifdef CONFIG_VIRTIO_LEGACY
static bool ppc_cpu_is_big_endian(CPUState *cs)
{
cpu_synchronize_state(cs);
return !FIELD_EX64(cpu_env(cs)->msr, MSR, LE);
}
+#endif
static bool ppc_get_irq_stats(InterruptStatsProvider *obj,
uint64_t **irq_counts, unsigned int *nb_irqs)
@@ -7470,7 +7473,9 @@ static const struct SysemuCPUOps ppc_sysemu_ops = {
.get_phys_page_debug = ppc_cpu_get_phys_page_debug,
.write_elf32_note = ppc32_cpu_write_elf32_note,
.write_elf64_note = ppc64_cpu_write_elf64_note,
+#ifdef CONFIG_VIRTIO_LEGACY
.virtio_is_big_endian = ppc_cpu_is_big_endian,
+#endif
.legacy_vmsd = &vmstate_ppc_cpu,
};
#endif
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index 7648a2d68da..314185f0016 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -1,6 +1,11 @@
config VIRTIO
bool
+config VIRTIO_LEGACY
+ bool
+ default y
+ depends on VIRTIO
+
config VIRTIO_RNG
bool
default y
--
2.47.1
