| Message ID | 20250102211800.79235-2-philmd@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | QOM: container_get() removal | expand |
On Thu, Jan 02, 2025 at 10:17:53PM +0100, Philippe Mathieu-Daudé wrote: > When a QDev instance is realized, qdev_get_machine() ends up called. > In the next commit, qdev_get_machine() will require a "machine" > container to be always present. To satisfy this QOM containers design, > Implement qdev_create_fake_machine() which creates a fake "machine" > container for user emulation. > > On system emulation, qemu_create_machine() is called from qemu_init(). > For user emulation, since the TCG accelerator always calls > tcg_init_machine(), we use it to hook our fake machine creation. > > Suggested-by: Peter Xu <peterx@redhat.com> > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Acked-by: Peter Xu <peterx@redhat.com>
On 1/2/25 13:17, Philippe Mathieu-Daudé wrote: > When a QDev instance is realized, qdev_get_machine() ends up called. > In the next commit, qdev_get_machine() will require a "machine" > container to be always present. To satisfy this QOM containers design, > Implement qdev_create_fake_machine() which creates a fake "machine" > container for user emulation. > > On system emulation, qemu_create_machine() is called from qemu_init(). > For user emulation, since the TCG accelerator always calls > tcg_init_machine(), we use it to hook our fake machine creation. > > Suggested-by: Peter Xu <peterx@redhat.com> > Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> > --- > include/hw/qdev-core.h | 10 ++++++++++ > accel/tcg/tcg-all.c | 8 +++++++- > hw/core/qdev-user.c | 21 +++++++++++++++++++++ > hw/core/meson.build | 1 + > 4 files changed, 39 insertions(+), 1 deletion(-) > create mode 100644 hw/core/qdev-user.c > > diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h > index e6ef80b7fd0..b83b1439968 100644 > --- a/include/hw/qdev-core.h > +++ b/include/hw/qdev-core.h > @@ -1027,6 +1027,16 @@ const char *qdev_fw_name(DeviceState *dev); > void qdev_assert_realized_properly(void); > Object *qdev_get_machine(void); > > +/** > + * qdev_create_fake_machine(): Create a fake machine container. > + * > + * .. note:: > + * This function is a kludge for user emulation (USER_ONLY) > + * because when thread (TYPE_CPU) are realized, qdev_realize() > + * access a machine container. > + */ > +Object *qdev_create_fake_machine(void); > + > /** > * qdev_get_human_name() - Return a human-readable name for a device > * @dev: The device. Must be a valid and non-NULL pointer. > diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c > index c2565758876..95adaacee82 100644 > --- a/accel/tcg/tcg-all.c > +++ b/accel/tcg/tcg-all.c > @@ -35,7 +35,9 @@ > #include "qemu/atomic.h" > #include "qapi/qapi-builtin-visit.h" > #include "qemu/units.h" > -#if !defined(CONFIG_USER_ONLY) > +#if defined(CONFIG_USER_ONLY) > +#include "hw/qdev-core.h" > +#else > #include "hw/boards.h" > #endif > #include "internal-common.h" > @@ -124,6 +126,10 @@ static int tcg_init_machine(MachineState *ms) > tcg_prologue_init(); > #endif > > +#ifdef CONFIG_USER_ONLY > + qdev_create_fake_machine(); > +#endif No need to return the fake machine, it seems. With that, Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
On 3/1/25 15:24, Richard Henderson wrote: > On 1/2/25 13:17, Philippe Mathieu-Daudé wrote: >> When a QDev instance is realized, qdev_get_machine() ends up called. >> In the next commit, qdev_get_machine() will require a "machine" >> container to be always present. To satisfy this QOM containers design, >> Implement qdev_create_fake_machine() which creates a fake "machine" >> container for user emulation. >> >> On system emulation, qemu_create_machine() is called from qemu_init(). >> For user emulation, since the TCG accelerator always calls >> tcg_init_machine(), we use it to hook our fake machine creation. >> >> Suggested-by: Peter Xu <peterx@redhat.com> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> >> --- >> include/hw/qdev-core.h | 10 ++++++++++ >> accel/tcg/tcg-all.c | 8 +++++++- >> hw/core/qdev-user.c | 21 +++++++++++++++++++++ >> hw/core/meson.build | 1 + >> 4 files changed, 39 insertions(+), 1 deletion(-) >> create mode 100644 hw/core/qdev-user.c >> >> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h >> index e6ef80b7fd0..b83b1439968 100644 >> --- a/include/hw/qdev-core.h >> +++ b/include/hw/qdev-core.h >> @@ -1027,6 +1027,16 @@ const char *qdev_fw_name(DeviceState *dev); >> void qdev_assert_realized_properly(void); >> Object *qdev_get_machine(void); >> +/** >> + * qdev_create_fake_machine(): Create a fake machine container. >> + * >> + * .. note:: >> + * This function is a kludge for user emulation (USER_ONLY) >> + * because when thread (TYPE_CPU) are realized, qdev_realize() >> + * access a machine container. >> + */ >> +Object *qdev_create_fake_machine(void); >> + >> /** >> * qdev_get_human_name() - Return a human-readable name for a device >> * @dev: The device. Must be a valid and non-NULL pointer. >> diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c >> index c2565758876..95adaacee82 100644 >> --- a/accel/tcg/tcg-all.c >> +++ b/accel/tcg/tcg-all.c >> @@ -35,7 +35,9 @@ >> #include "qemu/atomic.h" >> #include "qapi/qapi-builtin-visit.h" >> #include "qemu/units.h" >> -#if !defined(CONFIG_USER_ONLY) >> +#if defined(CONFIG_USER_ONLY) >> +#include "hw/qdev-core.h" >> +#else >> #include "hw/boards.h" >> #endif >> #include "internal-common.h" >> @@ -124,6 +126,10 @@ static int tcg_init_machine(MachineState *ms) >> tcg_prologue_init(); >> #endif >> +#ifdef CONFIG_USER_ONLY >> + qdev_create_fake_machine(); >> +#endif > > No need to return the fake machine, it seems. My first reasoning was about avoiding ASan leak warnings, planning to release that container on exit(), but I'm clearly over-engineering what is meant to be a kludge. > With that, > > Reviewed-by: Richard Henderson <richard.henderson@linaro.org> I'll remove and merge directly, thanks!
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index e6ef80b7fd0..b83b1439968 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -1027,6 +1027,16 @@ const char *qdev_fw_name(DeviceState *dev); void qdev_assert_realized_properly(void); Object *qdev_get_machine(void); +/** + * qdev_create_fake_machine(): Create a fake machine container. + * + * .. note:: + * This function is a kludge for user emulation (USER_ONLY) + * because when thread (TYPE_CPU) are realized, qdev_realize() + * access a machine container. + */ +Object *qdev_create_fake_machine(void); + /** * qdev_get_human_name() - Return a human-readable name for a device * @dev: The device. Must be a valid and non-NULL pointer. diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c index c2565758876..95adaacee82 100644 --- a/accel/tcg/tcg-all.c +++ b/accel/tcg/tcg-all.c @@ -35,7 +35,9 @@ #include "qemu/atomic.h" #include "qapi/qapi-builtin-visit.h" #include "qemu/units.h" -#if !defined(CONFIG_USER_ONLY) +#if defined(CONFIG_USER_ONLY) +#include "hw/qdev-core.h" +#else #include "hw/boards.h" #endif #include "internal-common.h" @@ -124,6 +126,10 @@ static int tcg_init_machine(MachineState *ms) tcg_prologue_init(); #endif +#ifdef CONFIG_USER_ONLY + qdev_create_fake_machine(); +#endif + return 0; } diff --git a/hw/core/qdev-user.c b/hw/core/qdev-user.c new file mode 100644 index 00000000000..f816340db5a --- /dev/null +++ b/hw/core/qdev-user.c @@ -0,0 +1,21 @@ +/* + * QDev helpers specific to user emulation. + * + * Copyright 2025 Linaro, Ltd. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ +#include "qemu/osdep.h" +#include "qom/object.h" +#include "hw/qdev-core.h" + +Object *qdev_create_fake_machine(void) +{ + Object *fake_machine_obj; + + fake_machine_obj = object_property_add_new_container(object_get_root(), + "machine"); + object_property_add_new_container(fake_machine_obj, "unattached"); + + return fake_machine_obj; +} diff --git a/hw/core/meson.build b/hw/core/meson.build index ce9dfa3f4bf..65a1698ed1f 100644 --- a/hw/core/meson.build +++ b/hw/core/meson.build @@ -46,3 +46,4 @@ system_ss.add(files( 'vm-change-state-handler.c', 'clock-vmstate.c', )) +user_ss.add(files('qdev-user.c'))
When a QDev instance is realized, qdev_get_machine() ends up called. In the next commit, qdev_get_machine() will require a "machine" container to be always present. To satisfy this QOM containers design, Implement qdev_create_fake_machine() which creates a fake "machine" container for user emulation. On system emulation, qemu_create_machine() is called from qemu_init(). For user emulation, since the TCG accelerator always calls tcg_init_machine(), we use it to hook our fake machine creation. Suggested-by: Peter Xu <peterx@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> --- include/hw/qdev-core.h | 10 ++++++++++ accel/tcg/tcg-all.c | 8 +++++++- hw/core/qdev-user.c | 21 +++++++++++++++++++++ hw/core/meson.build | 1 + 4 files changed, 39 insertions(+), 1 deletion(-) create mode 100644 hw/core/qdev-user.c