Hi Eduardo,
On 24.11.2017 14:46, Eduardo Otubo wrote:
> v3:
> * Removed all unecessary local_err
> * Change return of isa_bus_dma() and DMA_init() from void to int8_t,
> returning -EBUSY on error and 0 on success
> * Added qdev_cleanup_nofail() in case isa_bus_dma() returns error. The
> cleanup looks safe, but please review if I didn't miss any detail
>
> v2:
> * Removed user_creatable=false and replaced by error handling using
> Error **errp and error_propagate();
Version changelog should go below the "---" separator, otherwise it will
be included in the git changelog as well, which is kind of ugly.
> QEMU fails when used with the following command line:
>
> ./ppc64-softmmu/qemu-system-ppc64 -S -machine 40p,accel=tcg -device i82374
> qemu-system-ppc64: hw/isa/isa-bus.c:110: isa_bus_dma: Assertion
> `!bus->dma[0] && !bus->dma[1]' failed.
> Aborted (core dumped)
>
> The 40p machine type already created the device i82374. If specified in the
> command line, it will try to create it again, hence generating the error. The
> function isa_bus_dma() isn't supposed to be called twice for the same bus. One
> way to avoid this problem is to set user_creatable=false.
You don't do that user_creatable=false here anymore, so please remove it
from the description.
> A possible fix in a near future would be making
> isa_bus_dma()/DMA_init()/i82374_realize() return an error instead of asserting
> as well.
You should rephrase that sentence as well.
> Signed-off-by: Eduardo Otubo <ot...@redhat.com>
> ---
> hw/core/qdev.c | 16 ++++++++++++++++
> hw/dma/i82374.c | 13 +++++++------
> hw/dma/i8257.c | 38 ++++++++++++++++++++++----------------
> hw/isa/isa-bus.c | 8 ++++++--
> include/hw/isa/isa.h | 4 ++--
> include/hw/qdev-core.h | 1 +
> 6 files changed, 54 insertions(+), 26 deletions(-)
>
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 606ab53c42..0ef03ee461 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -344,6 +344,22 @@ void qdev_init_nofail(DeviceState *dev)
> object_unref(OBJECT(dev));
> }
>
> +void qdev_cleanup_nofail(DeviceState *dev)
> +{
> + Error *err = NULL;
> +
> + assert(dev->realized);
> +
> + object_ref(OBJECT(dev));
> + object_property_set_bool(OBJECT(dev), false, "realized", &err);
> + if (err) {
> + error_reportf_err(err, "Clean up of device %s failed: ",
> + object_get_typename(OBJECT(dev)));
> + exit(1);
> + }
> + object_unref(OBJECT(dev));
> +}
> +
> void qdev_machine_creation_done(void)
> {
> /*
> diff --git a/hw/dma/i82374.c b/hw/dma/i82374.c
> index 6c0f975df0..9b792890b2 100644
> --- a/hw/dma/i82374.c
> +++ b/hw/dma/i82374.c
> @@ -24,6 +24,7 @@
>
> #include "qemu/osdep.h"
> #include "hw/isa/isa.h"
> +#include "qapi/error.h"
>
> #define TYPE_I82374 "i82374"
> #define I82374(obj) OBJECT_CHECK(I82374State, (obj), TYPE_I82374)
> @@ -118,13 +119,13 @@ static void i82374_realize(DeviceState *dev, Error
> **errp)
> {
> I82374State *s = I82374(dev);
>
> - portio_list_init(&s->port_list, OBJECT(s), i82374_portio_list, s,
> - "i82374");
> - portio_list_add(&s->port_list, isa_address_space_io(&s->parent_obj),
> + if (DMA_init(isa_bus_from_device(ISA_DEVICE(dev)), 1, errp) == 0) {
I think I'd rather prefer if (DMA_init()) { return; } here ... but
that's just my personal taste.
> + portio_list_init(&s->port_list, OBJECT(s), i82374_portio_list, s,
> + "i82374");
> + portio_list_add(&s->port_list, isa_address_space_io(&s->parent_obj),
> s->iobase);
> -
> - DMA_init(isa_bus_from_device(ISA_DEVICE(dev)), 1);
> - memset(s->commands, 0, sizeof(s->commands));
> + memset(s->commands, 0, sizeof(s->commands));
> + }
> }
>
> static Property i82374_properties[] = {
> diff --git a/hw/dma/i8257.c b/hw/dma/i8257.c
> index bd23e893bf..7488e3dd12 100644
> --- a/hw/dma/i8257.c
> +++ b/hw/dma/i8257.c
> @@ -622,26 +622,32 @@ static void i8257_register_types(void)
>
> type_init(i8257_register_types)
>
> -void DMA_init(ISABus *bus, int high_page_enable)
> +int8_t DMA_init(ISABus *bus, int high_page_enable, Error **errp)
Why int8_t ? Error codes are normally propagated as normal "int", and in
the very worst case -EBUSY might even not fit anymore into a normal
int8_t on some systems...
> {
> ISADevice *isa1, *isa2;
> - DeviceState *d;
> + DeviceState *d1, *d2;
>
> isa1 = isa_create(bus, TYPE_I8257);
> - d = DEVICE(isa1);
> - qdev_prop_set_int32(d, "base", 0x00);
> - qdev_prop_set_int32(d, "page-base", 0x80);
> - qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x480 : -1);
> - qdev_prop_set_int32(d, "dshift", 0);
> - qdev_init_nofail(d);
> + d1 = DEVICE(isa1);
> + qdev_prop_set_int32(d1, "base", 0x00);
> + qdev_prop_set_int32(d1, "page-base", 0x80);
> + qdev_prop_set_int32(d1, "pageh-base", high_page_enable ? 0x480 : -1);
> + qdev_prop_set_int32(d1, "dshift", 0);
> + qdev_init_nofail(d1);
>
> isa2 = isa_create(bus, TYPE_I8257);
> - d = DEVICE(isa2);
> - qdev_prop_set_int32(d, "base", 0xc0);
> - qdev_prop_set_int32(d, "page-base", 0x88);
> - qdev_prop_set_int32(d, "pageh-base", high_page_enable ? 0x488 : -1);
> - qdev_prop_set_int32(d, "dshift", 1);
> - qdev_init_nofail(d);
> -
> - isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2));
> + d2 = DEVICE(isa2);
> + qdev_prop_set_int32(d2, "base", 0xc0);
> + qdev_prop_set_int32(d2, "page-base", 0x88);
> + qdev_prop_set_int32(d2, "pageh-base", high_page_enable ? 0x488 : -1);
> + qdev_prop_set_int32(d2, "dshift", 1);
> + qdev_init_nofail(d2);
> +
> + if (isa_bus_dma(bus, ISADMA(isa1), ISADMA(isa2), errp) < 0) {
> + qdev_cleanup_nofail(d1);
> + qdev_cleanup_nofail(d2);
> + return -EBUSY;
> + }
> +
> + return 0;
> }
> diff --git a/hw/isa/isa-bus.c b/hw/isa/isa-bus.c
> index 348e0eab9d..4781dddaf9 100644
> --- a/hw/isa/isa-bus.c
> +++ b/hw/isa/isa-bus.c
> @@ -104,12 +104,16 @@ void isa_connect_gpio_out(ISADevice *isadev, int
> gpioirq, int isairq)
> qdev_connect_gpio_out(DEVICE(isadev), gpioirq, irq);
> }
>
> -void isa_bus_dma(ISABus *bus, IsaDma *dma8, IsaDma *dma16)
> +int8_t isa_bus_dma(ISABus *bus, IsaDma *dma8, IsaDma *dma16, Error **errp)
dito - this should be "int", not "int8_t".
> {
> assert(bus && dma8 && dma16);
> - assert(!bus->dma[0] && !bus->dma[1]);
> + if (bus->dma[0] || bus->dma[1]) {
> + error_setg(errp, "DMA already initialized on ISA bus");
> + return -EBUSY;
> + }
> bus->dma[0] = dma8;
> bus->dma[1] = dma16;
> + return 0;
> }
>
Thomas
