| Message ID | 20221109170009.3498451-1-peter.maydell@linaro.org |
|---|---|
| Headers | show |
| Series | hw/input/ps2: Convert to 3-phase reset | expand |
On 09/11/2022 17:00, Peter Maydell wrote: > This patchset converts the ps2 keyboard and mouse devices to 3-phase > reset. The rationale here is that it would be nice to get rid of the > device_class_set_parent_reset() function, which is used by > legacy-reset subclasses which want to chain to their parent's reset > function. There aren't very many of these devices in total, and if we > convert them all to 3-phase reset they can use the 3-phase-reset > equivalent (resettable_class_set_parent_phases()). Eventually this > will then let us simplify the transitional code for handling old-style > device reset. > > This is one of a number of patchsets to do this that I'm planning to > write and send out over the next few weeks. It's all 8.0 material. > > thanks > -- PMM > > Peter Maydell (2): > hw/input/ps2: Convert TYPE_PS2_DEVICE to 3-phase reset > hw/input/ps2.c: Convert TYPE_PS2_{KBD,MOUSE}_DEVICE to 3-phase reset > > include/hw/input/ps2.h | 2 +- > hw/input/ps2.c | 45 +++++++++++++++++++++++++++++------------- > 2 files changed, 32 insertions(+), 15 deletions(-) I haven't used the new ResettableClass myself previously, however it seems to match the excellent documentation at https://qemu.readthedocs.io/en/latest/devel/reset.html so feel free to add my Acked-by tag. One part that did stand out to me in the docs is the part that reads "For now migration of a device or bus in reset is not supported. Care must be taken not to delay resettable_release_reset() after its resettable_assert_reset() counterpart". Is this still a valid concern and something we need to think about? I'm thinking about if a guest triggers a SCSI bus or PCI bus reset for example. ATB, Mark.
On Thu, 10 Nov 2022 at 10:36, Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> wrote: > I haven't used the new ResettableClass myself previously, however it seems to match > the excellent documentation at https://qemu.readthedocs.io/en/latest/devel/reset.html > so feel free to add my Acked-by tag. > > One part that did stand out to me in the docs is the part that reads "For now > migration of a device or bus in reset is not supported. Care must be taken not to > delay resettable_release_reset() after its resettable_assert_reset() counterpart". Is > this still a valid concern and something we need to think about? I'm thinking about > if a guest triggers a SCSI bus or PCI bus reset for example. That only matters if there's a way for the guest to hold the device in reset, as opposed to resetting it as a point event. This is theoretically possible to do with the new API, and was simply impossible with the old API because with the old one reset was always a one-shot point event. thanks -- PMM
On 10/11/2022 11:22, Peter Maydell wrote: > On Thu, 10 Nov 2022 at 10:36, Mark Cave-Ayland > <mark.cave-ayland@ilande.co.uk> wrote: >> I haven't used the new ResettableClass myself previously, however it seems to match >> the excellent documentation at https://qemu.readthedocs.io/en/latest/devel/reset.html >> so feel free to add my Acked-by tag. >> >> One part that did stand out to me in the docs is the part that reads "For now >> migration of a device or bus in reset is not supported. Care must be taken not to >> delay resettable_release_reset() after its resettable_assert_reset() counterpart". Is >> this still a valid concern and something we need to think about? I'm thinking about >> if a guest triggers a SCSI bus or PCI bus reset for example. > > That only matters if there's a way for the guest to hold the device > in reset, as opposed to resetting it as a point event. This is > theoretically possible to do with the new API, and was simply > impossible with the old API because with the old one reset was > always a one-shot point event. I see, thanks. And the documentation confirms that resettable_reset() is an assert immediately followed by a release so that shouldn't be an issue for device_cold_reset() and bus_cold_reset() calling the new Resettable inteface. ATB, Mark.
On Wed, 9 Nov 2022 at 17:00, Peter Maydell <peter.maydell@linaro.org> wrote: > > This patchset converts the ps2 keyboard and mouse devices to 3-phase > reset. The rationale here is that it would be nice to get rid of the > device_class_set_parent_reset() function, which is used by > legacy-reset subclasses which want to chain to their parent's reset > function. There aren't very many of these devices in total, and if we > convert them all to 3-phase reset they can use the 3-phase-reset > equivalent (resettable_class_set_parent_phases()). Eventually this > will then let us simplify the transitional code for handling old-style > device reset. I plan to pick these up and send them in a pullreq together with various other reset-related patches of mine, unless you'd prefer them to go in some other way. thanks -- PMM
This patchset converts the ps2 keyboard and mouse devices to 3-phase reset. The rationale here is that it would be nice to get rid of the device_class_set_parent_reset() function, which is used by legacy-reset subclasses which want to chain to their parent's reset function. There aren't very many of these devices in total, and if we convert them all to 3-phase reset they can use the 3-phase-reset equivalent (resettable_class_set_parent_phases()). Eventually this will then let us simplify the transitional code for handling old-style device reset. This is one of a number of patchsets to do this that I'm planning to write and send out over the next few weeks. It's all 8.0 material. thanks -- PMM Peter Maydell (2): hw/input/ps2: Convert TYPE_PS2_DEVICE to 3-phase reset hw/input/ps2.c: Convert TYPE_PS2_{KBD,MOUSE}_DEVICE to 3-phase reset include/hw/input/ps2.h | 2 +- hw/input/ps2.c | 45 +++++++++++++++++++++++++++++------------- 2 files changed, 32 insertions(+), 15 deletions(-)