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Re: [Qemu-devel] [PATCH 07/10] pci: introduce pci bus pre reset
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH 07/10] pci: introduce pci bus pre reset |
Date: |
Wed, 17 Feb 2016 17:52:04 +0200 |
On Wed, Feb 17, 2016 at 06:43:51PM +0800, Cao jin wrote:
> From: Chen Fan <address@hidden>
>
> avoid repeat bus reset, here introduce a sequence ID for each time
> bus hot reset, so each vfio device could know whether they've already
> been reset for that sequence ID.
>
> Signed-off-by: Chen Fan <address@hidden>
If the assumption that vfio functions are combined
in the same way as on the host, then this is not needed:
just reset when function 0 is reset.
I suggest we do it this way at stage one.
Add more checks when the functionality is in place.
> ---
> hw/core/qdev.c | 4 ++--
> hw/pci/pci.c | 25 +++++++++++++++++++++++++
> hw/pci/pci_bridge.c | 5 ++++-
> include/hw/pci/pci_bus.h | 4 ++++
> include/hw/qdev-core.h | 3 +++
> 5 files changed, 38 insertions(+), 3 deletions(-)
>
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 779de2b..e36fa07 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -304,14 +304,14 @@ void qdev_unplug(DeviceState *dev, Error **errp)
> }
> }
>
> -static int qdev_reset_one(DeviceState *dev, void *opaque)
> +int qdev_reset_one(DeviceState *dev, void *opaque)
> {
> device_reset(dev);
>
> return 0;
> }
>
> -static int qbus_reset_one(BusState *bus, void *opaque)
> +int qbus_reset_one(BusState *bus, void *opaque)
> {
> BusClass *bc = BUS_GET_CLASS(bus);
> if (bc->reset) {
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index e41925e..ff978bc 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -258,6 +258,29 @@ void pci_device_reset(PCIDevice *dev)
> pci_do_device_reset(dev);
> }
>
> +int pcibus_pre_reset(BusState *qbus, void *opaque)
> +{
> + BusState *bus = (BusState *)opaque;
> + PCIBus *pci_bus = DO_UPCAST(PCIBus, qbus, qbus);
> + static unsigned int reset_seqid;
> +
> + /*
> + * To distinguish the different reset times, we
> + * recalculate the global reset seqid with a given bus.
> + */
> + if (qbus == bus) {
> + reset_seqid++;
> + if (!reset_seqid) {
> + reset_seqid = 1;
> + }
> + }
> +
> + pci_bus->bus_in_reset = true;
> + pci_bus->reset_seqid = reset_seqid;
> +
> + return 0;
> +}
> +
> /*
> * Trigger pci bus reset under a given bus.
> * Called via qbus_reset_all on RST# assert, after the devices
> @@ -277,6 +300,8 @@ static void pcibus_reset(BusState *qbus)
> for (i = 0; i < bus->nirq; i++) {
> assert(bus->irq_count[i] == 0);
> }
> +
> + bus->bus_in_reset = false;
> }
>
> static void pci_host_bus_register(PCIBus *bus, DeviceState *parent)
> diff --git a/hw/pci/pci_bridge.c b/hw/pci/pci_bridge.c
> index 7eab9d5..6c35171 100644
> --- a/hw/pci/pci_bridge.c
> +++ b/hw/pci/pci_bridge.c
> @@ -269,7 +269,10 @@ void pci_bridge_write_config(PCIDevice *d,
> newctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
> if (~oldctl & newctl & PCI_BRIDGE_CTL_BUS_RESET) {
> /* Trigger hot reset on 0->1 transition. */
> - qbus_reset_all(&s->sec_bus.qbus);
> + qbus_walk_children(&s->sec_bus.qbus, NULL,
> + pcibus_pre_reset,
> + qdev_reset_one,
> + qbus_reset_one, &s->sec_bus.qbus);
> }
> }
>
> diff --git a/include/hw/pci/pci_bus.h b/include/hw/pci/pci_bus.h
> index 7812fa9..9dd2d6c 100644
> --- a/include/hw/pci/pci_bus.h
> +++ b/include/hw/pci/pci_bus.h
> @@ -40,11 +40,15 @@ struct PCIBus {
> int nirq;
> int *irq_count;
>
> + bool bus_in_reset;
> + uint32_t reset_seqid;
> +
> NotifierWithReturnList hotplug_notifiers;
> };
>
> void pci_bus_add_hotplug_notifier(PCIBus *bus, NotifierWithReturn *notify);
> void pci_bus_remove_hotplug_notifier(NotifierWithReturn *notify);
> +int pcibus_pre_reset(BusState *qbus, void *opaque);
>
> typedef struct PCIBridgeWindows PCIBridgeWindows;
>
> diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
> index abcdee8..3d71c17 100644
> --- a/include/hw/qdev-core.h
> +++ b/include/hw/qdev-core.h
> @@ -401,4 +401,7 @@ static inline bool qbus_is_hotpluggable(BusState *bus)
> void device_listener_register(DeviceListener *listener);
> void device_listener_unregister(DeviceListener *listener);
>
> +int qdev_reset_one(DeviceState *dev, void *opaque);
> +int qbus_reset_one(BusState *bus, void *opaque);
> +
> #endif
> --
> 1.9.3
>
>
- [Qemu-devel] [PATCH 01/10] vfio: extract vfio_get_hot_reset_info as a single function, (continued)
- [Qemu-devel] [PATCH 01/10] vfio: extract vfio_get_hot_reset_info as a single function, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 02/10] vfio: squeeze out vfio_pci_do_hot_reset for support bus reset, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 03/10] vfio: add pcie extended capability support, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 04/10] vfio: add aer support for vfio device, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 05/10] vfio: add check host bus reset is support or not, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 06/10] add check reset mechanism when hotplug vfio device, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 08/10] vfio: introduce last reset sequence id, Cao jin, 2016/02/17
- [Qemu-devel] [PATCH 07/10] pci: introduce pci bus pre reset, Cao jin, 2016/02/17
- Re: [Qemu-devel] [PATCH 07/10] pci: introduce pci bus pre reset,
Michael S. Tsirkin <=
- [Qemu-devel] [PATCH 09/10] vfio-pci: pass the aer error to guest, Cao jin, 2016/02/17