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Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing at
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command |
Date: |
Mon, 25 Oct 2010 06:15:37 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Mon, Oct 25, 2010 at 12:29:57PM +0900, Isaku Yamahata wrote:
> On Fri, Oct 22, 2010 at 04:38:49PM +0200, Michael S. Tsirkin wrote:
> > On Fri, Oct 22, 2010 at 01:35:47PM +0200, Markus Armbruster wrote:
> > > "Michael S. Tsirkin" <address@hidden> writes:
> > >
> > > > On Wed, Oct 20, 2010 at 05:18:56PM +0900, Isaku Yamahata wrote:
> > > >> glue pcie_push_attention_button command.
> > > >>
> > > >> Signed-off-by: Isaku Yamahata <address@hidden>
> > > >
> > > > So as a high level command, I think we need to
> > > > think about how to tie this into pci_add/pci_del.
> > > > Right?
> > > [...]
> > >
> > > Do we have consensus how our set of commands for hot plug should look
> > > like? We talked about it, but did we reach consensus? If yes, did we
> > > write it down somewhere?
> >
> > I think for simple things yes:
> > - command to send hotplug notification to the guest
> > - command to immediately add/remove the device
> > - event to notify about guest ack
> > - way to poll status: did guest ack last command?
>
> I'm not sure about guest ack. Let me check my understanding.
Your understanding is correct.
> The current qemu pci hot plug has its own hot plug controler,
> PIIX4_PM, which relies on ACPI.
>
> - command to add the device into the slot
> This corresponds to physically inserting the device into the slot.
> - qemu pci hot plug case: device_add/pci_add command.
> The qemu pci hot plug controller, PIIX4_PM, detects the insertion,
> then notify the guest OS of the event via ACPI, _L01.
> The guest OS would start to probe the device.
>
> - pci express native hot plug case: device_add/pci_add command.
> The pcie hot plug controller detects the the insertion,
> then notify the guest OS of the event via interrupt.
> The guest OS would start to probe the device.
>
> - command to remove the device from the slot
> This corresponds to physically removing the device from the slot.
> - qemu pci hot plug case: No corresponding command.
> There is no way to remove the pci card forcibly from the slot.
>
> - pci express native hot plug case: device_del/pci_del
> After the removal of the card, the hot plug controller notifies
> the guest OS via interrupt.
>
> - command to send hotplug notification to the guest
> command to push attention button.
> This corresponds to pushing the button near the slot.
> - qemu pci hot plug case: device_del/pci_del command
> Maybe the button is called an eject button.
> When the button is pushed, the hot plug controller notifies
> the guest OS via ACPI, _L01.
> Then, guest OS reacts the event by calling ACPI \_SB.PCI0.S<n>._EJ0
> method. It program the hot plug controller to eject the device
> in the given slot. As a result, the device is removed from the slot.
> If the guest OS doesn't call _EJ0 (nor programs the controller directly),
> the device stays there.
> There is no way to remove the pci card without the guest OS
> intervention.
>
> - pci express native hot plug case:
> pcie_push_attention_button command with my patch series.
> The hot plug controller raise the interrupt to the guest OS.
> There is no specified action from the OS.
Right. So what is suggested is that we have
A. a single command to push the attention button
B. a single command to remove pci card without guest OS interaction
C. a way to interact with the guest
management tools or human monitor will be able to tie A,B,C together
in various interesting ways
What I am also saying is that the same command should be able
to work for pci and express I think.
> - a way to get the slot status
> new command for QMP/HMP? or enhance info pci?
>
> - QMP event for qemu to notify the slot status change
> e.g. when LED status is changed, qmp event will be sent.
>
> > Existing ones will keep function:
> > - send notification and when acked remove device
> > - add device and send notification
> > These are useful for human monitor but maybe not
> > for management.
> >
> >
> > --
> > MST
> >
>
> --
> yamahata
- [Qemu-devel] [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, (continued)
- [Qemu-devel] [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Isaku Yamahata, 2010/10/20
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Markus Armbruster, 2010/10/22
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Michael S. Tsirkin, 2010/10/22
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Anthony Liguori, 2010/10/22
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Michael S. Tsirkin, 2010/10/25
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Isaku Yamahata, 2010/10/24
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command,
Michael S. Tsirkin <=
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Isaku Yamahata, 2010/10/25
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Michael S. Tsirkin, 2010/10/25
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Isaku Yamahata, 2010/10/25
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Michael S. Tsirkin, 2010/10/25
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Isaku Yamahata, 2010/10/26
- Re: [Qemu-devel] Re: [PATCH v6 07/12] pcie/hotplug: introduce pushing attention button command, Michael S. Tsirkin, 2010/10/27
[Qemu-devel] [PATCH v6 10/12] ioh3420: support aer, Isaku Yamahata, 2010/10/20
[Qemu-devel] [PATCH v6 06/12] x3130: pcie downstream port, Isaku Yamahata, 2010/10/20
[Qemu-devel] [PATCH v6 03/12] pcie port: define struct PCIEPort/PCIESlot and helper functions, Isaku Yamahata, 2010/10/20
[Qemu-devel] [PATCH v6 12/12] x3130/downstream: support aer., Isaku Yamahata, 2010/10/20