Re: [SeaBIOS] [PATCH] pci: clean all funcs when hot-removing multifunc device

[Amos Kong]

----- Original Message -----
> ----- Original Message -----
> > (2011/09/14 13:55), Amos Kong wrote:
> > > 'slot->funcs' is initialized in acpiphp_glue.c:register_slot()
> > > before
> > > hotpluging device, and only one entry(func 0) is added to it,
> > > no new entry will be added to the list when hotpluging devices to
> > > the slot.
> >
> > I guess your hotplug slot has only one device object (for func#0)
> > in ACPI Namespace (DSDT), and guess this is why there is only one
> > entry in the 'slot->funcs'. If so, what about adding device objects
> > for function 1-7 to ACPI Namespace? I think most of bare-metal
> > environments have such definition in ACPI Namespace. For example:
>
> Hi Kaneshige,
>
> I did some test, fix acpi tables can resolve this problem,
> then register_slot() will be executed for all funcs,
> and each func has a entry in slot->funcs.
> I will send a patch to seabios.

The size of bios.bin compiled from seabios
original: 128K
only apply patch1:  256K
only apply patch2:  128K

patch1: add 6 slot(only slot6 has 8 funcs) to the table
can hotplug/hot-remove a multifunc device to slot 6 successfully

patch2: add 31 slot(with 8 funcs) to the table
could not boot up guest.
I found there is a special process for large bios.bin in qemu,
problem maybe exist here, I'm driving into it...

qemu/hw/pc.c:
void pc_memory_init(...
    ....
    /* map the last 128KB of the BIOS in ISA space */
    isa_bios_size = bios_size;
    if (isa_bios_size > (128 * 1024))
        isa_bios_size = 128 * 1024;
> > Device (P2P) { // PCI to PCI bridge
> > Name (_ADR, ...) // PCI address
> > Name (_HPP, ...) // Hot Plug parameter
> > ...
> > Device (S0F0) { // For function 0
> > Name (_ADR, ...)
> > Name (_SUN, ...)
> > Method (_EJ0, ...)
> > }
> > Device (S0F1) { // For function 1
> > ...
> > }
> > ...
> > Device (S0F7) { // For function 7
> > ...
> > }
> > }
> >
> > Regards,
> > Kenji Kaneshige
> > > When we release the whole device, there is only one entry in the
> > > list,
> > > this causes func1~7 could not be released.
> > > I try to add entries for all hotpluged device in enable_device(),
> > > but
> > > it doesn't work, because 'slot->funcs' is used in many place which
> > > we only
> > > need to process func 0. This patch just try to clean all funcs in
> > > disable_device().
> > >
> > > drivers/pci/hotplug/acpiphp_glue.c:
> > > static int disable_device(struct acpiphp_slot *slot) {
> > >    list_for_each_entry(func,&slot->funcs, sibling) {
> > >    	pdev = pci_get_slot(slot->bridge->pci_bus,
> > >    	       PCI_DEVFN(slot->device, func->function));
> > >    	..clean code.. // those code can only be executed one time(func
> > >    	0)
> > >                  pci_remove_bus_device(pdev);
> > >
> > > pci_bus_add_device() is called for each func device in
> > > acpiphp_glue.c:enable_device().
> > > pci_remove_bus_device(pdev) is only called for func 0 in
> > > acpiphp_glue.c:disable_device().
> > >
> > > Boot up a KVM guest, hotplug a multifunc device(8 funcs), we can
> > > find it in the guest.
> > > @ ls /dev/vd*
> > >     vda vdb vdc vde vdf vdg vdh
> > > @ lspci
> > >     00:06.0 SCSI storage controller: Red Hat, Inc Virtio block
> > >     device
> > >     ...
> > >     00:06.7 SCSI storage controller: Red Hat, Inc Virtio block
> > >     device
> > >
> > > But func 1~7 still exist in guest after hot-removing the multifunc
> > > device through qemu monitor.
> > > @ lspci (00:06.0 disappeared)
> > >     00:06.1 SCSI storage controller: Red Hat, Inc Virtio block
> > >     device (rev ff)
> > >     ...
> > >     00:06.7 SCSI storage controller: Red Hat, Inc Virtio block
> > >     device (rev ff)
> > >                                                                       ^^^^^^^^
> > > @ ls /dev/vd*
> > >     vdb vdc vde vdf vdg vdh
> > > @ mkfs /dev/vdb
> > >     INFO: task mkfs.ext2:1784 blocked for more than 120 seconds.
> > >     (task hung)
> > >
> > > Hotpluging multifunc of WinXp is fine.
> > > Signed-off-by: Amos Kong
> > >
> > > drivers/pci/hotplug/acpiphp_glue.c | 27
> > >   ++++++++++++++++++---------
> > >   1 files changed, 18 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c
> > > b/drivers/pci/hotplug/acpiphp_glue.c
> > > index a70fa89..3b86d1a 100644
> > > --- a/drivers/pci/hotplug/acpiphp_glue.c
> > > +++ b/drivers/pci/hotplug/acpiphp_glue.c
> > > @@ -880,6 +880,8 @@ static int disable_device(struct acpiphp_slot
> > > *slot)
> > >   {
> > >    struct acpiphp_func *func;
> > >    struct pci_dev *pdev;
> > >
> > > struct pci_bus *bus = slot->bridge->pci_bus;
> > >
> > > int i, num = 1;
> > >
> > > /* is this slot already disabled? */
> > >  if (!(slot->flags& SLOT_ENABLED))
> > >
> > > @@ -893,16 +895,23 @@ static int disable_device(struct
> > > acpiphp_slot
> > > *slot)
> > >    		func->bridge = NULL;
> > >    	}
> > > pdev = pci_get_slot(slot->bridge->pci_bus,
> > > PCI_DEVFN(slot->device, func->function));
> > > if (pdev) {
> > > pci_stop_bus_device(pdev);
> > > if (pdev->subordinate) {
> > > disable_bridges(pdev->subordinate);
> > > pci_disable_device(pdev);
> > > pdev = pci_scan_single_device(bus,
> > > PCI_DEVFN(slot->device, 0));
> > > if (!pdev)
> > > goto err_exit;
> > > if (pdev->multifunction == 1)
> > > num = 8;
> > > for (i=0; i<num; i++) {
> > > pdev = pci_get_slot(bus, PCI_DEVFN(slot->device, i));
> > > if (pdev) {
> > > pci_stop_bus_device(pdev);
> > > if (pdev->subordinate) {
> > > disable_bridges(pdev->subordinate);
> > > pci_disable_device(pdev);
> > > }
> > > pci_remove_bus_device(pdev);
> > > pci_dev_put(pdev);
> > >   	}
> > > pci_remove_bus_device(pdev);
> > > pci_dev_put(pdev);
> > >   }
> > >  }