RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=737720#c8 (dmesg and DSDT were attached in bz)
Boot up a Linux VM with 8 pci block devices which are the 8 functions in one pci slot. | # qemu-kvm ... | -drive file=images/u0,if=none,id=drv0,format=qcow2,cache=none \ | -device virtio-blk-pci,drive=drv0,id=v0,multifunction=on,addr=0x03.0 \ | .... | -drive file=images/u7,if=none,id=drv7,format=qcow2,cache=none \ | -device virtio-blk-pci,drive=drv7,id=v7,multifunction=on,addr=0x03.7 \
Check devices in guest. | vm)# ls /dev/vd* | vda vdb vdc vde vdf vdg vdh | vm)# lspci |grep block | 00:03.0 SCSI storage controller: Red Hat, Inc Virtio block device | ... | 00:03.7 SCSI storage controller: Red Hat, Inc Virtio block device |
Func1~7 still exist in guest after hot-removing the whole slot by qemu monitor cmd. | vm)# lspci |grep block (00:03.0 disappeared) | 00:03.1 SCSI storage controller: Red Hat, Inc Virtio block device (rev ff) | ... | 00:03.7 SCSI storage controller: Red Hat, Inc Virtio block device (rev ff) | vm)# ls /dev/vd* (vda disappeared) | vdb vdc vde vdf vdg vdh | vm)# mkfs /dev/vdb | INFO: task mkfs.ext2:1784 blocked for more than 120 seconds.
We process pci slot as a whole device, in seabios only defines one device for a slot in ACPI DSDT table, then there is only one entry (for func#0) would be added into 'slot->funcs' list. When we release the whole slot, only the entry in 'slot->funcs' will be cleaned, so func#1~7 could not be cleaned from system.
| 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 is only executed 1 time(for func#0) | __pci_remove_bus_device(pdev); | pci_dev_put(pdev);
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().
Hotpluging multifunc of guests(WinXp/Win7) is fine.
--- v1 thread: http://marc.info/?t=131597601700003&r=1&w=2
Changes from v1: - rebase patch to latest linux.git - remove unnecessary multiplefunction check - rename 'i' to meaningful 'fn' - fix coding style
Signed-off-by: Amos Kong akong@redhat.com --- drivers/pci/hotplug/acpiphp_glue.c | 20 +++++++++++--------- 1 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index 806c44f..42f9bb9 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -887,6 +887,7 @@ 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 fn;
/* The slot will be enabled when func 0 is added, so check func 0 before disable the slot. */ @@ -902,16 +903,17 @@ 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); + for (fn = 0; fn < 8; fn++) { + pdev = pci_get_slot(bus, PCI_DEVFN(slot->device, fn)); + 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); } }