qemu/hw/pci-bridge
Michael S. Tsirkin 2841ab435b pcie: check that slt ctrl changed before deleting
During boot, linux would sometimes overwrites control of a powered off
slot before powering it on. Unfortunately QEMU interprets that as a
power off request and ejects the device.

For example:

/x86_64-softmmu/qemu-system-x86_64 -enable-kvm -S -machine q35  \
    -device pcie-root-port,id=pcie_root_port_0,slot=2,chassis=2,addr=0x2,bus=pcie.0 \
    -monitor stdio disk.qcow2
(qemu)device_add virtio-balloon-pci,id=balloon,bus=pcie_root_port_0
(qemu)cont

Balloon is deleted during guest boot.

To fix, save control beforehand and check that power
or led state actually change before ejecting.

Note: this is more a hack than a solution, ideally we'd
find a better way to detect ejects, or move away
from ejects completely and instead monitor whether
it's safe to delete device due to e.g. its power state.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Igor Mammedov <imammedo@redhat.com>
2019-07-01 09:17:30 -04:00
..
Kconfig kconfig: add dependencies on CONFIG_MSI_NONBROKEN 2019-03-18 09:39:57 +01:00
Makefile.objs apb: split simba PCI bridge into hw/pci-bridge/simba.c 2018-01-24 19:19:50 +00:00
dec.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
dec.h Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
gen_pcie_root_port.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
i82801b11.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
ioh3420.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
pci_bridge_dev.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
pci_expander_bridge.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
pcie_pci_bridge.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
pcie_root_port.c pcie: check that slt ctrl changed before deleting 2019-07-01 09:17:30 -04:00
simba.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00
xio3130_downstream.c pcie: check that slt ctrl changed before deleting 2019-07-01 09:17:30 -04:00
xio3130_upstream.c Include qemu/module.h where needed, drop it from qemu-common.h 2019-06-12 13:18:33 +02:00