mirror of https://gitlab.com/qemu-project/qemu
58660bfa36
PCI device capable of SR-IOV support is a new, still-experimental feature with only a single working example of the Nvme device. This patch in an attempt to fix a double-free problem when a SR-IOV-capable Nvme device is hot-unplugged in the following scenario: Qemu CLI: --------- -device pcie-root-port,slot=0,id=rp0 -device nvme-subsys,id=subsys0 -device nvme,id=nvme0,bus=rp0,serial=deadbeef,subsys=subsys0,sriov_max_vfs=1,sriov_vq_flexible=2,sriov_vi_flexible=1 Guest OS: --------- sudo nvme virt-mgmt /dev/nvme0 -c 0 -r 1 -a 1 -n 0 sudo nvme virt-mgmt /dev/nvme0 -c 0 -r 0 -a 1 -n 0 echo 1 > /sys/bus/pci/devices/0000:01:00.0/reset sleep 1 echo 1 > /sys/bus/pci/devices/0000:01:00.0/sriov_numvfs nvme virt-mgmt /dev/nvme0 -c 1 -r 1 -a 8 -n 1 nvme virt-mgmt /dev/nvme0 -c 1 -r 0 -a 8 -n 2 nvme virt-mgmt /dev/nvme0 -c 1 -r 0 -a 9 -n 0 sleep 2 echo 01:00.1 > /sys/bus/pci/drivers/nvme/bind Qemu monitor: ------------- device_del nvme0 Explanation of the problem and the proposed solution: 1) The current SR-IOV implementation assumes it’s the PhysicalFunction that creates and deletes VirtualFunctions. 2) It’s a design decision (the Nvme device at least) for the VFs to be of the same class as PF. Effectively, they share the dc->hotpluggable value. 3) When a VF is created, it’s added as a child node to PF’s PCI bus slot. 4) Monitor/device_del triggers the ACPI mechanism. The implementation is not aware of SR/IOV and ejects PF’s PCI slot, directly unrealizing all hot-pluggable (!acpi_pcihp_pc_no_hotplug) children nodes. 5) VFs are unrealized directly, and it doesn’t work well with (1). SR/IOV structures are not updated, so when it’s PF’s turn to be unrealized, it works on stale pointers to already-deleted VFs. The proposed fix is to make the PCI ACPI code aware of SR/IOV. Signed-off-by: Łukasz Gieryk <lukasz.gieryk@linux.intel.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Klaus Jensen <k.jensen@samsung.com> |
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| .. | ||
| Kconfig | ||
| acpi-cpu-hotplug-stub.c | ||
| acpi-mem-hotplug-stub.c | ||
| acpi-nvdimm-stub.c | ||
| acpi-pci-hotplug-stub.c | ||
| acpi-stub.c | ||
| acpi-x86-stub.c | ||
| acpi_interface.c | ||
| aml-build-stub.c | ||
| aml-build.c | ||
| bios-linker-loader.c | ||
| core.c | ||
| cpu.c | ||
| cpu_hotplug.c | ||
| cxl-stub.c | ||
| cxl.c | ||
| erst.c | ||
| generic_event_device.c | ||
| ghes-stub.c | ||
| ghes.c | ||
| hmat.c | ||
| hmat.h | ||
| ich9.c | ||
| ipmi-stub.c | ||
| ipmi.c | ||
| memory_hotplug.c | ||
| meson.build | ||
| nvdimm.c | ||
| pci.c | ||
| pcihp.c | ||
| piix4.c | ||
| tco.c | ||
| tpm.c | ||
| trace-events | ||
| trace.h | ||
| utils.c | ||
| viot.c | ||
| viot.h | ||
| vmgenid.c | ||