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[Qemu-devel] [PATCH v2 0/1] vfio-pci: fix assert fail in host property i
From: |
Daniel Oram |
Subject: |
[Qemu-devel] [PATCH v2 0/1] vfio-pci: fix assert fail in host property if unused |
Date: |
Thu, 10 Nov 2016 12:42:06 +0000 |
Changes since v1:
* Wrap commit log at 70 chars.
Commit 4a946268 changed the default value of the structure
(PCIHostDeviceAddress) underlying the host property in vfio-pci to be ~0 in all
fields. Since this structure has excess bits for representing a standard BDF
(FFFF:FF:FF.F) this triggers an assert check designed to catch such invalid
BDFs in the get function of the property. This makes any code that attempts to
use get on the property fatal if the host device isn't specified using the now
optional host property.
To see the bug assign a vfio-pci device using the sysfsdev property instead of
the host property so that host gets the default "not present," value. Attempts
to display the property then crash the working emulation.
qemu-system-x86_64 -device
vfio-pci,id=gfxfn0,sysfsdev='/sys/bus/pci/devices/0000:01:00.0' -monitor stdio
QEMU 2.7.50 monitor - type 'help' for more information
(qemu) info qtree
bus: main-system-bus
....Omitted for brevity...
bus: pci.0
type PCI
dev: vfio-pci, id "gfxfn0"
qemu-system-x86_64: /home/xochip/source/qemu.git/hw/core/qdev-properties.c:717:
get_pci_host_devaddr: Assertion `rc == sizeof(buffer) - 1' failed.
The bug is minor because the structure involved is presumably insufficient and
redundant given the introduction of the new sysfsdev property. Since I'm new to
the code, I resisted the urge to make a mess by cleaning it up and attach a
totally minimal fix in the hope it makes the problem clearer and easier to
ignore. Happy to redo or leave it to somebody else as required.
Regards,
Dan.
Daniel Oram (1):
Fix assert in PCI address property when used by vfio-pci
hw/core/qdev-properties.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
--
2.10.2
- [Qemu-devel] [PATCH v2 0/1] vfio-pci: fix assert fail in host property if unused,
Daniel Oram <=