In various place we don't correctly check if the device supports MSI or
MSI-X. This can cause devices to be advertised with MSI support, even
if they only support MSI-X (like virtio-pci-* devices for example):
ethernet@0 {
ibm,req#msi = <0x1>; <--- wrong!
.
ibm,loc-code = "qemu_virtio-net-pci:0000:00:00.0";
.
ibm,req#msi-x = <0x3>;
};
Worse, this can also cause the "ibm,change-msi" RTAS call to corrupt the
PCI status and cause migration to fail:
qemu-system-ppc64: get_pci_config_device: Bad config data: i=0x6
read: 0 device: 10 cmask: 10 wmask: 0 w1cmask:0
^^
PCI_STATUS_CAP_LIST bit which is assumed to be constant
This patch changes spapr_populate_pci_child_dt() to properly check for
MSI support using msi_present(): this ensures that PCIDevice::msi_cap
was set by msi_init() and that msi_nr_vectors_allocated() will look at
the right place in the config space.
Checking PCIDevice::msix_entries_nr is enough for MSI-X but let's add
a call to msix_present() there as well for consistency.
It also changes rtas_ibm_change_msi() to select the appropriate MSI
type in Function 1 instead of always selecting plain MSI. This new
behaviour is compliant with LoPAPR 1.1, as described in "Table 71.
ibm,change-msi Argument Call Buffer":
Function 1: If Number Outputs is equal to 3, request to set to a new
number of MSIs (including set to 0).
If the “ibm,change-msix-capable” property exists and Number
Outputs is equal to 4, request is to set to a new number of
MSI or MSI-X (platform choice) interrupts (including set to
0).
Since MSI is the the platform default (LoPAPR 6.2.3 MSI Option), let's
check for MSI support first.
And finally, it checks the input parameters are valid, as described in
LoPAPR 1.1 "R1–7.3.10.5.1–3":
For the MSI option: The platform must return a Status of -3 (Parameter
error) from ibm,change-msi, with no change in interrupt assignments if
the PCI configuration address does not support MSI and Function 3 was
requested (that is, the “ibm,req#msi” property must exist for the PCI
configuration address in order to use Function 3), or does not support
MSI-X and Function 4 is requested (that is, the “ibm,req#msi-x” property
must exist for the PCI configuration address in order to use Function 4),
or if neither MSIs nor MSI-Xs are supported and Function 1 is requested.
This ensures that the ret_intr_type variable contains a valid MSI type
for this device, and that spapr_msi_setmsg() won't corrupt the PCI status.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
QEMU README
===========
QEMU is a generic and open source machine & userspace emulator and
virtualizer.
QEMU is capable of emulating a complete machine in software without any
need for hardware virtualization support. By using dynamic translation,
it achieves very good performance. QEMU can also integrate with the Xen
and KVM hypervisors to provide emulated hardware while allowing the
hypervisor to manage the CPU. With hypervisor support, QEMU can achieve
near native performance for CPUs. When QEMU emulates CPUs directly it is
capable of running operating systems made for one machine (e.g. an ARMv7
board) on a different machine (e.g. an x86_64 PC board).
QEMU is also capable of providing userspace API virtualization for Linux
and BSD kernel interfaces. This allows binaries compiled against one
architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a
different architecture ABI (e.g. the Linux x86_64 ABI). This does not
involve any hardware emulation, simply CPU and syscall emulation.
QEMU aims to fit into a variety of use cases. It can be invoked directly
by users wishing to have full control over its behaviour and settings.
It also aims to facilitate integration into higher level management
layers, by providing a stable command line interface and monitor API.
It is commonly invoked indirectly via the libvirt library when using
open source applications such as oVirt, OpenStack and virt-manager.
QEMU as a whole is released under the GNU General Public License,
version 2. For full licensing details, consult the LICENSE file.
Building
========
QEMU is multi-platform software intended to be buildable on all modern
Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety
of other UNIX targets. The simple steps to build QEMU are:
mkdir build
cd build
../configure
make
Additional information can also be found online via the QEMU website:
https://qemu.org/Hosts/Linux
https://qemu.org/Hosts/Mac
https://qemu.org/Hosts/W32
Submitting patches
==================
The QEMU source code is maintained under the GIT version control system.
git clone git://git.qemu.org/qemu.git
When submitting patches, the preferred approach is to use 'git
format-patch' and/or 'git send-email' to format & send the mail to the
qemu-devel@nongnu.org mailing list. All patches submitted must contain
a 'Signed-off-by' line from the author. Patches should follow the
guidelines set out in the HACKING and CODING_STYLE files.
Additional information on submitting patches can be found online via
the QEMU website
https://qemu.org/Contribute/SubmitAPatch
https://qemu.org/Contribute/TrivialPatches
Bug reporting
=============
The QEMU project uses Launchpad as its primary upstream bug tracker. Bugs
found when running code built from QEMU git or upstream released sources
should be reported via:
https://bugs.launchpad.net/qemu/
If using QEMU via an operating system vendor pre-built binary package, it
is preferable to report bugs to the vendor's own bug tracker first. If
the bug is also known to affect latest upstream code, it can also be
reported via launchpad.
For additional information on bug reporting consult:
https://qemu.org/Contribute/ReportABug
Contact
=======
The QEMU community can be contacted in a number of ways, with the two
main methods being email and IRC
- qemu-devel@nongnu.org
https://lists.nongnu.org/mailman/listinfo/qemu-devel
- #qemu on irc.oftc.net
Information on additional methods of contacting the community can be
found online via the QEMU website:
https://qemu.org/Contribute/StartHere
-- End
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