Let's add our virtio-mem-ccw proxy device and wire it up. We should
be supporting everything (e.g., device unplug, "dynamic-memslots") that
we already support for the virtio-pci variant.
With a Linux guest that supports virtio-mem (and has automatic memory
onlining properly configured) the following example will work:
1. Start a VM with 4G initial memory and a virtio-mem device with a maximum
capacity of 16GB:
qemu/build/qemu-system-s390x \
--enable-kvm \
-m 4G,maxmem=20G \
-nographic \
-smp 8 \
-hda Fedora-Server-KVM-40-1.14.s390x.qcow2 \
-chardev socket,id=monitor,path=/var/tmp/monitor,server,nowait \
-mon chardev=monitor,mode=readline \
-object memory-backend-ram,id=mem0,size=16G,reserve=off \
-device virtio-mem-ccw,id=vmem0,memdev=mem0,dynamic-memslots=on
2. Query the current size of virtio-mem device:
(qemu) info memory-devices
Memory device [virtio-mem]: "vmem0"
memaddr: 0x100000000
node: 0
requested-size: 0
size: 0
max-size: 17179869184
block-size: 1048576
memdev: /objects/mem0
3. Request to grow it to 8GB (hotplug 8GB):
(qemu) qom-set vmem0 requested-size 8G
(qemu) info memory-devices
Memory device [virtio-mem]: "vmem0"
memaddr: 0x100000000
node: 0
requested-size: 8589934592
size: 8589934592
max-size: 17179869184
block-size: 1048576
memdev: /objects/mem0
4. Request to grow to 16GB (hotplug another 8GB):
(qemu) qom-set vmem0 requested-size 16G
(qemu) info memory-devices
Memory device [virtio-mem]: "vmem0"
memaddr: 0x100000000
node: 0
requested-size: 17179869184
size: 17179869184
max-size: 17179869184
block-size: 1048576
memdev: /objects/mem0
5. Try to hotunplug all memory again, shrinking to 0GB:
(qemu) qom-set vmem0 requested-size 0G
(qemu) info memory-devices
Memory device [virtio-mem]: "vmem0"
memaddr: 0x100000000
node: 0
requested-size: 0
size: 0
max-size: 17179869184
block-size: 1048576
memdev: /objects/mem0
6. If it worked, unplug the device
(qemu) device_del vmem0
(qemu) info memory-devices
(qemu) object_del mem0
7. Hotplug a new device with a smaller capacity and directly size it to 1GB
(qemu) object_add memory-backend-ram,id=mem0,size=8G,reserve=off
(qemu) device_add virtio-mem-ccw,id=vmem0,memdev=mem0,\
dynamic-memslots=on,requested-size=1G
(qemu) info memory-devices
Memory device [virtio-mem]: "vmem0"
memaddr: 0x100000000
node: 0
requested-size: 1073741824
size: 1073741824
max-size: 8589934592
block-size: 1048576
memdev: /objects/mem0
Trying to use a virtio-mem device backed by hugetlb into a !hugetlb VM
correctly results in the error:
... Memory device uses a bigger page size than initial memory
Note that the virtio-mem driver in Linux will supports 1 MiB (pageblock)
granularity.
Message-ID: <20241219144115.2820241-15-david@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Commit e779e5c05a ("hw/pci-bridge: Add a Kconfig switch for the
normal PCI bridge") added a config switch for the pci-bridge, so
that the device is not included in the s390x target anymore (since
the pci-bridge is not really useful on s390x).
However, it seems like libvirt is still adding pci-bridge devices
automatically to the guests' XML definitions (when adding a PCI
device to a non-zero PCI bus), so these guests are now broken due
to the missing pci-bridge in the QEMU binary.
To avoid disruption of the users, let's re-enable the pci-bridge
device on s390x for the time being.
Message-ID: <20241024130405.62134-1-thuth@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Some targets use "default y" for boards to filter out those that require
TCG. For consistency we are switching all other targets to do the same.
Continue with s390.
No changes to generated config-devices.mak file.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If QEMU is built with --without-default-devices, the s390-flic-kvm
device is missing and QEMU aborts when started with the KVM accelerator.
Make sure it's available by selecting S390_FLIC_KVM in Kconfig.
Consequently, this also fixes an abort in tests/qtest/migration-test.
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Message-Id: <20230711151440.716822-1-clg@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
It is useful to extend the number of available PCIe devices to KVM guests
for passthrough scenarios and also to expose these models to a different
(big endian) architecture. Introduce a new config PCIE_DEVICES to select
models, Intel Ethernet adapters and one USB controller. These devices all
support MSI-X which is a requirement on s390x as legacy INTx are not
supported.
Cc: Matthew Rosato <mjrosato@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Huth <thuth@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Message-ID: <20230712080146.839113-1-clg@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Not all interrupt controllers have a working implementation of
message-signalled interrupts; in some cases, the guest may expect
MSI to work but it won't due to the buggy or lacking emulation.
In QEMU this is represented by the "msi_nonbroken" variable. This
patch adds a new configuration symbol enabled whenever the binary
contains an interrupt controller that will set "msi_nonbroken". We
can then use it to remove devices that cannot be possibly added
to the machine, because they require MSI.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Instead of hard-coding all config switches in the config file
default-configs/s390x-softmmu.mak, let's use the new Kconfig files
to express the necessary dependencies: The S390_CCW_VIRTIO config switch
for the "s390-ccw-virtio" machine now selects all non-optional devices.
And since we already have the VIRTIO_PCI and VIRTIO_MMIO config switches
for the other two virtio transports, this patch also introduces a new
config switch VIRTIO_CCW for the third, s390x-specific virtio transport,
so that all three virtio transports are now handled in the same way.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The Kconfig files were generated mostly with this script:
for i in `grep -ho CONFIG_[A-Z0-9_]* default-configs/* | sort -u`; do
set fnord `git grep -lw $i -- 'hw/*/Makefile.objs' `
shift
if test $# = 1; then
cat >> $(dirname $1)/Kconfig << EOF
config ${i#CONFIG_}
bool
EOF
git add $(dirname $1)/Kconfig
else
echo $i $*
fi
done
sed -i '$d' hw/*/Kconfig
for i in hw/*; do
if test -d $i && ! test -f $i/Kconfig; then
touch $i/Kconfig
git add $i/Kconfig
fi
done
Whenever a symbol is referenced from multiple subdirectories, the
script prints the list of directories that reference the symbol.
These symbols have to be added manually to the Kconfig files.
Kconfig.host and hw/Kconfig were created manually.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20190123065618.3520-27-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
