On 26.05.20 15:28, Vivek Goyal wrote: > On Mon, May 25, 2020 at 10:45:11AM +0200, David Hildenbrand wrote: >> E.g., with "pc-q35-4.2", trying to coldplug a virtio-pmem-pci devices >> results in >> "virtio-pmem-pci not supported on this bus" >> >> Reasons is, that the bus does not support hotplug and, therefore, does >> not have a hotplug handler. Let's allow coldplugging virtio-pmem devices >> on such buses. The hotplug order is only relevant for virtio-pmem-pci >> when the guest is already alive and the device is visible before >> memory_device_plug() wired up the memory device bits. >> >> Hotplug attempts will still fail with: >> "Error: Bus 'pcie.0' does not support hotplugging" >> >> Hotunplug attempts will still fail with: >> "Error: Bus 'pcie.0' does not support hotplugging" >> >> Reported-by: Vivek Goyal <vgo...@redhat.com> >> Cc: Pankaj Gupta <pankaj.gupta.li...@gmail.com> >> Cc: Igor Mammedov <imamm...@redhat.com> >> Cc: Paolo Bonzini <pbonz...@redhat.com> >> Cc: Richard Henderson <r...@twiddle.net> >> Cc: Eduardo Habkost <ehabk...@redhat.com> >> Cc: "Michael S. Tsirkin" <m...@redhat.com> >> Cc: Marcel Apfelbaum <marcel.apfelb...@gmail.com> >> Signed-off-by: David Hildenbrand <da...@redhat.com> >> --- >> hw/i386/pc.c | 18 ++++++++++-------- >> 1 file changed, 10 insertions(+), 8 deletions(-) > > Thanks for the patch David. I still seem to face a different error though. > > 2020-05-26T13:26:05.720617Z qemu-system-x86_64: -device > virtio-pmem-pci,memdev=pmem1,id=nv1: memory devices (e.g. for memory hotplug) > are not enabled, please specify the maxmem option > > Following is my domain xml file. > > Vivek
Hi Vivek, you have to declare the maxMemory option. Memory devices like virtio-pmem-pci reside in RAM like a pc-dimm or a nvdimm. If your virtio-pmem device will be 4GB, you have to add that to maxMemory. <memory unit='GiB'>64</memory> <maxMemory unit='GiB'>68</maxMemory> <currentMemory unit='GiB'>64</currentMemory> (you might have to add "slots='0'" or "slots='1'" to maxMemory to make libvirt happy) @Pankaj, do we have a virtio-pmem doc somewhere describing how to set it up? -- Thanks, David / dhildenb
