title: comand "lspci" does not show the the IVSHMEM device
body: <p>I met a problem when I tried to use IVSHMEM.
  Below is the configuration from my side:</p>
  <ol>
  <li>vm xml configuration for IVSHMEM device:</li>
  </ol>
  <pre><code>&lt;shmem name='ivshmem'&gt;
      &lt;model type='ivshmem-plain'/&gt;
      &lt;size unit='M'&gt;2&lt;/size&gt;
      &lt;address type='pci' domain='0x0000' bus='0x00' slot='0x10' function='0x0'/&gt;
  &lt;/shmem&gt;
  </code></pre>
  <ol start="2">
  <li><p>after the booting up and I found the qemu commandline ideedly have the device option:</p>
  <p>ps aux | grep ivshmem</p>
  </li>
  </ol>
  <blockquote>
  <p>/usr/bin/qemu-system-x86_64
  .......(ignore other options)
  -object memory-backend-file,id=shmmem-shmem0,mem-path=/dev/shm/hostmem,size=4194304,share=yes -device ivshmem-plain,id=shmem0,memdev=shmmem-shmem0,bus=pcie.0,addr=0x10</p>
  </blockquote>
  <ol start="3">
  <li><p>lspci command  not shown the device.</p>
  </li>
  <li><p>lshw command indeedly show the device:</p>
  </li>
  </ol>
  <pre><code>*-memory UNCLAIMED
               description: RAM memory
               product: Inter-VM shared memory
               vendor: Red Hat, Inc.
               physical id: 10
               bus info: pci@0000:00:10.0
               version: 01
               width: 64 bits
               clock: 33MHz (30.3ns)
               configuration: latency=0
               resources: memory:fcc1c000-fcc1c0ff memory:fdc00000-fdffffff
  </code></pre>
  <p>My host os and gust vm os is ubuntu 20.04 and version is:</p>
  <pre><code>uname -a
  </code></pre>
  <p>5.8.0-43-generic #49~20.04.1-Ubuntu SMP Fri Feb 5 09:57:56 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux</p>
  <p>Anything input on this one?</p>