XCP-ng
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups
    • Register
    • Login

    Could not change "-machine" by 'xe vm-param-set'

    Scheduled Pinned Locked Moved Compute
    6 Posts 3 Posters 1.3k Views 3 Watching
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • L Offline
      lyan
      last edited by

      With default xcp-ng 8.2, I saw the hvm is created with "qemu-dm-3 -machine pc-0.10,accel=xen,"

      I checked xe vm-param-setthat there is no such option change "-machine", I tried "other-config" got no such key error.

      I am new to xcp-ng, wondering if there is a way to change the machine model for qemu, such as "pc-i440fx-42".

      Thanks.

      1 Reply Last reply Reply Quote 0
      • olivierlambertO Offline
        olivierlambert Vates πŸͺ Co-Founder CEO
        last edited by

        Hi,

        You can't change that in XCP-ng. Can you tell us what do you want to achieve?

        L 1 Reply Last reply Reply Quote 0
        • L Offline
          lyan @olivierlambert
          last edited by

          Thanks for the reply, @olivierlambert. I recently hit a bug that Xen could not create msi interrupt for HVM, I noticed that we qemu-dm is using pc-0.1 as the machine model by default, as the starter, I kind of want to change it to i440fx-4.2 which is aligned to the qemu version. I can not change it from the cmd line atm, maybe it is hard-wired in the code?

          T 1 Reply Last reply Reply Quote 0
          • olivierlambertO olivierlambert moved this topic from Xen Orchestra on
          • olivierlambertO Offline
            olivierlambert Vates πŸͺ Co-Founder CEO
            last edited by

            I think it's slightly more complicated than that. Adding @ThierryEscande in the loop

            1 Reply Last reply Reply Quote 0
            • T Offline
              ThierryEscande Vates πŸͺ XCP-ng Team @lyan
              last edited by

              Hi @lyan,

              This might be related to a known issue about PCI passthrough with nvme devices: the kernel tries to allocate more MSI-X vectors than the guest can handle. You can try to increase the number of guest IRQs with the Xen boot parameter extra_guest_irqs. The default is 64 and you can increase it to 128 with:

              /opt/xensource/libexec/xen-cmdline --set-xen "extra_guest_irqs=128"

              A reboot of the host is needed.

              L 1 Reply Last reply Reply Quote 1
              • L Offline
                lyan @ThierryEscande
                last edited by

                Hi, @ThierryEscande, thanks for the input here。

                It is pretty interesting that I kind also located the same place by following the interrupter path.
                https://github.com/liayan/xen-xcp-ng/blob/main/xen/common/domain.c#L250

                It quite fits our case atm that issues happened after hitting the limit of 64. Unfortunately, I can not test it yet because our host is stuck in a weird POST status. Will update here later.

                1 Reply Last reply Reply Quote 1

                Hello! It looks like you're interested in this conversation, but you don't have an account yet.

                Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.

                With your input, this post could be even better πŸ’—

                Register Login
                • First post
                  Last post