From: Eugenio Perez Martin <eperezma@redhat.com>
To: Sahil <icegambit91@gmail.com>
Cc: qemu-level <qemu-devel@nongnu.org>,
Stefano Garzarella <sgarzare@redhat.com>
Subject: Re: Intention to work on GSoC project
Date: Mon, 15 Apr 2024 10:57:36 +0200 [thread overview]
Message-ID: <CAJaqyWcxK6i6iYiktPhq59gg0G8YzkD0X+Ji0XbOVgK0E1Hdwg@mail.gmail.com> (raw)
In-Reply-To: <2192541.Mh6RI2rZIc@valdaarhun>
On Sun, Apr 14, 2024 at 8:52 PM Sahil <icegambit91@gmail.com> wrote:
>
> Hi,
>
> On Friday, April 5, 2024 12:36:02 AM IST Sahil wrote:
> > [...]
> > I'll set up this environment as well.
>
> I would like to post an update here. I spent the last week
> trying to set up the environment as described in the blog [1].
> I initially tried to get the L1 VM running on my host machine
> (Arch Linux). However, I was unable to use virt-sysprep or
> virt-cutomize to install packages in the qcow2 image. It wasn't
> able to resolve the hosts while downloading the packages.
>
> According to the logs, /etc/resolv.conf was a dangling symlink.
> I tried to use "virt-rescue" to configure DNS resolution. I tried
> following these sections [2], [3] in the Arch wiki but that didn't
> work either. I tried using qemu-nbd as well following this section
> [4] to access the image. While I managed gain access to the
> image, I wasn't able to install packages after performing a
> chroot.
>
> One workaround was to set this environment up in a VM. I
> decided to set up the environment with a Fedora image in
> virtualbox acting as L0. I have managed to set up an L1 VM
> in this environment and I can load it using qemu-kvm.
>
I'm not clear if the complaint of the dangling pointer comes from the
host or from the guest env, but I think it is ok to continue if you've
been able to build the env.
> I have one question though. One of the options (use case 1 in [1])
> given to the "qemu-kvm" command is:
> > -device virtio-net-pci,netdev=vhost-vdpa0,bus=pcie.0,addr=0x7\
> > ,disable-modern=off,page-per-vq=on
>
> This gives an error:
> > Bus "pcie.0" not found
>
> Does pcie refer to PCI Express? Changing this to pci.0 works.
Yes, you don't need to mess with pcie stuff so this solution is
totally valid. I think we need to change that part in the tutorial.
> I read through the "device buses" section in QEMU's user
> documentation [5], but I have still not understood this.
>
> "ls /sys/bus/pci/devices/* | grep vdpa" does not give any results.
> Replacing pci with pci_express doesn't give any results either. How
> does one know which pci bus the vdpa device is connected to?
> I have gone through the "vDPA bus drivers" section of the "vDPA
> kernel framework" article [6] but I haven't managed to find an
> answer yet. Am I missing something here?
>
You cannot see the vDPA device from the guest. From the guest POV is a
regular virtio over PCI bus.
From the host, vdpa_sim is not a PCI device either, so you cannot see
under /sys/bus. Do you have a vdpa* entry under
/sys/bus/vdpa/devices/?
> There's one more thing. In "use case 1" of "Running traffic with
> vhost_vdpa in Guest" [1], running "modprobe pktgen" in the L1 VM
> gives an error:
> > module pktgen couldn't be found in /lib/modules/6.5.6-300.fc39.x86_64.
>
> The kernel version is 6.5.6-300.fc39.x86_64. I haven't tried building
> pktgen manually in L1. I'll try that and will check if vdpa_sim works
> as expected after that.
>
Did you install kernel-modules-internal?
Thanks!
> [1] https://www.redhat.com/en/blog/hands-vdpa-what-do-you-do-when-you-aint-got-hardware-part-1
> [2] https://wiki.archlinux.org/title/QEMU#User-mode_networking
> [3] https://wiki.archlinux.org/title/Systemd-networkd#Required_services_and_setup
> [4] https://wiki.archlinux.org/title/QEMU#Mounting_a_partition_from_a_qcow2_image
> [5] https://qemu-project.gitlab.io/qemu/system/device-emulation.html
> [6] https://www.redhat.com/en/blog/vdpa-kernel-framework-part-1-vdpa-bus-abstracting-hardware
>
> Thanks,
> Sahil
>
>
next prev parent reply other threads:[~2024-04-15 8:59 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-25 21:38 Intention to work on GSoC project Sahil
2024-02-29 8:32 ` Stefano Garzarella
2024-02-29 19:02 ` Sahil
2024-03-01 7:40 ` Eugenio Perez Martin
2024-03-01 18:29 ` Sahil
2024-03-14 15:09 ` Eugenio Perez Martin
2024-03-15 7:14 ` Sahil
2024-03-15 11:27 ` Eugenio Perez Martin
2024-03-16 20:26 ` Sahil
2024-03-18 19:47 ` Sahil
2024-03-20 16:29 ` Eugenio Perez Martin
2024-03-25 13:20 ` Sahil
2024-04-01 18:23 ` daleyoung4242
2024-04-02 4:58 ` Sahil
2024-04-02 11:38 ` Eugenio Perez Martin
2024-04-03 14:36 ` Sahil
2024-04-03 18:37 ` Eugenio Perez Martin
2024-04-04 19:06 ` Sahil
2024-04-14 18:52 ` Sahil
2024-04-15 8:57 ` Eugenio Perez Martin [this message]
2024-04-15 19:42 ` Sahil
2024-04-16 8:41 ` Eugenio Perez Martin
2024-04-17 4:23 ` Sahil
2024-05-06 19:00 ` Sahil
2024-05-07 7:14 ` Eugenio Perez Martin
2024-05-08 3:23 ` Sahil
2024-05-13 13:49 ` Sahil
2024-05-13 14:23 ` Eugenio Perez Martin
2024-05-13 18:04 ` Sahil
2024-03-20 15:57 ` Eugenio Perez Martin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAJaqyWcxK6i6iYiktPhq59gg0G8YzkD0X+Ji0XbOVgK0E1Hdwg@mail.gmail.com \
--to=eperezma@redhat.com \
--cc=icegambit91@gmail.com \
--cc=qemu-devel@nongnu.org \
--cc=sgarzare@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).