public inbox for pve-devel@lists.proxmox.com
 help / color / mirror / Atom feed
From: Fiona Ebner <f.ebner@proxmox.com>
To: pve-devel@lists.proxmox.com
Subject: [PATCH-SERIES qemu-server 0/4] cpu config: warn that OVMF might limit phys-bits to 40 without pdpe1gb CPU flag
Date: Mon, 23 Mar 2026 14:27:20 +0100	[thread overview]
Message-ID: <20260323132857.125747-1-f.ebner@proxmox.com> (raw)

OVMF limits phys-bits to 40 if no 1 GiB pages are available. When
built in debug mode, OVMF logs a debug message about this. But
otherwise, there is no user-visible log of this happening.

In practice, VMs with a lot of memory or VMs with GPU passthrough with
a lot of vRAM might not boot when the pdpe1gb CPU flag is not present.
In particular, this is the case for the built-in x86-64-vX models that
are based on the qemu64 model as well as the backend default kvm64.

It can't be expected that Proxmox VE users check the EDK II source
code to figure this out, so log a warning. The warning is limited to
CPU models based on the qemu64 and kvm64 models, since checking for
other models would require the CPU model expansion which is currently
not cheap to get. This should cover most problematic scenarios.

qemu-server:

Fiona Ebner (4):
  cpu config: split resolve_cpu_flags() function
  move get_host_phys_address_bits() to helpers module
  cpu config: get cpu options: avoid shadowing $conf variable
  cpu config: warn that OVMF might limit phys-bits to 40 without pdpe1gb
    CPU flag

 src/PVE/QemuServer/CPUConfig.pm      | 43 ++++++++++++++++++++++++----
 src/PVE/QemuServer/Helpers.pm        | 18 ++++++++++++
 src/PVE/QemuServer/Memory.pm         | 23 ++-------------
 src/test/run_config2command_tests.pl | 11 +++++--
 4 files changed, 67 insertions(+), 28 deletions(-)


Summary over all repositories:
  4 files changed, 67 insertions(+), 28 deletions(-)

-- 
Generated by git-murpp 0.5.0




             reply	other threads:[~2026-03-23 13:29 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-23 13:27 Fiona Ebner [this message]
2026-03-23 13:27 ` [PATCH qemu-server 1/4] cpu config: split resolve_cpu_flags() function Fiona Ebner
2026-03-23 13:27 ` [PATCH qemu-server 2/4] move get_host_phys_address_bits() to helpers module Fiona Ebner
2026-03-23 13:27 ` [PATCH qemu-server 3/4] cpu config: get cpu options: avoid shadowing $conf variable Fiona Ebner
2026-03-23 13:27 ` [PATCH qemu-server 4/4] cpu config: warn that OVMF might limit phys-bits to 40 without pdpe1gb CPU flag Fiona Ebner

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=20260323132857.125747-1-f.ebner@proxmox.com \
    --to=f.ebner@proxmox.com \
    --cc=pve-devel@lists.proxmox.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
Service provided by Proxmox Server Solutions GmbH | Privacy | Legal