Commit 60032dc6 authored by Rocky Automation's avatar Rocky Automation 📺
Browse files

import libguestfs-1.46.1-4.el9_0

parent 05466244
From 06cf41cdddfde07871a7f7033ba8c5ccc184a1fb Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Thu, 12 May 2022 08:36:37 +0100
Subject: [PATCH] lib: Disable 5-level page tables when using -cpu max
In https://bugzilla.redhat.com/show_bug.cgi?id=2082806 we've been
tracking an insidious qemu bug which intermittently prevents the
libguestfs appliance from starting. The symptoms are that SeaBIOS
starts and displays its messages, but the kernel isn't reached. We
found that the kernel does in fact start, but when it tries to set up
page tables and jump to protected mode it gets a triple fault which
causes the emulated CPU in qemu to reset (qemu exits).
This seems to only affect TCG (not KVM).
Yesterday I found that this is caused by using -cpu max which enables
the "la57" feature (5-level page tables[0]), and that we can make the
problem go away using -cpu max,la57=off. Note that I still don't
fully understand the qemu bug, so this is only a workaround.
I chose to disable 5-level page tables for both TCG and KVM, partly to
make the patch simpler, and partly because I guess it's not a feature
(ie. 57 bit linear addresses) that is useful for the libguestfs
appliance case, where we have limited physical memory and no need to
run any programs with huge address spaces.
I tested this by running both the direct & libvirt paths overnight. I
expect that this patch will fail with old qemu/libvirt which doesn't
understand the "la57" feature, but this is only intended as a
temporary workaround.
[0] Article about 5-level page tables as background:
https://lwn.net/Articles/717293/
Thanks: Laszlo Ersek
Fixes: https://answers.launchpad.net/ubuntu/+source/libguestfs/+question/701625
Acked-by: Laszlo Ersek <lersek@redhat.com>
(cherry picked from commit 59d7e6e017b7de79bcb60e1180e15303f1e7dae8)
---
lib/launch-direct.c | 15 +++++++++++++--
lib/launch-libvirt.c | 7 +++++++
2 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/lib/launch-direct.c b/lib/launch-direct.c
index 4f038f4f0..e7c22fbef 100644
--- a/lib/launch-direct.c
+++ b/lib/launch-direct.c
@@ -554,8 +554,19 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
} end_list ();
cpu_model = guestfs_int_get_cpu_model (has_kvm && !force_tcg);
- if (cpu_model)
- arg ("-cpu", cpu_model);
+ if (cpu_model) {
+#if defined(__x86_64__)
+ /* Temporary workaround for RHBZ#2082806 */
+ if (STREQ (cpu_model, "max")) {
+ start_list ("-cpu") {
+ append_list (cpu_model);
+ append_list ("la57=off");
+ } end_list ();
+ }
+ else
+#endif
+ arg ("-cpu", cpu_model);
+ }
if (g->smp > 1)
arg_format ("-smp", "%d", g->smp);
diff --git a/lib/launch-libvirt.c b/lib/launch-libvirt.c
index cc714c02e..9e32c94cf 100644
--- a/lib/launch-libvirt.c
+++ b/lib/launch-libvirt.c
@@ -1185,6 +1185,13 @@ construct_libvirt_xml_cpu (guestfs_h *g,
else if (STREQ (cpu_model, "max")) {
/* https://bugzilla.redhat.com/show_bug.cgi?id=1935572#c11 */
attribute ("mode", "maximum");
+#if defined(__x86_64__)
+ /* Temporary workaround for RHBZ#2082806 */
+ start_element ("feature") {
+ attribute ("policy", "disable");
+ attribute ("name", "la57");
+ } end_element ();
+#endif
}
else
single_element ("model", cpu_model);
--
2.31.1
......@@ -57,7 +57,7 @@ Summary: Access and modify virtual machine disk images
Name: libguestfs
Epoch: 1
Version: 1.46.1
Release: 3%{?dist}.rocky
Release: 4%{?dist}.rocky
License: LGPLv2+
# Build only for architectures that have a kernel
......@@ -108,7 +108,8 @@ Patch0010: 0010-RHEL-Remove-User-Mode-Linux-RHBZ-1144197.patch
Patch0011: 0011-RHEL-Reject-use-of-libguestfs-winsupport-features-ex.patch
Patch0012: 0012-RHEL-Create-etc-crypto-policies-back-ends-opensslcnf.patch
Patch0013: 0013-daemon-rpm-c.c-Disable-signature-checking-in-librpm.patch
Patch14: 0001-Add-ROCKY-to-list-of-REDHAT-distros.patch
Patch0014: 0014-lib-Disable-5-level-page-tables-when-using-cpu-max.patch
Patch15: 0001-Add-ROCKY-to-list-of-REDHAT-distros.patch
%if 0%{patches_touch_autotools}
BuildRequires: autoconf, automake, libtool, gettext-devel
......@@ -1148,9 +1149,13 @@ rm ocaml/html/.gitignore
%changelog
* Fri May 20 2022 Release Engineering <releng@rockylinux.org> - 1.46.1-3.rocky
* Tue Aug 09 2022 Release Engineering <releng@rockylinux.org> - 1.46.1-4.rocky
- Add ROCKY to list of REDHAT distros
* Sun May 15 2022 Richard W.M. Jones <rjones@redhat.com> - 1:1.46.1-4
- Disable 5-level page tables when using -cpu max
resolves: rhbz#2085527
* Thu Mar 17 2022 Richard W.M. Jones <rjones@redhat.com> - 1:1.46.1-3
- Disable signature checking in librpm
resolves: rhbz#2064182
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment