While installing the experemental kernel on a CentOS 7 PV the following happened. After a reboot of the PV the kernel looks to be installed but there is no option for booting it in grub.  I attempted to run yum reinstall kernel-4.9.75-204.el7.centos.x86_64 and it installed fine but still no entry in grub. No initramfs existed and I found kernel-modules did not install properly so I then ran yum reinstall kernel-modules and received a ton of errors that looked like the following..

depmod: ERROR: failed to load symbols from /lib/modules/4.9.75-204.el7.centos.x86_64/kernel/drivers/misc/sgi-xp/xpc.ko.xz: Exec format error

after which a initramfs does exist however on reboot still no option for the new kernel.


[root@CC0A2543 ~]# [  587.145018] ------------[ cut here ]------------
[  587.145018] kernel BUG at arch/x86/kernel/paravirt.c:244!
[  587.145018] invalid opcode: 0000 [#1] SMP
[  587.145018] Modules linked in: xen_netfront coretemp pcspkr ip_tables ext4 mbcache jbd2 xen_blkfront
[  587.145018] CPU: 0 PID: 2126 Comm: dracut Not tainted 3.10.0-123.4.4.el7.x86_64 #1
[  587.145018] task: ffff880002da5b00 ti: ffff8800f6088000 task.ti: ffff8800f6088000
[  587.145018] RIP: e030:[<ffffffff815da23b>]  [<ffffffff815da23b>] enter_lazy.part.0+0x4/0x6
[  587.145018] RSP: e02b:ffff8800ff403ab0  EFLAGS: 00010002
[  587.145018] RAX: 0000000000000001 RBX: ffff8800f8ad4040 RCX: 00003ffffffff000
[  587.145018] RDX: ffff880000000040 RSI: ffff880000000000 RDI: 00000005a52cc067
[  587.145018] RBP: ffff8800ff403ab0 R08: ffff8800ff403b78 R09: ffffffff81362409
[  587.145018] R10: ffff8800fa001e00 R11: ffff880000000000 R12: ffffc90000609000
[  587.145018] R13: ffffc90000608000 R14: 0000000000000000 R15: ffffffff8100a6b0
[  587.145018] FS:  00007f14b0680740(0000) GS:ffff8800ff400000(0000) knlGS:0000000000000000
[  587.145018] CS:  e033 DS: 0000 ES: 0000 CR0: 000000008005003b
[  587.145018] CR2: 00007f14b0473000 CR3: 00000000f6099000 CR4: 0000000000002660
[  587.145018] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  587.145018] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  587.145018] Stack:
[  587.145018]  ffff8800ff403ac0 ffffffff81046bc7 ffff8800ff403b60 ffffffff8116d8d6
[  587.145018]  ffffc90000608fff ffffc90000609000 ffffffff818cec90 ffffc90000608fff
[  587.145018]  ffffc90000609000 ffff8800fa04d000 0000000000000004 ffffc90000608fff
[  587.145018] Call Trace:
[  587.145018]  <IRQ>
[  587.145018]  [<ffffffff81046bc7>] paravirt_enter_lazy_mmu+0x27/0x30
[  587.145018]  [<ffffffff8116d8d6>] apply_to_page_range+0x266/0x440
[  587.145018]  [<ffffffff8100a7fb>] arch_gnttab_map_status+0x3b/0x70
[  587.145018]  [<ffffffff81362486>] gnttab_map_frames_v2+0xd6/0x150
[  587.145018]  [<ffffffff813625a1>] gnttab_map+0xa1/0x140
[  587.145018]  [<ffffffff81362740>] get_free_entries+0x100/0x2e0
[  587.145018]  [<ffffffff813629e5>] gnttab_alloc_grant_references+0x15/0x30
[  587.145018]  [<ffffffffa0000cc3>] do_blkif_request+0x683/0x850 [xen_blkfront]
[  587.145018]  [<ffffffff812906c3>] __blk_run_queue+0x33/0x40
[  587.145018]  [<ffffffff812906f9>] blk_start_queue+0x29/0x40
[  587.145018]  [<ffffffffa0000eb1>] kick_pending_request_queues+0x21/0x30 [xen_blkfront]
[  587.145018]  [<ffffffffa0001487>] blkif_interrupt+0x5c7/0x670 [xen_blkfront]
[  587.145018]  [<ffffffff810f735e>] handle_irq_event_percpu+0x3e/0x1e0
[  587.145018]  [<ffffffff810f753d>] handle_irq_event+0x3d/0x60
[  587.145018]  [<ffffffff810fa1c7>] handle_edge_irq+0x77/0x130
[  587.145018]  [<ffffffff81363527>] __xen_evtchn_do_upcall+0x227/0x350
[  587.145018]  [<ffffffff813656db>] xen_evtchn_do_upcall+0x2b/0x50
[  587.145018]  [<ffffffff815f3f7e>] xen_do_hypervisor_callback+0x1e/0x30
[  587.145018]  <EOI>
[  587.145018]  [<ffffffff812b8419>] ? free_cpumask_var+0x9/0x10
[  587.145018]  [<ffffffff81169618>] ? unmap_page_range+0x5f8/0x860
[  587.145018]  [<ffffffff81169901>] ? unmap_single_vma+0x81/0xf0
[  587.145018]  [<ffffffff8116a9c9>] ? unmap_vmas+0x49/0x90
[  587.145018]  [<ffffffff8117367c>] ? exit_mmap+0xac/0x1a0
[  587.145018]  [<ffffffff8105b187>] ? mmput+0x67/0xf0
[  587.145018]  [<ffffffff811b6c32>] ? flush_old_exec+0x422/0x880
[  587.145018]  [<ffffffff812069cc>] ? load_elf_binary+0x33c/0xde0
[  587.145018]  [<ffffffff81272b13>] ? ima_get_action+0x23/0x30
[  587.145018]  [<ffffffff8127217e>] ? process_measurement+0x8e/0x250
[  587.145018]  [<ffffffff81272639>] ? ima_bprm_check+0x49/0x50
[  587.145018]  [<ffffffff81206690>] ? load_elf_library+0x230/0x230
[  587.145018]  [<ffffffff811b6355>] ? search_binary_handler+0xf5/0x310
[  587.145018]  [<ffffffff811b78e9>] ? do_execve_common.isra.22+0x559/0x650
[  587.145018]  [<ffffffff811b7c76>] ? SyS_execve+0x36/0x50
[  587.145018]  [<ffffffff815f2b89>] ? stub_execve+0x69/0xa0
[  587.145018] Code: 8d 55 f0 48 8d 4d f4 e8 b4 8e a2 ff 66 90 48 8b 55 f8 65 48 33 14 25 28 00 00 00 8b 45 e8 74 05 e8 ab 3a a8 ff c9 c3 55 48 89 e5 <0f> 0b 66 66 66 66 90 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 66 66
[  587.145018] RIP  [<ffffffff815da23b>] enter_lazy.part.0+0x4/0x6
[  587.145018]  RSP <ffff8800ff403ab0>
[  587.145018] ---[ end trace 8566ed161f106c20 ]---
[  587.145018] Kernel panic - not syncing: Fatal exception in interrupt




--
Shaun Reitan
NDCHost.com

------ Original Message ------
From: "Johnny Hughes" <johnny@centos.org>
To: centos-virt@centos.org
Sent: 2018-01-06 05:34:22 AM
Subject: Re: [CentOS-virt] Centos 7 Kernel 3.10.0-693.11.6.el7.x86_64 does not boot PV

On 01/06/2018 03:16 AM, Dmitry Melekhov wrote:
The same problem with latest centos 6 kernel,i.e. with meltdown fix.
 
I can't see console output, because I have it on "cloud" provider
hosting :-)
 
 
 
06.01.2018 05:13, Shaun Reitan пишет:
Broken!
 
 
 
 
For those of you looking for a PV enabled client Kernel for CentOS Linux
7 DomU VMs, you can use our Experimental kernel from here:
 
http://mirror.centos.org/altarch/7/experimental/x86_64/
 
There is a repo file at the BOTTOM of this wiki page that you can use to
enable the experimental repo:
 
https://wiki.centos.org/SpecialInterestGroup/AltArch/i386
 
That experimental repo file will work for x86_64 or i386 installs and
the latest released kernel (kernel-4.9.75-204.el7.centos). This kernel
has the CONFIG_PAGE_TABLE_ISOLATION=y security fixes (used to be
CONFIG_KAISER .. and still is in the Red Hat released kernels).
 
You could also use the Dom0 kernels from the Xen repo as DomU kernels
for your PV VMs if you want. Currently the 4.9.75 Xen kernels are in
the testing repo and waiting for tests to release.
 
Thanks,
Johnny Hughes