* domU crash when resuming from suspend - Xen 4.22
@ 2026-06-19 11:24 Marek Marczykowski-Górecki
2026-07-14 17:12 ` Marek Marczykowski-Górecki
0 siblings, 1 reply; 10+ messages in thread
From: Marek Marczykowski-Górecki @ 2026-06-19 11:24 UTC (permalink / raw)
To: xen-devel
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Hi,
I'm continuing testing 4.22 and found this:
When a domU is suspended (even without host suspend) it crashes on
resume with:
[ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020
[ 24.374647] #PF: supervisor read access in kernel mode
[ 24.374657] #PF: error_code(0x0000) - not-present page
[ 24.374668] PGD 0 P4D 0
[ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI
[ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full)
[ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0
[ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140
[ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd
[ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046
[ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404
[ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0
[ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c
[ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0
[ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000
[ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0
[ 24.374873] PKRU: 00000000
[ 24.374877] Call Trace:
[ 24.374884] <TASK>
[ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10
[ 24.374900] cpu_stopper_thread+0xa3/0x170
[ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10
[ 24.374917] smpboot_thread_fn+0xf3/0x220
[ 24.374925] kthread+0xfc/0x240
[ 24.374933] ? __pfx_kthread+0x10/0x10
[ 24.374940] ? __pfx_kthread+0x10/0x10
[ 24.374949] ret_from_fork+0x158/0x170
[ 24.374957] ? __pfx_kthread+0x10/0x10
[ 24.374965] ret_from_fork_asm+0x1a/0x30
[ 24.374973] </TASK>
[ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront
[ 24.375064] CR2: 0000000000000020
[ 24.375071] ---[ end trace 0000000000000000 ]---
[ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140
[ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd
[ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046
[ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404
[ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0
[ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c
[ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0
[ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000
[ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0
[ 24.375241] PKRU: 00000000
[ 24.375247] Kernel panic - not syncing: Fatal exception
[ 25.417403] Shutting down cpus with NMI
[ 25.417447] Kernel Offset: disabled
There is no change on the Linux kernel side (neither dom0 nor domU), the
only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already
broken on -rc1 too). This happens for both HVM and PVH domains. Haven't
tried PV domU (but dom0 survives host suspend).
--
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
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^ permalink raw reply [flat|nested] 10+ messages in thread* Re: domU crash when resuming from suspend - Xen 4.22 2026-06-19 11:24 domU crash when resuming from suspend - Xen 4.22 Marek Marczykowski-Górecki @ 2026-07-14 17:12 ` Marek Marczykowski-Górecki 2026-07-15 6:16 ` Jan Beulich 2026-07-17 20:22 ` Frediano Ziglio 0 siblings, 2 replies; 10+ messages in thread From: Marek Marczykowski-Górecki @ 2026-07-14 17:12 UTC (permalink / raw) To: xen-devel [-- Attachment #1: Type: text/plain, Size: 4681 bytes --] On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: > Hi, > > I'm continuing testing 4.22 and found this: > > When a domU is suspended (even without host suspend) it crashes on > resume with: > > [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 > [ 24.374647] #PF: supervisor read access in kernel mode > [ 24.374657] #PF: error_code(0x0000) - not-present page > [ 24.374668] PGD 0 P4D 0 > [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI > [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) > [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 > [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 > [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > [ 24.374873] PKRU: 00000000 > [ 24.374877] Call Trace: > [ 24.374884] <TASK> > [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 > [ 24.374900] cpu_stopper_thread+0xa3/0x170 > [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 > [ 24.374917] smpboot_thread_fn+0xf3/0x220 > [ 24.374925] kthread+0xfc/0x240 > [ 24.374933] ? __pfx_kthread+0x10/0x10 > [ 24.374940] ? __pfx_kthread+0x10/0x10 > [ 24.374949] ret_from_fork+0x158/0x170 > [ 24.374957] ? __pfx_kthread+0x10/0x10 > [ 24.374965] ret_from_fork_asm+0x1a/0x30 > [ 24.374973] </TASK> > [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront > [ 24.375064] CR2: 0000000000000020 > [ 24.375071] ---[ end trace 0000000000000000 ]--- > [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 > [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > [ 24.375241] PKRU: 00000000 > [ 24.375247] Kernel panic - not syncing: Fatal exception > [ 25.417403] Shutting down cpus with NMI > [ 25.417447] Kernel Offset: disabled > > There is no change on the Linux kernel side (neither dom0 nor domU), the > only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already > broken on -rc1 too). This happens for both HVM and PVH domains. Haven't > tried PV domU (but dom0 survives host suspend). Any ideas? -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: domU crash when resuming from suspend - Xen 4.22 2026-07-14 17:12 ` Marek Marczykowski-Górecki @ 2026-07-15 6:16 ` Jan Beulich 2026-07-17 20:22 ` Frediano Ziglio 1 sibling, 0 replies; 10+ messages in thread From: Jan Beulich @ 2026-07-15 6:16 UTC (permalink / raw) To: Marek Marczykowski-Górecki; +Cc: xen-devel On 14.07.2026 19:12, Marek Marczykowski-Górecki wrote: > On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: >> Hi, >> >> I'm continuing testing 4.22 and found this: >> >> When a domU is suspended (even without host suspend) it crashes on >> resume with: >> >> [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 >> [ 24.374647] #PF: supervisor read access in kernel mode >> [ 24.374657] #PF: error_code(0x0000) - not-present page >> [ 24.374668] PGD 0 P4D 0 >> [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI >> [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) >> [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 >> [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 >> [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd >> [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 >> [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 >> [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 >> [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c >> [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 >> [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 >> [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 >> [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 >> [ 24.374873] PKRU: 00000000 >> [ 24.374877] Call Trace: >> [ 24.374884] <TASK> >> [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 >> [ 24.374900] cpu_stopper_thread+0xa3/0x170 >> [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 >> [ 24.374917] smpboot_thread_fn+0xf3/0x220 >> [ 24.374925] kthread+0xfc/0x240 >> [ 24.374933] ? __pfx_kthread+0x10/0x10 >> [ 24.374940] ? __pfx_kthread+0x10/0x10 >> [ 24.374949] ret_from_fork+0x158/0x170 >> [ 24.374957] ? __pfx_kthread+0x10/0x10 >> [ 24.374965] ret_from_fork_asm+0x1a/0x30 >> [ 24.374973] </TASK> >> [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront >> [ 24.375064] CR2: 0000000000000020 >> [ 24.375071] ---[ end trace 0000000000000000 ]--- >> [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 >> [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd >> [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 >> [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 >> [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 >> [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c >> [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 >> [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 >> [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 >> [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 >> [ 24.375241] PKRU: 00000000 >> [ 24.375247] Kernel panic - not syncing: Fatal exception >> [ 25.417403] Shutting down cpus with NMI >> [ 25.417447] Kernel Offset: disabled >> >> There is no change on the Linux kernel side (neither dom0 nor domU), the >> only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already >> broken on -rc1 too). This happens for both HVM and PVH domains. Haven't >> tried PV domU (but dom0 survives host suspend). > > Any ideas? Didn't you indicate on Matrix that there's also a kernel version dependency? Iirc 6.12 doesn't exhibit the issue. Short of anyone having a good idea from just the data available, perhaps the next step would be to further limit version ranges on both sides? Jan ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: domU crash when resuming from suspend - Xen 4.22 2026-07-14 17:12 ` Marek Marczykowski-Górecki 2026-07-15 6:16 ` Jan Beulich @ 2026-07-17 20:22 ` Frediano Ziglio 2026-07-18 14:03 ` Marek Marczykowski-Górecki 1 sibling, 1 reply; 10+ messages in thread From: Frediano Ziglio @ 2026-07-17 20:22 UTC (permalink / raw) To: Marek Marczykowski-Górecki; +Cc: xen-devel On Tue, 14 Jul 2026 at 18:12, Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> wrote: > > On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: > > Hi, > > > > I'm continuing testing 4.22 and found this: > > > > When a domU is suspended (even without host suspend) it crashes on > > resume with: > > > > [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 > > [ 24.374647] #PF: supervisor read access in kernel mode > > [ 24.374657] #PF: error_code(0x0000) - not-present page > > [ 24.374668] PGD 0 P4D 0 > > [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI > > [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) > > [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 > > [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 > > [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > [ 24.374873] PKRU: 00000000 > > [ 24.374877] Call Trace: > > [ 24.374884] <TASK> > > [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 > > [ 24.374900] cpu_stopper_thread+0xa3/0x170 > > [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 > > [ 24.374917] smpboot_thread_fn+0xf3/0x220 > > [ 24.374925] kthread+0xfc/0x240 > > [ 24.374933] ? __pfx_kthread+0x10/0x10 > > [ 24.374940] ? __pfx_kthread+0x10/0x10 > > [ 24.374949] ret_from_fork+0x158/0x170 > > [ 24.374957] ? __pfx_kthread+0x10/0x10 > > [ 24.374965] ret_from_fork_asm+0x1a/0x30 > > [ 24.374973] </TASK> > > [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront > > [ 24.375064] CR2: 0000000000000020 > > [ 24.375071] ---[ end trace 0000000000000000 ]--- > > [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 > > [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > [ 24.375241] PKRU: 00000000 > > [ 24.375247] Kernel panic - not syncing: Fatal exception > > [ 25.417403] Shutting down cpus with NMI > > [ 25.417447] Kernel Offset: disabled > > > > There is no change on the Linux kernel side (neither dom0 nor domU), the > > only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already > > broken on -rc1 too). This happens for both HVM and PVH domains. Haven't > > tried PV domU (but dom0 survives host suspend). > > Any ideas? > Hi, not many ideas but while testing my libxenguest changes I found similar failures using xl create/save/restore. But I was testing more PV guests. Does 4.21 work ? Frediano ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: domU crash when resuming from suspend - Xen 4.22 2026-07-17 20:22 ` Frediano Ziglio @ 2026-07-18 14:03 ` Marek Marczykowski-Górecki 2026-07-19 1:59 ` Marek Marczykowski-Górecki 0 siblings, 1 reply; 10+ messages in thread From: Marek Marczykowski-Górecki @ 2026-07-18 14:03 UTC (permalink / raw) To: Frediano Ziglio; +Cc: xen-devel [-- Attachment #1: Type: text/plain, Size: 5538 bytes --] On Fri, Jul 17, 2026 at 09:22:47PM +0100, Frediano Ziglio wrote: > On Tue, 14 Jul 2026 at 18:12, Marek Marczykowski-Górecki > <marmarek@invisiblethingslab.com> wrote: > > > > On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: > > > Hi, > > > > > > I'm continuing testing 4.22 and found this: > > > > > > When a domU is suspended (even without host suspend) it crashes on > > > resume with: > > > > > > [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 > > > [ 24.374647] #PF: supervisor read access in kernel mode > > > [ 24.374657] #PF: error_code(0x0000) - not-present page > > > [ 24.374668] PGD 0 P4D 0 > > > [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI > > > [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) > > > [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 > > > [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > [ 24.374873] PKRU: 00000000 > > > [ 24.374877] Call Trace: > > > [ 24.374884] <TASK> > > > [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 > > > [ 24.374900] cpu_stopper_thread+0xa3/0x170 > > > [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 > > > [ 24.374917] smpboot_thread_fn+0xf3/0x220 > > > [ 24.374925] kthread+0xfc/0x240 > > > [ 24.374933] ? __pfx_kthread+0x10/0x10 > > > [ 24.374940] ? __pfx_kthread+0x10/0x10 > > > [ 24.374949] ret_from_fork+0x158/0x170 > > > [ 24.374957] ? __pfx_kthread+0x10/0x10 > > > [ 24.374965] ret_from_fork_asm+0x1a/0x30 > > > [ 24.374973] </TASK> > > > [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront > > > [ 24.375064] CR2: 0000000000000020 > > > [ 24.375071] ---[ end trace 0000000000000000 ]--- > > > [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > [ 24.375241] PKRU: 00000000 > > > [ 24.375247] Kernel panic - not syncing: Fatal exception > > > [ 25.417403] Shutting down cpus with NMI > > > [ 25.417447] Kernel Offset: disabled > > > > > > There is no change on the Linux kernel side (neither dom0 nor domU), the > > > only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already > > > broken on -rc1 too). This happens for both HVM and PVH domains. Haven't > > > tried PV domU (but dom0 survives host suspend). > > > > Any ideas? > > > > Hi, > not many ideas but while testing my libxenguest changes I found > similar failures using xl create/save/restore. But I was testing more > PV guests. > Does 4.21 work ? It seems 4.21 also has this issue: https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414211523 But 4.20 is okay: https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414227095 I guess I can bisect it further. -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: domU crash when resuming from suspend - Xen 4.22 2026-07-18 14:03 ` Marek Marczykowski-Górecki @ 2026-07-19 1:59 ` Marek Marczykowski-Górecki 2026-07-19 7:31 ` Frediano Ziglio 0 siblings, 1 reply; 10+ messages in thread From: Marek Marczykowski-Górecki @ 2026-07-19 1:59 UTC (permalink / raw) To: Frediano Ziglio; +Cc: xen-devel, Andrew Cooper [-- Attachment #1: Type: text/plain, Size: 6304 bytes --] On Sat, Jul 18, 2026 at 04:03:29PM +0200, Marek Marczykowski-Górecki wrote: > On Fri, Jul 17, 2026 at 09:22:47PM +0100, Frediano Ziglio wrote: > > On Tue, 14 Jul 2026 at 18:12, Marek Marczykowski-Górecki > > <marmarek@invisiblethingslab.com> wrote: > > > > > > On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: > > > > Hi, > > > > > > > > I'm continuing testing 4.22 and found this: > > > > > > > > When a domU is suspended (even without host suspend) it crashes on > > > > resume with: > > > > > > > > [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 > > > > [ 24.374647] #PF: supervisor read access in kernel mode > > > > [ 24.374657] #PF: error_code(0x0000) - not-present page > > > > [ 24.374668] PGD 0 P4D 0 > > > > [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI > > > > [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) > > > > [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 > > > > [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > [ 24.374873] PKRU: 00000000 > > > > [ 24.374877] Call Trace: > > > > [ 24.374884] <TASK> > > > > [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 > > > > [ 24.374900] cpu_stopper_thread+0xa3/0x170 > > > > [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 > > > > [ 24.374917] smpboot_thread_fn+0xf3/0x220 > > > > [ 24.374925] kthread+0xfc/0x240 > > > > [ 24.374933] ? __pfx_kthread+0x10/0x10 > > > > [ 24.374940] ? __pfx_kthread+0x10/0x10 > > > > [ 24.374949] ret_from_fork+0x158/0x170 > > > > [ 24.374957] ? __pfx_kthread+0x10/0x10 > > > > [ 24.374965] ret_from_fork_asm+0x1a/0x30 > > > > [ 24.374973] </TASK> > > > > [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront > > > > [ 24.375064] CR2: 0000000000000020 > > > > [ 24.375071] ---[ end trace 0000000000000000 ]--- > > > > [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > [ 24.375241] PKRU: 00000000 > > > > [ 24.375247] Kernel panic - not syncing: Fatal exception > > > > [ 25.417403] Shutting down cpus with NMI > > > > [ 25.417447] Kernel Offset: disabled > > > > > > > > There is no change on the Linux kernel side (neither dom0 nor domU), the > > > > only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already > > > > broken on -rc1 too). This happens for both HVM and PVH domains. Haven't > > > > tried PV domU (but dom0 survives host suspend). > > > > > > Any ideas? > > > > > > > Hi, > > not many ideas but while testing my libxenguest changes I found > > similar failures using xl create/save/restore. But I was testing more > > PV guests. > > Does 4.21 work ? > > It seems 4.21 also has this issue: > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414211523 > But 4.20 is okay: > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414227095 > > I guess I can bisect it further. So, bisect says the first bad commit is: commit 9f892f84c27970840d255aef7e2851b762967de7 Author: Andrew Cooper <andrew.cooper3@citrix.com> Date: Mon Dec 30 11:49:14 2024 +0000 x86/domctl: Stop using XLAT_cpu_user_regs() My test isn't 100% reliable, but I retested parent of this commit a couple of times and it was good every time. I wanted to test reverting it on top of 4.21, but there is a lot of FRED-related work on top that makes such revert quite hard, to say the least... -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: domU crash when resuming from suspend - Xen 4.22 2026-07-19 1:59 ` Marek Marczykowski-Górecki @ 2026-07-19 7:31 ` Frediano Ziglio 2026-07-19 19:40 ` Marek Marczykowski-Górecki 0 siblings, 1 reply; 10+ messages in thread From: Frediano Ziglio @ 2026-07-19 7:31 UTC (permalink / raw) To: Marek Marczykowski-Górecki; +Cc: xen-devel, Andrew Cooper On Sun, 19 Jul 2026 at 03:00, Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> wrote: > > On Sat, Jul 18, 2026 at 04:03:29PM +0200, Marek Marczykowski-Górecki wrote: > > On Fri, Jul 17, 2026 at 09:22:47PM +0100, Frediano Ziglio wrote: > > > On Tue, 14 Jul 2026 at 18:12, Marek Marczykowski-Górecki > > > <marmarek@invisiblethingslab.com> wrote: > > > > > > > > On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: > > > > > Hi, > > > > > > > > > > I'm continuing testing 4.22 and found this: > > > > > > > > > > When a domU is suspended (even without host suspend) it crashes on > > > > > resume with: > > > > > > > > > > [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 > > > > > [ 24.374647] #PF: supervisor read access in kernel mode > > > > > [ 24.374657] #PF: error_code(0x0000) - not-present page > > > > > [ 24.374668] PGD 0 P4D 0 > > > > > [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI > > > > > [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) > > > > > [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 > > > > > [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > > [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > > [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > > [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > > [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > > [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > > [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > > [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > > [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > > [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > > [ 24.374873] PKRU: 00000000 > > > > > [ 24.374877] Call Trace: > > > > > [ 24.374884] <TASK> > > > > > [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 > > > > > [ 24.374900] cpu_stopper_thread+0xa3/0x170 > > > > > [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 > > > > > [ 24.374917] smpboot_thread_fn+0xf3/0x220 > > > > > [ 24.374925] kthread+0xfc/0x240 > > > > > [ 24.374933] ? __pfx_kthread+0x10/0x10 > > > > > [ 24.374940] ? __pfx_kthread+0x10/0x10 > > > > > [ 24.374949] ret_from_fork+0x158/0x170 > > > > > [ 24.374957] ? __pfx_kthread+0x10/0x10 > > > > > [ 24.374965] ret_from_fork_asm+0x1a/0x30 > > > > > [ 24.374973] </TASK> > > > > > [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront > > > > > [ 24.375064] CR2: 0000000000000020 > > > > > [ 24.375071] ---[ end trace 0000000000000000 ]--- > > > > > [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > > [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > > [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > > [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > > [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > > [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > > [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > > [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > > [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > > [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > > [ 24.375241] PKRU: 00000000 > > > > > [ 24.375247] Kernel panic - not syncing: Fatal exception > > > > > [ 25.417403] Shutting down cpus with NMI > > > > > [ 25.417447] Kernel Offset: disabled > > > > > > > > > > There is no change on the Linux kernel side (neither dom0 nor domU), the > > > > > only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already > > > > > broken on -rc1 too). This happens for both HVM and PVH domains. Haven't > > > > > tried PV domU (but dom0 survives host suspend). > > > > > > > > Any ideas? > > > > > > > > > > Hi, > > > not many ideas but while testing my libxenguest changes I found > > > similar failures using xl create/save/restore. But I was testing more > > > PV guests. > > > Does 4.21 work ? > > > > It seems 4.21 also has this issue: > > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414211523 > > But 4.20 is okay: > > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414227095 > > > > I guess I can bisect it further. > > So, bisect says the first bad commit is: > > commit 9f892f84c27970840d255aef7e2851b762967de7 > Author: Andrew Cooper <andrew.cooper3@citrix.com> > Date: Mon Dec 30 11:49:14 2024 +0000 > > x86/domctl: Stop using XLAT_cpu_user_regs() > > My test isn't 100% reliable, but I retested parent of this commit a > couple of times and it was good every time. > > I wanted to test reverting it on top of 4.21, but there is a lot of > FRED-related work on top that makes such revert quite hard, to say the > least... > The generated XLAT_cpu_user_regs was #define XLAT_cpu_user_regs(_d_, _s_) do { \ (_d_)->__DECL_REG_LO8(b) = (_s_)->__DECL_REG_LO8(b); \ (_d_)->__DECL_REG_LO8(c) = (_s_)->__DECL_REG_LO8(c); \ (_d_)->__DECL_REG_LO8(d) = (_s_)->__DECL_REG_LO8(d); \ (_d_)->__DECL_REG_LO16(si) = (_s_)->__DECL_REG_LO16(si); \ (_d_)->__DECL_REG_LO16(di) = (_s_)->__DECL_REG_LO16(di); \ (_d_)->__DECL_REG_LO16(bp) = (_s_)->__DECL_REG_LO16(bp); \ (_d_)->__DECL_REG_LO8(a) = (_s_)->__DECL_REG_LO8(a); \ (_d_)->error_code = (_s_)->error_code; \ (_d_)->entry_vector = (_s_)->entry_vector; \ (_d_)->__DECL_REG_LO16(ip) = (_s_)->__DECL_REG_LO16(ip); \ (_d_)->cs = (_s_)->cs; \ (_d_)->saved_upcall_mask = (_s_)->saved_upcall_mask; \ (_d_)->__DECL_REG_LO16(flags) = (_s_)->__DECL_REG_LO16(flags); \ (_d_)->__DECL_REG_LO16(sp) = (_s_)->__DECL_REG_LO16(sp); \ (_d_)->ss = (_s_)->ss; \ (_d_)->es = (_s_)->es; \ (_d_)->ds = (_s_)->ds; \ (_d_)->fs = (_s_)->fs; \ (_d_)->gs = (_s_)->gs; \ } while (0) registers are copied, but additional fields (error_code, entry_vector, saved_upcall_mask). Maybe you could try to copy them again. Also, just to be on the safe side, you could memset the structure where "Backing memory is pre-zeroed" comments are. Frediano ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: domU crash when resuming from suspend - Xen 4.22 2026-07-19 7:31 ` Frediano Ziglio @ 2026-07-19 19:40 ` Marek Marczykowski-Górecki 2026-07-19 21:04 ` Frediano Ziglio 0 siblings, 1 reply; 10+ messages in thread From: Marek Marczykowski-Górecki @ 2026-07-19 19:40 UTC (permalink / raw) To: Frediano Ziglio; +Cc: xen-devel, Andrew Cooper [-- Attachment #1: Type: text/plain, Size: 9461 bytes --] On Sun, Jul 19, 2026 at 08:31:28AM +0100, Frediano Ziglio wrote: > On Sun, 19 Jul 2026 at 03:00, Marek Marczykowski-Górecki > <marmarek@invisiblethingslab.com> wrote: > > > > On Sat, Jul 18, 2026 at 04:03:29PM +0200, Marek Marczykowski-Górecki wrote: > > > On Fri, Jul 17, 2026 at 09:22:47PM +0100, Frediano Ziglio wrote: > > > > On Tue, 14 Jul 2026 at 18:12, Marek Marczykowski-Górecki > > > > <marmarek@invisiblethingslab.com> wrote: > > > > > > > > > > On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: > > > > > > Hi, > > > > > > > > > > > > I'm continuing testing 4.22 and found this: > > > > > > > > > > > > When a domU is suspended (even without host suspend) it crashes on > > > > > > resume with: > > > > > > > > > > > > [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 > > > > > > [ 24.374647] #PF: supervisor read access in kernel mode > > > > > > [ 24.374657] #PF: error_code(0x0000) - not-present page > > > > > > [ 24.374668] PGD 0 P4D 0 > > > > > > [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI > > > > > > [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) > > > > > > [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 > > > > > > [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > > > [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > > > [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > > > [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > > > [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > > > [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > > > [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > > > [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > > > [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > > > [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > > [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > > > [ 24.374873] PKRU: 00000000 > > > > > > [ 24.374877] Call Trace: > > > > > > [ 24.374884] <TASK> > > > > > > [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 > > > > > > [ 24.374900] cpu_stopper_thread+0xa3/0x170 > > > > > > [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 > > > > > > [ 24.374917] smpboot_thread_fn+0xf3/0x220 > > > > > > [ 24.374925] kthread+0xfc/0x240 > > > > > > [ 24.374933] ? __pfx_kthread+0x10/0x10 > > > > > > [ 24.374940] ? __pfx_kthread+0x10/0x10 > > > > > > [ 24.374949] ret_from_fork+0x158/0x170 > > > > > > [ 24.374957] ? __pfx_kthread+0x10/0x10 > > > > > > [ 24.374965] ret_from_fork_asm+0x1a/0x30 > > > > > > [ 24.374973] </TASK> > > > > > > [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront > > > > > > [ 24.375064] CR2: 0000000000000020 > > > > > > [ 24.375071] ---[ end trace 0000000000000000 ]--- > > > > > > [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > > > [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > > > [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > > > [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > > > [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > > > [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > > > [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > > > [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > > > [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > > > [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > > [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > > > [ 24.375241] PKRU: 00000000 > > > > > > [ 24.375247] Kernel panic - not syncing: Fatal exception > > > > > > [ 25.417403] Shutting down cpus with NMI > > > > > > [ 25.417447] Kernel Offset: disabled > > > > > > > > > > > > There is no change on the Linux kernel side (neither dom0 nor domU), the > > > > > > only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already > > > > > > broken on -rc1 too). This happens for both HVM and PVH domains. Haven't > > > > > > tried PV domU (but dom0 survives host suspend). > > > > > > > > > > Any ideas? > > > > > > > > > > > > > Hi, > > > > not many ideas but while testing my libxenguest changes I found > > > > similar failures using xl create/save/restore. But I was testing more > > > > PV guests. > > > > Does 4.21 work ? > > > > > > It seems 4.21 also has this issue: > > > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414211523 > > > But 4.20 is okay: > > > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414227095 > > > > > > I guess I can bisect it further. > > > > So, bisect says the first bad commit is: > > > > commit 9f892f84c27970840d255aef7e2851b762967de7 > > Author: Andrew Cooper <andrew.cooper3@citrix.com> > > Date: Mon Dec 30 11:49:14 2024 +0000 > > > > x86/domctl: Stop using XLAT_cpu_user_regs() > > > > My test isn't 100% reliable, but I retested parent of this commit a > > couple of times and it was good every time. > > > > I wanted to test reverting it on top of 4.21, but there is a lot of > > FRED-related work on top that makes such revert quite hard, to say the > > least... > > > > The generated XLAT_cpu_user_regs was > > #define XLAT_cpu_user_regs(_d_, _s_) do { \ > (_d_)->__DECL_REG_LO8(b) = (_s_)->__DECL_REG_LO8(b); \ > (_d_)->__DECL_REG_LO8(c) = (_s_)->__DECL_REG_LO8(c); \ > (_d_)->__DECL_REG_LO8(d) = (_s_)->__DECL_REG_LO8(d); \ > (_d_)->__DECL_REG_LO16(si) = (_s_)->__DECL_REG_LO16(si); \ > (_d_)->__DECL_REG_LO16(di) = (_s_)->__DECL_REG_LO16(di); \ > (_d_)->__DECL_REG_LO16(bp) = (_s_)->__DECL_REG_LO16(bp); \ > (_d_)->__DECL_REG_LO8(a) = (_s_)->__DECL_REG_LO8(a); \ > (_d_)->error_code = (_s_)->error_code; \ > (_d_)->entry_vector = (_s_)->entry_vector; \ > (_d_)->__DECL_REG_LO16(ip) = (_s_)->__DECL_REG_LO16(ip); \ > (_d_)->cs = (_s_)->cs; \ > (_d_)->saved_upcall_mask = (_s_)->saved_upcall_mask; \ > (_d_)->__DECL_REG_LO16(flags) = (_s_)->__DECL_REG_LO16(flags); \ > (_d_)->__DECL_REG_LO16(sp) = (_s_)->__DECL_REG_LO16(sp); \ > (_d_)->ss = (_s_)->ss; \ > (_d_)->es = (_s_)->es; \ > (_d_)->ds = (_s_)->ds; \ > (_d_)->fs = (_s_)->fs; \ > (_d_)->gs = (_s_)->gs; \ > } while (0) > > registers are copied, but additional fields (error_code, entry_vector, > saved_upcall_mask). > Maybe you could try to copy them again. > Also, just to be on the safe side, you could memset the structure > where "Backing memory is pre-zeroed" comments are. This does not help :( Specifically: 1. Applied on top of staging-4.21: - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/188ca612c51a57ef54b917c833eaeb59666994c9 - test (fails): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688813821 2. Applied directly on top of 9f892f84c27970840d255aef7e2851b762967de7: - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/dd3dee35fc4fcd6ba284f3f5fa78b333c472888e - test (fails): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688832398 Yet, parent of 9f892f84c27970840d255aef7e2851b762967de7 still passes: - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/dbcbbed4e9dc25faa211d359c2f04a9c70f087c9 - test (pass): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688835512 Hint about reading the above: I use two branches, one for building (branch "test") and one for running the test (branch "automation-uki-grub-only"), which takes build artifacts from the build branch. I do that to not rebase test scripts. It's a bit opaque, but the console log of the test contains "Latest ChangeSet" fields telling what actually was tested. -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: domU crash when resuming from suspend - Xen 4.22 2026-07-19 19:40 ` Marek Marczykowski-Górecki @ 2026-07-19 21:04 ` Frediano Ziglio 2026-07-19 22:50 ` Marek Marczykowski-Górecki 0 siblings, 1 reply; 10+ messages in thread From: Frediano Ziglio @ 2026-07-19 21:04 UTC (permalink / raw) To: Marek Marczykowski-Górecki; +Cc: xen-devel, Andrew Cooper On Sun, 19 Jul 2026 at 20:40, Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> wrote: > > On Sun, Jul 19, 2026 at 08:31:28AM +0100, Frediano Ziglio wrote: > > On Sun, 19 Jul 2026 at 03:00, Marek Marczykowski-Górecki > > <marmarek@invisiblethingslab.com> wrote: > > > > > > On Sat, Jul 18, 2026 at 04:03:29PM +0200, Marek Marczykowski-Górecki wrote: > > > > On Fri, Jul 17, 2026 at 09:22:47PM +0100, Frediano Ziglio wrote: > > > > > On Tue, 14 Jul 2026 at 18:12, Marek Marczykowski-Górecki > > > > > <marmarek@invisiblethingslab.com> wrote: > > > > > > > > > > > > On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: > > > > > > > Hi, > > > > > > > > > > > > > > I'm continuing testing 4.22 and found this: > > > > > > > > > > > > > > When a domU is suspended (even without host suspend) it crashes on > > > > > > > resume with: > > > > > > > > > > > > > > [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 > > > > > > > [ 24.374647] #PF: supervisor read access in kernel mode > > > > > > > [ 24.374657] #PF: error_code(0x0000) - not-present page > > > > > > > [ 24.374668] PGD 0 P4D 0 > > > > > > > [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI > > > > > > > [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) > > > > > > > [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 > > > > > > > [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > > > > [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > > > > [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > > > > [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > > > > [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > > > > [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > > > > [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > > > > [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > > > > [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > > > > [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > > > [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > > > > [ 24.374873] PKRU: 00000000 > > > > > > > [ 24.374877] Call Trace: > > > > > > > [ 24.374884] <TASK> > > > > > > > [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 > > > > > > > [ 24.374900] cpu_stopper_thread+0xa3/0x170 > > > > > > > [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 > > > > > > > [ 24.374917] smpboot_thread_fn+0xf3/0x220 > > > > > > > [ 24.374925] kthread+0xfc/0x240 > > > > > > > [ 24.374933] ? __pfx_kthread+0x10/0x10 > > > > > > > [ 24.374940] ? __pfx_kthread+0x10/0x10 > > > > > > > [ 24.374949] ret_from_fork+0x158/0x170 > > > > > > > [ 24.374957] ? __pfx_kthread+0x10/0x10 > > > > > > > [ 24.374965] ret_from_fork_asm+0x1a/0x30 > > > > > > > [ 24.374973] </TASK> > > > > > > > [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront > > > > > > > [ 24.375064] CR2: 0000000000000020 > > > > > > > [ 24.375071] ---[ end trace 0000000000000000 ]--- > > > > > > > [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > > > > [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > > > > [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > > > > [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > > > > [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > > > > [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > > > > [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > > > > [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > > > > [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > > > > [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > > > [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > > > > [ 24.375241] PKRU: 00000000 > > > > > > > [ 24.375247] Kernel panic - not syncing: Fatal exception > > > > > > > [ 25.417403] Shutting down cpus with NMI > > > > > > > [ 25.417447] Kernel Offset: disabled > > > > > > > > > > > > > > There is no change on the Linux kernel side (neither dom0 nor domU), the > > > > > > > only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already > > > > > > > broken on -rc1 too). This happens for both HVM and PVH domains. Haven't > > > > > > > tried PV domU (but dom0 survives host suspend). > > > > > > > > > > > > Any ideas? > > > > > > > > > > > > > > > > Hi, > > > > > not many ideas but while testing my libxenguest changes I found > > > > > similar failures using xl create/save/restore. But I was testing more > > > > > PV guests. > > > > > Does 4.21 work ? > > > > > > > > It seems 4.21 also has this issue: > > > > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414211523 > > > > But 4.20 is okay: > > > > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414227095 > > > > > > > > I guess I can bisect it further. > > > > > > So, bisect says the first bad commit is: > > > > > > commit 9f892f84c27970840d255aef7e2851b762967de7 > > > Author: Andrew Cooper <andrew.cooper3@citrix.com> > > > Date: Mon Dec 30 11:49:14 2024 +0000 > > > > > > x86/domctl: Stop using XLAT_cpu_user_regs() > > > > > > My test isn't 100% reliable, but I retested parent of this commit a > > > couple of times and it was good every time. > > > > > > I wanted to test reverting it on top of 4.21, but there is a lot of > > > FRED-related work on top that makes such revert quite hard, to say the > > > least... > > > > > > > The generated XLAT_cpu_user_regs was > > > > #define XLAT_cpu_user_regs(_d_, _s_) do { \ > > (_d_)->__DECL_REG_LO8(b) = (_s_)->__DECL_REG_LO8(b); \ > > (_d_)->__DECL_REG_LO8(c) = (_s_)->__DECL_REG_LO8(c); \ > > (_d_)->__DECL_REG_LO8(d) = (_s_)->__DECL_REG_LO8(d); \ > > (_d_)->__DECL_REG_LO16(si) = (_s_)->__DECL_REG_LO16(si); \ > > (_d_)->__DECL_REG_LO16(di) = (_s_)->__DECL_REG_LO16(di); \ > > (_d_)->__DECL_REG_LO16(bp) = (_s_)->__DECL_REG_LO16(bp); \ > > (_d_)->__DECL_REG_LO8(a) = (_s_)->__DECL_REG_LO8(a); \ > > (_d_)->error_code = (_s_)->error_code; \ > > (_d_)->entry_vector = (_s_)->entry_vector; \ > > (_d_)->__DECL_REG_LO16(ip) = (_s_)->__DECL_REG_LO16(ip); \ > > (_d_)->cs = (_s_)->cs; \ > > (_d_)->saved_upcall_mask = (_s_)->saved_upcall_mask; \ > > (_d_)->__DECL_REG_LO16(flags) = (_s_)->__DECL_REG_LO16(flags); \ > > (_d_)->__DECL_REG_LO16(sp) = (_s_)->__DECL_REG_LO16(sp); \ > > (_d_)->ss = (_s_)->ss; \ > > (_d_)->es = (_s_)->es; \ > > (_d_)->ds = (_s_)->ds; \ > > (_d_)->fs = (_s_)->fs; \ > > (_d_)->gs = (_s_)->gs; \ > > } while (0) > > > > registers are copied, but additional fields (error_code, entry_vector, > > saved_upcall_mask). > > Maybe you could try to copy them again. > > Also, just to be on the safe side, you could memset the structure > > where "Backing memory is pre-zeroed" comments are. > > This does not help :( > > Specifically: > 1. Applied on top of staging-4.21: > - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/188ca612c51a57ef54b917c833eaeb59666994c9 > - test (fails): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688813821 > 2. Applied directly on top of 9f892f84c27970840d255aef7e2851b762967de7: > - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/dd3dee35fc4fcd6ba284f3f5fa78b333c472888e > - test (fails): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688832398 > > Yet, parent of 9f892f84c27970840d255aef7e2851b762967de7 still passes: > - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/dbcbbed4e9dc25faa211d359c2f04a9c70f087c9 > - test (pass): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688835512 > > Hint about reading the above: I use two branches, one for building > (branch "test") and one for running the test (branch "automation-uki-grub-only"), > which takes build artifacts from the build branch. I do that to not > rebase test scripts. It's a bit opaque, but the console log of the test > contains "Latest ChangeSet" fields telling what actually was tested. > If it does not take long to test you could revert hunk by hunk starting from xen/include/xlat.lst. Frediano ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: domU crash when resuming from suspend - Xen 4.22 2026-07-19 21:04 ` Frediano Ziglio @ 2026-07-19 22:50 ` Marek Marczykowski-Górecki 0 siblings, 0 replies; 10+ messages in thread From: Marek Marczykowski-Górecki @ 2026-07-19 22:50 UTC (permalink / raw) To: Frediano Ziglio; +Cc: xen-devel, Andrew Cooper [-- Attachment #1: Type: text/plain, Size: 12708 bytes --] On Sun, Jul 19, 2026 at 10:04:42PM +0100, Frediano Ziglio wrote: > On Sun, 19 Jul 2026 at 20:40, Marek Marczykowski-Górecki > <marmarek@invisiblethingslab.com> wrote: > > > > On Sun, Jul 19, 2026 at 08:31:28AM +0100, Frediano Ziglio wrote: > > > On Sun, 19 Jul 2026 at 03:00, Marek Marczykowski-Górecki > > > <marmarek@invisiblethingslab.com> wrote: > > > > > > > > On Sat, Jul 18, 2026 at 04:03:29PM +0200, Marek Marczykowski-Górecki wrote: > > > > > On Fri, Jul 17, 2026 at 09:22:47PM +0100, Frediano Ziglio wrote: > > > > > > On Tue, 14 Jul 2026 at 18:12, Marek Marczykowski-Górecki > > > > > > <marmarek@invisiblethingslab.com> wrote: > > > > > > > > > > > > > > On Fri, Jun 19, 2026 at 01:24:09PM +0200, Marek Marczykowski-Górecki wrote: > > > > > > > > Hi, > > > > > > > > > > > > > > > > I'm continuing testing 4.22 and found this: > > > > > > > > > > > > > > > > When a domU is suspended (even without host suspend) it crashes on > > > > > > > > resume with: > > > > > > > > > > > > > > > > [ 24.374629] BUG: kernel NULL pointer dereference, address: 0000000000000020 > > > > > > > > [ 24.374647] #PF: supervisor read access in kernel mode > > > > > > > > [ 24.374657] #PF: error_code(0x0000) - not-present page > > > > > > > > [ 24.374668] PGD 0 P4D 0 > > > > > > > > [ 24.374675] Oops: Oops: 0000 [#1] SMP NOPTI > > > > > > > > [ 24.374685] CPU: 0 UID: 0 PID: 19 Comm: migration/0 Not tainted 6.18.31-1.qubes.13.fc41.x86_64 #1 PREEMPT(full) > > > > > > > > [ 24.374705] Stopper: multi_cpu_stop+0x0/0x140 <- __stop_cpus.constprop.0+0x6f/0xb0 > > > > > > > > [ 24.374723] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > > > > > [ 24.374734] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > > > > > [ 24.374764] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > > > > > [ 24.374775] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > > > > > [ 24.374790] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > > > > > [ 24.374801] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > > > > > [ 24.374813] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > > > > > [ 24.374825] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > > > > > [ 24.374837] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > > > > > [ 24.374850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > > > > [ 24.374860] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > > > > > [ 24.374873] PKRU: 00000000 > > > > > > > > [ 24.374877] Call Trace: > > > > > > > > [ 24.374884] <TASK> > > > > > > > > [ 24.374891] ? __pfx_multi_cpu_stop+0x10/0x10 > > > > > > > > [ 24.374900] cpu_stopper_thread+0xa3/0x170 > > > > > > > > [ 24.374908] ? __pfx_smpboot_thread_fn+0x10/0x10 > > > > > > > > [ 24.374917] smpboot_thread_fn+0xf3/0x220 > > > > > > > > [ 24.374925] kthread+0xfc/0x240 > > > > > > > > [ 24.374933] ? __pfx_kthread+0x10/0x10 > > > > > > > > [ 24.374940] ? __pfx_kthread+0x10/0x10 > > > > > > > > [ 24.374949] ret_from_fork+0x158/0x170 > > > > > > > > [ 24.374957] ? __pfx_kthread+0x10/0x10 > > > > > > > > [ 24.374965] ret_from_fork_asm+0x1a/0x30 > > > > > > > > [ 24.374973] </TASK> > > > > > > > > [ 24.374978] Modules linked in: snd_seq_dummy snd_hrtimer snd_seq snd_seq_device snd_timer snd soundcore cfg80211 rfkill vfat fat xenfs binfmt_misc nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables intel_rapl_msr intel_rapl_common intel_uncore_frequency_common intel_pmc_ssram_telemetry intel_vsec polyval_clmulni ghash_clmulni_intel xen_netfront xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn fuse loop nfnetlink ip_tables overlay xen_blkfront > > > > > > > > [ 24.375064] CR2: 0000000000000020 > > > > > > > > [ 24.375071] ---[ end trace 0000000000000000 ]--- > > > > > > > > [ 24.375080] RIP: 0010:multi_cpu_stop+0x63/0x140 > > > > > > > > [ 24.375089] Code: 49 0f a3 1c 24 41 0f 92 c6 c7 44 24 04 00 00 00 00 31 ed 49 8d 5f 24 eb 2d 41 83 fd 02 74 6e 41 83 fd 03 74 49 f0 ff 0b 75 13 <41> 8b 47 20 41 8b 77 10 83 c0 01 41 89 77 24 41 89 47 20 41 83 fd > > > > > > > > [ 24.375115] RSP: 0018:ffffc900000abe30 EFLAGS: 00010046 > > > > > > > > [ 24.375124] RAX: 0000000000000000 RBX: ffffc90000a13de4 RCX: 0000000000000404 > > > > > > > > [ 24.375142] RDX: 0000000000000040 RSI: ffffffffffffffff RDI: 0000000000770ef0 > > > > > > > > [ 24.375155] RBP: 0000000000000002 R08: ffffc900000abc80 R09: ffffc900000abc8c > > > > > > > > [ 24.375170] R10: 0000000000000000 R11: ffff88801e81cdc0 R12: ffffffff81835ac0 > > > > > > > > [ 24.375184] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > > > > > > > > [ 24.375200] FS: 0000000000000000(0000) GS:ffff88809b369000(0000) knlGS:0000000000000000 > > > > > > > > [ 24.375214] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > > > > [ 24.375226] CR2: 0000000000000020 CR3: 000000000d6a2002 CR4: 0000000000770ef0 > > > > > > > > [ 24.375241] PKRU: 00000000 > > > > > > > > [ 24.375247] Kernel panic - not syncing: Fatal exception > > > > > > > > [ 25.417403] Shutting down cpus with NMI > > > > > > > > [ 25.417447] Kernel Offset: disabled > > > > > > > > > > > > > > > > There is no change on the Linux kernel side (neither dom0 nor domU), the > > > > > > > > only change is updating Xen 4.19.4 -> 4.22-rc2 (seems to be already > > > > > > > > broken on -rc1 too). This happens for both HVM and PVH domains. Haven't > > > > > > > > tried PV domU (but dom0 survives host suspend). > > > > > > > > > > > > > > Any ideas? > > > > > > > > > > > > > > > > > > > Hi, > > > > > > not many ideas but while testing my libxenguest changes I found > > > > > > similar failures using xl create/save/restore. But I was testing more > > > > > > PV guests. > > > > > > Does 4.21 work ? > > > > > > > > > > It seems 4.21 also has this issue: > > > > > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414211523 > > > > > But 4.20 is okay: > > > > > https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/15414227095 > > > > > > > > > > I guess I can bisect it further. > > > > > > > > So, bisect says the first bad commit is: > > > > > > > > commit 9f892f84c27970840d255aef7e2851b762967de7 > > > > Author: Andrew Cooper <andrew.cooper3@citrix.com> > > > > Date: Mon Dec 30 11:49:14 2024 +0000 > > > > > > > > x86/domctl: Stop using XLAT_cpu_user_regs() > > > > > > > > My test isn't 100% reliable, but I retested parent of this commit a > > > > couple of times and it was good every time. > > > > > > > > I wanted to test reverting it on top of 4.21, but there is a lot of > > > > FRED-related work on top that makes such revert quite hard, to say the > > > > least... > > > > > > > > > > The generated XLAT_cpu_user_regs was > > > > > > #define XLAT_cpu_user_regs(_d_, _s_) do { \ > > > (_d_)->__DECL_REG_LO8(b) = (_s_)->__DECL_REG_LO8(b); \ > > > (_d_)->__DECL_REG_LO8(c) = (_s_)->__DECL_REG_LO8(c); \ > > > (_d_)->__DECL_REG_LO8(d) = (_s_)->__DECL_REG_LO8(d); \ > > > (_d_)->__DECL_REG_LO16(si) = (_s_)->__DECL_REG_LO16(si); \ > > > (_d_)->__DECL_REG_LO16(di) = (_s_)->__DECL_REG_LO16(di); \ > > > (_d_)->__DECL_REG_LO16(bp) = (_s_)->__DECL_REG_LO16(bp); \ > > > (_d_)->__DECL_REG_LO8(a) = (_s_)->__DECL_REG_LO8(a); \ > > > (_d_)->error_code = (_s_)->error_code; \ > > > (_d_)->entry_vector = (_s_)->entry_vector; \ > > > (_d_)->__DECL_REG_LO16(ip) = (_s_)->__DECL_REG_LO16(ip); \ > > > (_d_)->cs = (_s_)->cs; \ > > > (_d_)->saved_upcall_mask = (_s_)->saved_upcall_mask; \ > > > (_d_)->__DECL_REG_LO16(flags) = (_s_)->__DECL_REG_LO16(flags); \ > > > (_d_)->__DECL_REG_LO16(sp) = (_s_)->__DECL_REG_LO16(sp); \ > > > (_d_)->ss = (_s_)->ss; \ > > > (_d_)->es = (_s_)->es; \ > > > (_d_)->ds = (_s_)->ds; \ > > > (_d_)->fs = (_s_)->fs; \ > > > (_d_)->gs = (_s_)->gs; \ > > > } while (0) > > > > > > registers are copied, but additional fields (error_code, entry_vector, > > > saved_upcall_mask). > > > Maybe you could try to copy them again. > > > Also, just to be on the safe side, you could memset the structure > > > where "Backing memory is pre-zeroed" comments are. > > > > This does not help :( > > > > Specifically: > > 1. Applied on top of staging-4.21: > > - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/188ca612c51a57ef54b917c833eaeb59666994c9 > > - test (fails): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688813821 > > 2. Applied directly on top of 9f892f84c27970840d255aef7e2851b762967de7: > > - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/dd3dee35fc4fcd6ba284f3f5fa78b333c472888e > > - test (fails): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688832398 > > > > Yet, parent of 9f892f84c27970840d255aef7e2851b762967de7 still passes: > > - build: https://gitlab.com/xen-project/people/marmarek/xen/-/commits/dbcbbed4e9dc25faa211d359c2f04a9c70f087c9 > > - test (pass): https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2688835512 > > > > Hint about reading the above: I use two branches, one for building > > (branch "test") and one for running the test (branch "automation-uki-grub-only"), > > which takes build artifacts from the build branch. I do that to not > > rebase test scripts. It's a bit opaque, but the console log of the test > > contains "Latest ChangeSet" fields telling what actually was tested. > > > > If it does not take long to test you could revert hunk by hunk > starting from xen/include/xlat.lst. Ok, I found what is wrong. It isn't about XLAT branch, but the native one, x86_64 has a couple more registers... This fixes it: diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c index 9af833b6da59f66d58eac3369c30a89919d0d805..893ebaa13a6f934e1af026f9eb13b1d18f746214 100644 --- a/xen/arch/x86/domain.c +++ b/xen/arch/x86/domain.c @@ -1280,6 +1280,14 @@ int arch_set_info_guest( if ( !compat ) { + v->arch.user_regs.r15 = c.nat->user_regs.r15; + v->arch.user_regs.r14 = c.nat->user_regs.r14; + v->arch.user_regs.r13 = c.nat->user_regs.r13; + v->arch.user_regs.r12 = c.nat->user_regs.r12; + v->arch.user_regs.r11 = c.nat->user_regs.r11; + v->arch.user_regs.r10 = c.nat->user_regs.r10; + v->arch.user_regs.r9 = c.nat->user_regs.r9; + v->arch.user_regs.r8 = c.nat->user_regs.r8; v->arch.user_regs.rbx = c.nat->user_regs.rbx; v->arch.user_regs.rcx = c.nat->user_regs.rcx; v->arch.user_regs.rdx = c.nat->user_regs.rdx; diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c index b8bc0caaf205828f9254e03584709482f3ba38a6..40f4cb049ce3f84ef38a604254392548a41342de 100644 --- a/xen/arch/x86/domctl.c +++ b/xen/arch/x86/domctl.c @@ -1440,6 +1440,14 @@ void arch_get_info_guest(struct vcpu *v, vcpu_guest_context_u c) if ( !compat ) { /* Backing memory is pre-zeroed. */ + c.nat->user_regs.r15 = v->arch.user_regs.r15; + c.nat->user_regs.r14 = v->arch.user_regs.r14; + c.nat->user_regs.r13 = v->arch.user_regs.r13; + c.nat->user_regs.r12 = v->arch.user_regs.r12; + c.nat->user_regs.r11 = v->arch.user_regs.r11; + c.nat->user_regs.r10 = v->arch.user_regs.r10; + c.nat->user_regs.r9 = v->arch.user_regs.r9; + c.nat->user_regs.r8 = v->arch.user_regs.r8; c.nat->user_regs.rbx = v->arch.user_regs.rbx; c.nat->user_regs.rcx = v->arch.user_regs.rcx; c.nat->user_regs.rdx = v->arch.user_regs.rdx; -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --] ^ permalink raw reply related [flat|nested] 10+ messages in thread
end of thread, other threads:[~2026-07-19 22:51 UTC | newest] Thread overview: 10+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-06-19 11:24 domU crash when resuming from suspend - Xen 4.22 Marek Marczykowski-Górecki 2026-07-14 17:12 ` Marek Marczykowski-Górecki 2026-07-15 6:16 ` Jan Beulich 2026-07-17 20:22 ` Frediano Ziglio 2026-07-18 14:03 ` Marek Marczykowski-Górecki 2026-07-19 1:59 ` Marek Marczykowski-Górecki 2026-07-19 7:31 ` Frediano Ziglio 2026-07-19 19:40 ` Marek Marczykowski-Górecki 2026-07-19 21:04 ` Frediano Ziglio 2026-07-19 22:50 ` Marek Marczykowski-Górecki
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