nvidia 418.56, Fedora 29, dual nvidia graphics cards crashes with kernel 5.x on boot

Hi,

Since upgrading to kernel 5.0.5 my machine crashes on boot after loading Nvidia graphics driver.

The same machine boots without any problems with kernel 4.20.16.

Apr 09 08:45:21 kernel: NVRM: loading NVIDIA UNIX x86_64 Kernel Module 418.56 Fri Mar 15 12:59:26 CDT 2019
Apr 09 08:45:21 kernel: nvidia-uvm: Loaded the UVM driver in 8 mode, major device number 234
Apr 09 08:45:21 kernel: nvidia-modeset: Loading NVIDIA Kernel Mode Setting Driver for UNIX platforms 418.56 Fri Mar 15 12:32:40 CDT 2019
Apr 09 08:45:21 kernel: [drm] [nvidia-drm] [GPU ID 0x00000100] Loading driver
Apr 09 08:45:21 kernel: [drm] Initialized nvidia-drm 0.0.0 20160202 for 0000:01:00.0 on minor 0
Apr 09 08:45:21 kernel: [drm] [nvidia-drm] [GPU ID 0x00000500] Loading driver
Apr 09 08:45:21 kernel: [drm] Initialized nvidia-drm 0.0.0 20160202 for 0000:05:00.0 on minor 1
.
.
Apr 09 08:45:38 kernel: BUG: unable to handle kernel NULL pointer dereference at 0000000000000040
Apr 09 08:45:38 kernel: #PF error: [normal kernel read fault]
Apr 09 08:45:38 kernel: PGD 0 P4D 0
Apr 09 08:45:38 kernel: Oops: 0000 [#1] SMP PTI
Apr 09 08:45:38 kernel: CPU: 1 PID: 1560 Comm: Xorg Tainted: P OE 5.0.5-200.fc29.x86_64 #1
Apr 09 08:45:38 kernel: RIP: 0010:nv_dma_map_peer+0xd0/0x160 [nvidia]
Apr 09 08:45:38 kernel: Code: ce e8 b4 fd ff ff 48 8b 5c 24 10 65 48 33 1c 25 28 00 00 00 0f 85 8e 00 00 00 48 83 c4 18 5b 5d 41 5c c3 48 8b 05 c0 ed 12 cc <48> 83 78 40 00 75 ca 49 c1 e2 06 49 8b 78 10 48 89 e6 4b 8d 94 10
Apr 09 08:45:38 kernel: RSP: 0018:ffffb1fdc82ef950 EFLAGS: 00010246
Apr 09 08:45:38 kernel: RAX: 0000000000000000 RBX: ffff90552c1c8ff0 RCX: 0000000000000010
Apr 09 08:45:38 kernel: RDX: 0000000000000001 RSI: ffff90555993e000 RDI: ffff905554581800
Apr 09 08:45:38 kernel: RBP: 00000000c0000000 R08: ffff9055594c1000 R09: 00000000cfffffff
Apr 09 08:45:38 kernel: R10: 0000000000000001 R11: 0000000000010000 R12: 00000000c0000000
Apr 09 08:45:38 kernel: R13: ffff90555993e000 R14: 0000000054581800 R15: ffff90552c1c8fc8
Apr 09 08:45:38 kernel: FS: 00007ff0eaaa5ac0(0000) GS:ffff90555da40000(0000) knlGS:0000000000000000
Apr 09 08:45:38 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Apr 09 08:45:38 kernel: CR2: 0000000000000040 CR3: 00000008178dc002 CR4: 00000000001606e0
Apr 09 08:45:38 kernel: Call Trace:
Apr 09 08:45:38 kernel: _nv029599rm+0x265/0x490 [nvidia]
Apr 09 08:45:38 kernel: ? _nv025113rm+0x17c/0x3f0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv026023rm+0xd7/0x270 [nvidia]
Apr 09 08:45:38 kernel: ? _nv010048rm+0x122/0x1b0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv010043rm+0xc7/0x300 [nvidia]
Apr 09 08:45:38 kernel: ? _nv010059rm+0x286/0x2d0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv020288rm+0x72/0x1e0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv020287rm+0x8cd/0xa40 [nvidia]
Apr 09 08:45:38 kernel: ? _nv006779rm+0x47/0xc0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv020527rm+0x315/0x610 [nvidia]
Apr 09 08:45:38 kernel: ? _nv020429rm+0x149/0x1a0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv020566rm+0x84/0x150 [nvidia]
Apr 09 08:45:38 kernel: ? _nv020567rm+0x218/0x6c0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv026582rm+0x1da/0x280 [nvidia]
Apr 09 08:45:38 kernel: ? _nv032643rm+0x13a/0x1a0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv007920rm+0x111/0x1c0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv007923rm+0x37f/0x3b0 [nvidia]
Apr 09 08:45:38 kernel: ? _nv032740rm+0x57/0x100 [nvidia]
Apr 09 08:45:38 kernel: ? _nv032740rm+0x37/0x100 [nvidia]
Apr 09 08:45:38 kernel: ? _nv007023rm+0x38/0x50 [nvidia]
Apr 09 08:45:38 kernel: ? _nv007023rm+0x19/0x50 [nvidia]
Apr 09 08:45:38 kernel: ? _nv000697rm+0x27/0x30 [nvidia]
Apr 09 08:45:38 kernel: ? _nv000935rm+0x4f9/0x900 [nvidia]
Apr 09 08:45:38 kernel: ? rm_ioctl+0x54/0xb0 [nvidia]
Apr 09 08:45:38 kernel: ? nvidia_ioctl+0x51/0x7c0 [nvidia]
Apr 09 08:45:38 kernel: ? nvidia_ioctl+0x5fa/0x7c0 [nvidia]
Apr 09 08:45:38 kernel: ? nvidia_frontend_unlocked_ioctl+0x3a/0x50 [nvidia]
Apr 09 08:45:38 kernel: ? do_vfs_ioctl+0xa4/0x630
Apr 09 08:45:38 kernel: ? set_close_on_exec+0x2a/0x60
Apr 09 08:45:38 kernel: ? do_fcntl+0x524/0x610
Apr 09 08:45:38 kernel: ? kmem_cache_free+0x1b1/0x1e0
Apr 09 08:45:38 kernel: ? ksys_ioctl+0x60/0x90
Apr 09 08:45:38 kernel: ? __x64_sys_fcntl+0x8b/0xb0
Apr 09 08:45:38 kernel: ? __x64_sys_ioctl+0x16/0x20
Apr 09 08:45:38 kernel: ? do_syscall_64+0x5b/0x160
Apr 09 08:45:38 kernel: ? entry_SYSCALL_64_after_hwframe+0x44/0xa9
Apr 09 08:45:38 kernel: Modules linked in: iptable_mangle xt_CHECKSUM iptable_nat ipt_MASQUERADE nf_nat_ipv4 nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c tun bridge stp llc devlink ebtable_filter ebtables ip6table_filter ip6_tables vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) sunrpc mei_wdt nvidia_drm(POE) nvidia_modeset(POE) nvidia_uvm(OE) nvidia(POE) intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass snd_hda_codec_hdmi joydev snd_hda_codec_realtek snd_hda_codec_generic eeprom ledtrig_audio iTCO_wdt iTCO_vendor_support snd_hda_intel snd_hda_codec crct10dif_pclmul crc32_pclmul snd_hda_core dell_smm_hwmon snd_hwdep snd_seq ghash_clmulni_intel intel_cstate snd_seq_device drm_kms_helper intel_uncore snd_pcm intel_rapl_perf drm dell_wmi dell_smbios wmi_bmof intel_wmi_thunderbolt i2c_i801 dcdbas sparse_keymap snd_timer dell_wmi_descriptor snd ipmi_devintf mei_me ipmi_msghandler lpc_ich mei soundcore pcc_cpufreq binfmt_misc uas usb_storage
Apr 09 08:45:38 kernel: e1000e crc32c_intel wmi video i2c_dev
Apr 09 08:45:38 kernel: CR2: 0000000000000040
Apr 09 08:45:38 kernel: —[ end trace e057721395587ebb ]—

$ lspci | grep -i nvidia
01:00.0 VGA compatible controller: NVIDIA Corporation GK107GL [Quadro K420] (rev a1)
01:00.1 Audio device: NVIDIA Corporation GK107 HDMI Audio Controller (rev a1)
05:00.0 VGA compatible controller: NVIDIA Corporation GK107GL [Quadro K420] (rev a1)
05:00.1 Audio device: NVIDIA Corporation GK107 HDMI Audio Controller (rev a1)

Regards,

Multi-gpu setups are currently broken with kernel 5.x
https://devtalk.nvidia.com/default/topic/1048320/linux/arch-linux-not-booting-anymore-using-418-43-5-with-x-server-1-20-4-1/post/5320077/#5320077