Kernel 4.15 boot error on XenServer

I recently upgraded an ubuntu VM from 16.04.1 to 18.04.1 running on XenServer 7.1. The upgrade itself was fine, but several kernel updates after the upgrade have caused the VM to fail to boot. All kernels that fail to boot seem to be from 4.15. Current, the latest kernel I've tried is 4.15.0-38, though, day-to-day I'm running a 4.4 kernel since the VM is necessary to my environment.

The error message on boot is:
unchecked MSR access error: RDMSR from 0xc90 at rIP: 0xffffffff9806c04a (native_read_msr+0xa/0x30)

The trace is attached as a screenshot. I haven't been able to get a log containing the output.

user@host:~$ cat /proc/version_signature
Ubuntu 4.4.0-112.135-generic 4.4.98

user@host:~$ sudo lspci -vnvn
00:00.0 Host bridge [0600]: Intel Corporation 440FX - 82441FX PMC [Natoma] [8086:1237] (rev 02)
        Subsystem: Red Hat, Inc Qemu virtual machine [1af4:1100]
        Physical Slot: 0
        Control: I/O- Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0

00:01.0 ISA bridge [0601]: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II] [8086:7000]
        Subsystem: Red Hat, Inc Qemu virtual machine [1af4:1100]
        Physical Slot: 1
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0

00:01.1 IDE interface [0101]: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II] [8086:7010] (prog-if 80 [Master])
        Subsystem: XenSource, Inc. 82371SB PIIX3 IDE [Natoma/Triton II] [5853:0001]
        Physical Slot: 1
        Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 64
        Region 0: [virtual] Memory at 000001f0 (32-bit, non-prefetchable) [size=8]
        Region 1: [virtual] Memory at 000003f0 (type 3, non-prefetchable)
        Region 2: [virtual] Memory at 00000170 (32-bit, non-prefetchable) [size=8]
        Region 3: [virtual] Memory at 00000370 (type 3, non-prefetchable)
        Region 4: I/O ports at c320 [size=16]
        Kernel driver in use: ata_piix
        Kernel modules: pata_acpi

00:01.2 USB controller [0c03]: Intel Corporation 82371SB PIIX3 USB [Natoma/Triton II] [8086:7020] (rev 01) (prog-if 00 [UHCI])
        Subsystem: XenSource, Inc. 82371SB PIIX3 USB [Natoma/Triton II] [5853:0001]
        Physical Slot: 1
        Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 64
        Interrupt: pin D routed to IRQ 23
        Region 4: I/O ports at c300 [size=32]
        Kernel driver in use: uhci_hcd

00:01.3 Bridge [0680]: Intel Corporation 82371AB/EB/MB PIIX4 ACPI [8086:7113] (rev 01)
        Subsystem: Red Hat, Inc Qemu virtual machine [1af4:1100]
        Physical Slot: 1
        Control: I/O- Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0
        Interrupt: pin A routed to IRQ 9
        Kernel modules: i2c_piix4

00:02.0 VGA compatible controller [0300]: Device [1234:1111] (prog-if 00 [VGA controller])
        Subsystem: XenSource, Inc. Device [5853:0001]
        Physical Slot: 2
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0
        Region 0: Memory at f1000000 (32-bit, prefetchable) [size=8M]
        Expansion ROM at <unassigned> [disabled]

00:03.0 SCSI storage controller [0100]: XenSource, Inc. Xen Platform Device [5853:0001] (rev 02)
        Subsystem: XenSource, Inc. Xen Platform Device [5853:0001]
        Physical Slot: 3
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0
        Interrupt: pin C routed to IRQ 30
        Region 0: I/O ports at c000 [size=256]
        Region 1: Memory at f0000000 (32-bit, prefetchable) [size=16M]
        Kernel driver in use: xen-platform-pci