Hi! I've been working on a Windows 10 HVM on a Debian 10 dom0. When I was first trying to make the VM, I was getting IOMMU errors. I had a hard time figuring out what to do about this, and finally discovered that putting iommu=no-igfx in the grub stopped the errors.
Unfortunately, without the graphics support the VM is understandably slow, and can crash. I was also only now pointed to the page <https://xenbits.xen.org/docs/unstable/misc/xen-command-line.html#iommu> which says to report any errors that get fixed by using iommu=no-igfx. I'm attaching a copy of xl dmesg from before I put in the no-igfx. The bottom is the iommu errors. If there is a better way for me to share the output, please let me know.
(XEN) parameter "placeholder" unknown! (XEN) parameter "no-real-mode" unknown! (XEN) parameter "edd" unknown! (XEN) Xen version 4.11.4-pre (Debian 4.11.3+24-g14b62ab3e5-1~deb10u1) (pkg-xen-de...@lists.alioth.debian.org) (gcc (Debian 8.3.0-6) 8.3.0) debug=n Wed Jan 8 20:16:51 UTC 2020 (XEN) Bootloader: GRUB 2.02+dfsg1-20 (XEN) Command line: placeholder no-real-mode edd=off (XEN) Xen image load base address: 0x7be00000 (XEN) Video information: (XEN) VGA is graphics mode 1920x1080, 32 bpp (XEN) Disc information: (XEN) Found 0 MBR signatures (XEN) Found 1 EDD information structures (XEN) EFI RAM map: (XEN) 0000000000000000 - 000000000009f000 (usable) (XEN) 000000000009f000 - 0000000000100000 (reserved) (XEN) 0000000000100000 - 000000007ccba000 (usable) (XEN) 000000007ccba000 - 000000007fbe7000 (reserved) (XEN) 000000007fbe7000 - 000000007fcaa000 (ACPI NVS) (XEN) 000000007fcaa000 - 000000007fd0f000 (ACPI data) (XEN) 000000007fd0f000 - 000000007fd10000 (usable) (XEN) 000000007fd10000 - 0000000088000000 (reserved) (XEN) 0000000088000000 - 0000000088200000 (usable) (XEN) 0000000088200000 - 000000008c800000 (reserved) (XEN) 00000000fe010000 - 00000000fe011000 (reserved) (XEN) 0000000100000000 - 0000000871800000 (usable) (XEN) ACPI: RSDP 7FD0E014, 0024 (r2 LENOVO) (XEN) ACPI: XSDT 7FD0C188, 010C (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: FACP 7E9E6000, 0114 (r6 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: DSDT 7E9BE000, 2311B (r2 LENOVO CFL 20170001 INTL 20160422) (XEN) ACPI: FACS 7FC05000, 0040 (XEN) ACPI: SSDT 7EA93000, 1B1C (r2 LENOVO CpuSsdt 3000 INTL 20160527) (XEN) ACPI: SSDT 7EA92000, 056D (r2 LENOVO CtdpB 1000 INTL 20160527) (XEN) ACPI: SSDT 7EA59000, 3996 (r2 LENOVO DptfTabl 1000 INTL 20160527) (XEN) ACPI: SSDT 7E9EB000, 313D (r2 LENOVO SaSsdt 3000 INTL 20160527) (XEN) ACPI: SSDT 7E9EA000, 0612 (r2 LENOVO Tpm2Tabl 1000 INTL 20160527) (XEN) ACPI: TPM2 7E9E9000, 0034 (r4 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: UEFI 7FC1A000, 0042 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: SSDT 7E9E7000, 0538 (r2 LENOVO PerfTune 1000 INTL 20160527) (XEN) ACPI: HPET 7E9E5000, 0038 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: APIC 7E9E4000, 012C (r3 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: MCFG 7E9E3000, 003C (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: ECDT 7E9E2000, 0053 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: SSDT 7E9BB000, 2304 (r2 LENOVO ProjSsdt 10 INTL 20160527) (XEN) ACPI: BOOT 7E9BA000, 0028 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: SLIC 7E9B9000, 0176 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: SSDT 7E9B8000, 0CE3 (r2 LENOVO UsbCTabl 1000 INTL 20160527) (XEN) ACPI: LPIT 7E9B7000, 005C (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: WSMT 7E9B6000, 0028 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: SSDT 7E9B4000, 149F (r2 LENOVO TbtTypeC 0 INTL 20160527) (XEN) ACPI: DBGP 7E9B3000, 0034 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: DBG2 7E9B2000, 0054 (r0 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: MSDM 7E9B1000, 0055 (r3 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: BATB 7E99C000, 004A (r2 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: NHLT 7DB99000, 002D (r0 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: DMAR 7DB98000, 00A8 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: FPDT 7DB96000, 0044 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: BGRT 7DB95000, 0038 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) ACPI: UEFI 7FC00000, 0116 (r1 LENOVO TP-R0Y 1B0 PTEC 2) (XEN) System RAM: 32486MB (33266024kB) (XEN) Domain heap initialised (XEN) ACPI: Invalid sleep control/status register data: 0:0x8:0x3 0:0x8:0x3 (XEN) ACPI: 32/64X FACS address mismatch in FADT - 7fc05000/0000000000000000, using 32 (XEN) IOAPIC[0]: apic_id 2, version 32, address 0xfec00000, GSI 0-119 (XEN) Enabling APIC mode: Flat. Using 1 I/O APICs (XEN) Switched to APIC driver x2apic_cluster (XEN) xstate: size: 0x440 and states: 0x1f (XEN) Speculative mitigation facilities: (XEN) Hardware features: IBRS/IBPB STIBP L1D_FLUSH SSBD RDCL_NO SKIP_L1DFL (XEN) Compiled-in support: INDIRECT_THUNK SHADOW_PAGING (XEN) Xen settings: BTI-Thunk JMP, SPEC_CTRL: IBRS+ SSBD-, Other: IBPB (XEN) Support for VMs: PV: MSR_SPEC_CTRL RSB EAGER_FPU, HVM: MSR_SPEC_CTRL RSB EAGER_FPU (XEN) XPTI (64-bit PV only): Dom0 disabled, DomU disabled (XEN) PV L1TF shadowing: Dom0 disabled, DomU disabled (XEN) Using scheduler: SMP Credit Scheduler (credit) (XEN) Platform timer is 23.999MHz HPET (XEN) Detected 1992.103 MHz processor. (XEN) Initing memory sharing. (XEN) PCI: Not using MCFG for segment 0000 bus 00-ff (XEN) Intel VT-d iommu 0 supported page sizes: 4kB, 2MB, 1GB. (XEN) Intel VT-d iommu 1 supported page sizes: 4kB, 2MB, 1GB. (XEN) Intel VT-d Snoop Control not enabled. (XEN) Intel VT-d Dom0 DMA Passthrough not enabled. (XEN) Intel VT-d Queued Invalidation enabled. (XEN) Intel VT-d Interrupt Remapping enabled. (XEN) Intel VT-d Posted Interrupt not enabled. (XEN) Intel VT-d Shared EPT tables enabled. (XEN) I/O virtualisation enabled (XEN) - Dom0 mode: Relaxed (XEN) Interrupt remapping enabled (XEN) Enabled directed EOI with ioapic_ack_old on! (XEN) ENABLING IO-APIC IRQs (XEN) -> Using old ACK method (XEN) Allocated console ring of 16 KiB. (XEN) VMX: Supported advanced features: (XEN) - APIC MMIO access virtualisation (XEN) - APIC TPR shadow (XEN) - Extended Page Tables (EPT) (XEN) - Virtual-Processor Identifiers (VPID) (XEN) - Virtual NMI (XEN) - MSR direct-access bitmap (XEN) - Unrestricted Guest (XEN) - VM Functions (XEN) - Virtualisation Exceptions (XEN) - Page Modification Logging (XEN) HVM: ASIDs enabled. (XEN) VMX: Disabling executable EPT superpages due to CVE-2018-12207 (XEN) HVM: VMX enabled (XEN) HVM: Hardware Assisted Paging (HAP) detected (XEN) HVM: HAP page sizes: 4kB, 2MB, 1GB (XEN) Brought up 8 CPUs (XEN) Dom0 has maximum 888 PIRQs (XEN) Xen kernel: 64-bit, lsb, compat32 (XEN) Dom0 kernel: 64-bit, PAE, lsb, paddr 0x1000000 -> 0x282c000 (XEN) PHYSICAL MEMORY ARRANGEMENT: (XEN) Dom0 alloc.: 0000000850000000->0000000854000000 (8147267 pages to be allocated) (XEN) Init. ramdisk: 000000086f254000->00000008717ffd6c (XEN) VIRTUAL MEMORY ARRANGEMENT: (XEN) Loaded kernel: ffffffff81000000->ffffffff8282c000 (XEN) Init. ramdisk: 0000000000000000->0000000000000000 (XEN) Phys-Mach map: 0000008000000000->0000008003e5b778 (XEN) Start info: ffffffff8282c000->ffffffff8282c4b8 (XEN) Xenstore ring: 0000000000000000->0000000000000000 (XEN) Console ring: 0000000000000000->0000000000000000 (XEN) Page tables: ffffffff8282d000->ffffffff82846000 (XEN) Boot stack: ffffffff82846000->ffffffff82847000 (XEN) TOTAL: ffffffff80000000->ffffffff82c00000 (XEN) ENTRY ADDRESS: ffffffff82456180 (XEN) Dom0 has maximum 8 VCPUs (XEN) Initial low memory virq threshold set at 0x4000 pages. (XEN) Scrubbing Free RAM on 1 nodes using 4 CPUs (XEN) ....................................................................done. (XEN) Std. Loglevel: Errors and warnings (XEN) Guest Loglevel: Nothing (Rate-limited: Errors and warnings) (XEN) *************************************************** (XEN) Booted on MLPDS/MFBDS-vulnerable hardware with SMT/Hyperthreading (XEN) enabled. Mitigations will not be fully effective. Please (XEN) choose an explicit smt=<bool> setting. See XSA-297. (XEN) *************************************************** (XEN) 3... 2... 1... (XEN) Xen is relinquishing VGA console. (XEN) *** Serial input -> DOM0 (type 'CTRL-a' three times to switch input to Xen) (XEN) Freed 476kB init memory (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 76c615d000, iommu reg = ffff82c000a0c000 (XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 76c615d000, iommu reg = ffff82c000a0c000 (XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 76c615d000, iommu reg = ffff82c000a0c000 (XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 76c615d000, iommu reg = ffff82c000a0c000 (XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 76c615d000, iommu reg = ffff82c000a0c000 (XEN) [VT-D]DMAR: reason 06 - PTE Read access is not set (XEN) printk: 200 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 76c615d000, iommu reg = ffff82c000a0c000 (XEN) printk: 145 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 212ed69000, iommu reg = ffff82c000a0c000 (XEN) printk: 501 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 212ed69000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 212ed69000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 1f27d91000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 4f6eea4000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 7470ecb000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 4f6eea4000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 4f6eea4000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 4f6eea4000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 7470ecb000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 7470ecb000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 7470ecb000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 7470ecb000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 1f27d91000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 4f6eea4000, iommu reg = ffff82c000a0c000 (XEN) printk: 601 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 1f27d91000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 7470ecb000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 7470ecb000, iommu reg = ffff82c000a0c000 (XEN) printk: 599 messages suppressed. (XEN) [VT-D]DMAR:[DMA Read] Request device [0000:00:02.0] fault addr 1f27d91000, iommu reg = ffff82c000a0c000
