xen-3.0-x86_32p capability missing

[Frank Schiebel <frank.schiebel@xxxxxxxxxxxxxxxxxxxxxx>]

Hello,

I'm having an issue running 32bit DomUs on my freshly installed debian 
bullseye xen 4.14 installation.
I am unable to create any 32bit PV DomUs, I always get the following error:

> xc: error: panic: xc_dom_boot.c:120: xc_dom_boot_mem_init: can't allocate low 
> memory for domain: Out of memory
> libxl: error: libxl_dom.c:593:libxl__build_dom: xc_dom_boot_mem_init failed: 
> Operation not supported
After reconsidering the situation it turns out, that the capability for 
running 32bit PAE VMs is not present:
> host                   : toothless
> release                : 5.10.0-9-amd64
> version                : #1 SMP Debian 5.10.70-1 (2021-09-30)
> machine                : x86_64
> nr_cpus                : 4
> max_cpu_id             : 3
> nr_nodes               : 1
> cores_per_socket       : 2
> threads_per_core       : 2
> cpu_mhz                : 2893.316
> hw_caps                : 
> bfebfbff:76daf3bf:2c100800:00000021:00000001:000027ab:00000000:00000100
> virt_caps              : pv hvm hap shadow
> total_memory           : 16299
> free_memory            : 12010
> sharing_freed_memory   : 0
> sharing_used_memory    : 0
> outstanding_claims     : 0
> free_cpus              : 0
> xen_major              : 4
> xen_minor              : 14
> xen_extra              : .3
> xen_version            : 4.14.3
> xen_caps               : xen-3.0-x86_64 hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 
> xen_scheduler          : credit2
> xen_pagesize           : 4096
> platform_params        : virt_start=0xffff800000000000
> xen_changeset          : 
> xen_commandline        : placeholder dom0_mem=1024M,max:1024M smt=true
> cc_compiler            : x86_64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110
> cc_compile_by          : pkg-xen-devel
> cc_compile_domain      : lists.alioth.debian.org
> cc_compile_date        : Mon Sep 13 14:28:21 UTC 2021
> build_id               : 1a67c53a8813b422d2033de494f8b444915791f2
> xend_config_format     : 4
The capability "xen-3.0-x86_32p" is not listed?

I think I am missing something rather emelentary, but am unable to 
figure out what - so any help would be greatly appreciated.
TIA

Frank

This is the Output of "xl dmesg":

> root@toothless:~# xl dmesg
> (XEN) Xen version 4.14.3 (Debian 4.14.3-1~deb11u1) 
> (pkg-xen-devel@xxxxxxxxxxxxxxxxxxxxxxx) (x86_64-linux-gnu-gcc (Debian 10.2.1-6) 
> 10.2.1 20210110) debug=n  Mon Sep 13 14:28:21 UTC 2021
> (XEN) Bootloader: GRUB 2.04-20
> (XEN) Command line: placeholder dom0_mem=1024M,max:1024M smt=true
> (XEN) Xen image load base address: 0xdac00000
> (XEN) Video information:
> (XEN)  VGA is text mode 80x25, font 8x16
> (XEN)  VBE/DDC methods: V2; EDID transfer time: 1 seconds
> (XEN) Disc information:
> (XEN)  Found 4 MBR signatures
> (XEN)  Found 4 EDD information structures
> (XEN) Xen-e820 RAM map:
> (XEN)  [0000000000000000, 000000000009d7ff] (usable)
> (XEN)  [000000000009d800, 000000000009ffff] (reserved)
> (XEN)  [00000000000e0000, 00000000000fffff] (reserved)
> (XEN)  [0000000000100000, 00000000c889ffff] (usable)
> (XEN)  [00000000c88a0000, 00000000c88a6fff] (ACPI NVS)
> (XEN)  [00000000c88a7000, 00000000c970efff] (usable)
> (XEN)  [00000000c970f000, 00000000c9cd5fff] (reserved)
> (XEN)  [00000000c9cd6000, 00000000db334fff] (usable)
> (XEN)  [00000000db335000, 00000000db3befff] (reserved)
> (XEN)  [00000000db3bf000, 00000000db3d4fff] (ACPI data)
> (XEN)  [00000000db3d5000, 00000000db542fff] (ACPI NVS)
> (XEN)  [00000000db543000, 00000000dbffefff] (reserved)
> (XEN)  [00000000dbfff000, 00000000dbffffff] (usable)
> (XEN)  [00000000dd000000, 00000000df1fffff] (reserved)
> (XEN)  [00000000f8000000, 00000000fbffffff] (reserved)
> (XEN)  [00000000fec00000, 00000000fec00fff] (reserved)
> (XEN)  [00000000fed00000, 00000000fed03fff] (reserved)
> (XEN)  [00000000fed1c000, 00000000fed1ffff] (reserved)
> (XEN)  [00000000fee00000, 00000000fee00fff] (reserved)
> (XEN)  [00000000ff000000, 00000000ffffffff] (reserved)
> (XEN)  [0000000100000000, 000000041fdfffff] (usable)
> (XEN) ACPI: RSDP 000F0490, 0024 (r2  INTEL)
> (XEN) ACPI: XSDT DB3C3080, 007C (r1 INTEL  DH87RL        144 AMI     10013)
> (XEN) ACPI: FACP DB3CFCA8, 010C (r5 INTEL  DH87RL        144 AMI     10013)
> (XEN) ACPI: DSDT DB3C3188, CB1F (r2 INTEL  DH87RL        144 INTL 20120711)
> (XEN) ACPI: FACS DB541080, 0040
> (XEN) ACPI: APIC DB3CFDB8, 0072 (r3 INTEL  DH87RL        144 AMI     10013)
> (XEN) ACPI: FPDT DB3CFE30, 0044 (r1 INTEL  DH87RL        144 AMI     10013)
> (XEN) ACPI: LPIT DB3CFE78, 005C (r1 INTEL  DH87RL        144 AMI.        5)
> (XEN) ACPI: SSDT DB3CFED8, 0539 (r1 INTEL  DH87RL        144 INTL 20120711)
> (XEN) ACPI: SSDT DB3D0418, 0AD8 (r1 INTEL  DH87RL        144 INTL 20120711)
> (XEN) ACPI: SSDT DB3D0EF0, 01C7 (r1 INTEL  DH87RL        144 INTL 20120711)
> (XEN) ACPI: MCFG DB3D10B8, 003C (r1 INTEL  DH87RL        144 MSFT       97)
> (XEN) ACPI: HPET DB3D10F8, 0038 (r1 INTEL  DH87RL        144 AMI.        5)
> (XEN) ACPI: SSDT DB3D1130, 036D (r1 INTEL  DH87RL        144 INTL 20120711)
> (XEN) ACPI: SSDT DB3D14A0, 3004 (r1 INTEL  DH87RL        144 INTL 20091112)
> (XEN) System RAM: 16299MB (16690196kB)
> (XEN) Domain heap initialised
> (XEN) ACPI: 32/64X FACS address mismatch in FADT - db541080/0000000000000000, 
> using 32
> (XEN) IOAPIC[0]: apic_id 2, version 32, address 0xfec00000, GSI 0-23
> (XEN) Enabling APIC mode:  Flat.  Using 1 I/O APICs
> (XEN) CPU0: 800 ... 2900 MHz
> (XEN) xstate: size: 0x340 and states: 0x7
> (XEN) Speculative mitigation facilities:
> (XEN)   Hardware features:
> (XEN)   Compiled-in support: INDIRECT_THUNK SHADOW_PAGING
> (XEN)   Xen settings: BTI-Thunk RETPOLINE, SPEC_CTRL: No, Other: BRANCH_HARDEN
> (XEN)   L1TF: believed vulnerable, maxphysaddr L1D 46, CPUID 39, Safe address 
> 8000000000
> (XEN)   Support for HVM VMs: RSB EAGER_FPU
> (XEN)   Support for PV VMs: RSB EAGER_FPU
> (XEN)   XPTI (64-bit PV only): Dom0 enabled, DomU enabled (with PCID)
> (XEN)   PV L1TF shadowing: Dom0 disabled, DomU enabled
> (XEN) Using scheduler: SMP Credit Scheduler rev2 (credit2)
> (XEN) Initializing Credit2 scheduler
> (XEN) Platform timer is 14.318MHz HPET
> (XEN) Detected 2893.316 MHz processor.
> (XEN) I/O virtualisation disabled
> (XEN) Enabled directed EOI with ioapic_ack_old on!
> (XEN) ENABLING IO-APIC IRQs
> (XEN)  -> Using old ACK method
> (XEN) TSC_DEADLINE disabled due to Errata; please update microcode to version 
> 0x22 (or later)
> (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) 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 4 CPUs
> (XEN) Scheduling granularity: cpu, 1 CPU per sched-resource
> (XEN) Dom0 has maximum 648 PIRQs
> (XEN)  Xen  kernel: 64-bit, lsb, compat32
> (XEN)  Dom0 kernel: 64-bit, PAE, lsb, paddr 0x1000000 -> 0x322c000
> (XEN) PHYSICAL MEMORY ARRANGEMENT:
> (XEN)  Dom0 alloc.:   0000000408000000->000000040c000000 (237439 pages to be 
> allocated)
> (XEN)  Init. ramdisk: 000000041dd7f000->000000041fdffd0b
> (XEN) VIRTUAL MEMORY ARRANGEMENT:
> (XEN)  Loaded kernel: ffffffff81000000->ffffffff8322c000
> (XEN)  Init. ramdisk: 0000000000000000->0000000000000000
> (XEN)  Phys-Mach map: 0000008000000000->0000008000200000
> (XEN)  Start info:    ffffffff8322c000->ffffffff8322c4b8
> (XEN)  Xenstore ring: 0000000000000000->0000000000000000
> (XEN)  Console ring:  0000000000000000->0000000000000000
> (XEN)  Page tables:   ffffffff8322d000->ffffffff8324a000
> (XEN)  Boot stack:    ffffffff8324a000->ffffffff8324b000
> (XEN)  TOTAL:         ffffffff80000000->ffffffff83400000
> (XEN)  ENTRY ADDRESS: ffffffff82c31160
> (XEN) Dom0 has maximum 4 VCPUs
> (XEN) Initial low memory virq threshold set at 0x4000 pages.
> (XEN) Scrubbing Free RAM in background
> (XEN) Std. Loglevel: Errors and warnings
> (XEN) Guest Loglevel: Nothing (Rate-limited: Errors and warnings)
> (XEN) Xen is relinquishing VGA console.
> (XEN) *** Serial input to DOM0 (type 'CTRL-a' three times to switch input)
> (XEN) Freed 552kB init memory