I use debian as xen dom0 and the cpu is Hygon C86 7360 24-core Processor. I found there is no any cpu cache detected in xen dom0, no matter L1/L2/L3 cpu cache,the same as hvm domU。But I use cpuid in
dom0, it can get the Cache Properties (0x8000001d). I wonder why cpuid can detect Cache Properties but guestOS can not detect cpu cache? Please give me some advise,Thanks!
The informations are show blow, and the all cpuid info and dom0 dmesg are in attachment.
Cache Properties (0x8000001d):
--- cache 0 ---
type = data (1)
level = 0x1 (1)
self-initializing = true
fully associative = false
extra cores sharing this cache = 0x0 (0)
line size in bytes = 0x40 (64)
physical line partitions = 0x1 (1)
number of ways = 0x8 (8)
number of sets = 64
write-back invalidate = false
cache inclusive of lower levels = false
(synth size) = 32768 (32 KB)
--- cache 1 ---
type = instruction (2)
level = 0x1 (1)
self-initializing = true
fully associative = false
extra cores sharing this cache = 0x0 (0)
line size in bytes = 0x40 (64)
physical line partitions = 0x1 (1)
number of ways = 0x4 (4)
number of sets = 256
write-back invalidate = false
cache inclusive of lower levels = false
(synth size) = 65536 (64 KB)
--- cache 2 ---
type = unified (3)
level = 0x2 (2)
self-initializing = true
fully associative = false
extra cores sharing this cache = 0x0 (0)
line size in bytes = 0x40 (64)
physical line partitions = 0x1 (1)
number of ways = 0x8 (8)
number of sets = 1024
write-back invalidate = false
cache inclusive of lower levels = true
(synth size) = 524288 (512 KB)
--- cache 3 ---
type = unified (3)
level = 0x3 (3)
self-initializing = true
fully associative = false
extra cores sharing this cache = 0x2 (2)
line size in bytes = 0x40 (64)
physical line partitions = 0x1 (1)
number of ways = 0x10 (16)
number of sets = 8192
write-back invalidate = true
cache inclusive of lower levels = false
(synth size) = 8388608 (8 MB)
$ sudo xl info
host : debian
release : 6.1.0-25-amd64
version : #1 SMP PREEMPT_DYNAMIC Debian 6.1.106-3 (2024-08-26)
machine : x86_64
nr_cpus : 24
max_cpu_id : 23
nr_nodes : 4
cores_per_socket : 24
threads_per_core : 1
cpu_mhz : 2200.002
hw_caps : 178bf3ff:36d8320b:2e500800:244033ff:0000000f:209801a9:00000000:00000780
virt_caps : pv hvm hvm_directio pv_directio hap shadow gnttab-v1 gnttab-v2
total_memory : 65453
free_memory : 50421
sharing_freed_memory : 0
sharing_used_memory : 0
outstanding_claims : 0
free_cpus : 0
xen_major : 4
xen_minor : 17
xen_extra : .5
xen_version : 4.17.5
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 : Tue Oct 22 03:55:32 2024 -0400 git:f1c1a10e76-dirty
xen_commandline : placeholder dom0_mem=4096M,max:4096M dom0_max_vcpus=4 loglvl=all guest_loglvl=all com1=115200,8n1 console=com1 dom0_vcpus_pin=true no-real-mode edd=off
cc_compiler : gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-22)
cc_compile_by : root
cc_compile_domain :
cc_compile_date : Sun Jan 5 22:22:05 EST 2025
build_id : f61e2b9e617c3b328bc10dbf361ed91d537ccf6c
xend_config_format : 4
$ sudo lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 43 bits physical, 48 bits virtual
Byte Order: Little Endian
CPU(s): 4
On-line CPU(s) list: 0-3
Vendor ID: HygonGenuine
BIOS Vendor ID: Chengdu Hygon
Model name: Hygon C86 7360 24-core Processor
BIOS Model name: Hygon C86 7360 24-core Processor CPU @ 2.2GHz
BIOS CPU family: 1
CPU family: 24
Model: 2
Thread(s) per core: 1
Core(s) per socket: 4
Socket(s): 1
Stepping: 2
BogoMIPS: 4400.00
Flags: fpu de tsc msr pae mce cx8 apic mca cmov pat clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid tsc_known_fr
eq pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c hypervisor lahf_lm cmp_legacy abm sse4a misalignsse 3dnowprefetch bpext cpb ibpb vmmcall fsgsbase bmi1
avx2 bmi2 adx clflushopt sha_ni xsaveopt xsavec xgetbv1 clzero xsaveerptr arat
Virtualization features:
Hypervisor vendor: Xen
Virtualization type: none
NUMA:
NUMA node(s): 1
NUMA node0 CPU(s): 0-3
Vulnerabilities:
Gather data sampling: Not affected
Itlb multihit: Not affected
L1tf: Not affected
Mds: Not affected
Meltdown: Not affected
Mmio stale data: Not affected
Reg file data sampling: Not affected
Retbleed: Vulnerable
Spec rstack overflow: Not affected
Spec store bypass: Vulnerable
Spectre v1: Vulnerable: __user pointer sanitization and usercopy barriers only; no swapgs barriers
Spectre v2: Vulnerable; IBPB: disabled; STIBP: disabled; PBRSB-eIBRS: Not affected; BHI: Not affected
Srbds: Not affected
Tsx async abort: Not affected
