Date: Thu, 31 Jul 2025 16:28:28 +0100 From: Lexi Winter <ivy@freebsd.org> To: virtualization@freebsd.org Subject: how do i make a bhyve guest pick up the bhyve CPU topology? Message-ID: <aIuLnFbIqDZwqosm@freefall.freebsd.org>
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[-- Attachment #1 --] hello, i have a VM host with a CPU: CPU: Intel(R) Xeon(R) E E-2468 (2611.20-MHz K8-class CPU) HTT is disabled in the BIOS, so this shows up on the host as 1 socket x 8 cores: FreeBSD/SMP: Multiprocessor System Detected: 8 CPUs FreeBSD/SMP: 1 package(s) x 8 core(s) now i start a bhyve VM with '-c 2', but the VM does not pick up the expected topology (2 sockets x 1 core x 1 thread), instead it decides to enable HTT: FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs FreeBSD/SMP: 1 package(s) x 1 core(s) x 2 hardware threads if i force bhyve to set a particular topology, e.g. with '-c 2,sockets=2,cores=1,threads=1' then the guest still does not pick up the correct topology, but it does log some exciting new messages: WARNING: L1 data cache covers fewer APIC IDs than a core (0 < 1) WARNING: L2 data cache covers fewer APIC IDs than a core (0 < 1) WARNING: L3 data cache covers fewer APIC IDs than a core (0 < 1) FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs FreeBSD/SMP: 1 package(s) x 1 core(s) x 2 hardware threads this is using main ~29af6d2e2ec9fe8df7cf1e1a0bf3597028831b18 on amd64. does anyone have an idea what's going on here or how i can fix it? [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQSyjTg96lp3RifySyn1nT63mIK/YAUCaIuLmAAKCRD1nT63mIK/ YIn1AQCcBNtV2BkbXnk5RqJ2pBXKxZD7eu9uPRrUgds3eCLQggEA+6vF6VDZWpbR U5YaC0IX9kid+8RO/leECdCmfeZIwAk= =1z0H -----END PGP SIGNATURE-----
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