Date: Fri, 13 Feb 2026 01:23:31 +0000 From: bugzilla-noreply@freebsd.org To: virtualization@FreeBSD.org Subject: [Bug 291768] bhyve won't boot anything on 15.0 - AMD EPYC 9124 Message-ID: <bug-291768-27103-onMR38eT5i@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-291768-27103@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=291768 --- Comment #23 from Tom <freebsd@fizz.buzz> --- One oddity I've noticed that might be related: A bunch of CPU feature flags are missing inside the guest including LA57. I've reproduced this with both a FreeBSD guest and a Linux guest. The flags that are present on the FreeBSD host but not the FreeBSD guest: INVPCID,PQM,PQE,ADX,AVX512IFMA,CLFLUSHOPT,CLWB,AVX512VBMI,UMIP,PKU,OSPKE,AVX512VBMI2,GFNI,AVX512VNNI,AVX512BITALG,AVX512VPOPCNTDQ,LA57,RDPID I compiled a test C program that uses AVX512IFMA instructions, and ran it inside the guest virtual machine. It ran successfully, proving the instructions work. It's just the flags are missing. I stumbled upon this because it breaks compiling some Qt software under Linux with -march=znver4 despite the CPU being a Zen 4 CPU. FreeBSD Host: ``` $ cat /var/run/dmesg.boot| grep -i "structured extended" Structured Extended Features=0xf1bf97a9<FSGSBASE,BMI1,AVX2,SMEP,BMI2,ERMS,INVPCID,PQM,PQE,AVX512F,AVX512DQ,RDSEED,ADX,SMAP,AVX512IFMA,CLFLUSHOPT,CLWB,AVX512CD,SHA,AVX512BW,AVX512VL> Structured Extended Features2=0x415fde<AVX512VBMI,UMIP,PKU,OSPKE,AVX512VBMI2,GFNI,VAES,VPCLMULQDQ,AVX512VNNI,AVX512BITALG,AVX512VPOPCNTDQ,LA57,RDPID> ``` FreeBSD Guest: ``` $ cat /var/run/dmesg.boot| grep -i "structured extended" Structured Extended Features=0xf01703a9<FSGSBASE,BMI1,AVX2,SMEP,BMI2,ERMS,AVX512F,AVX512DQ,RDSEED,SMAP,AVX512CD,SHA,AVX512BW,AVX512VL> Structured Extended Features2=0x600<VAES,VPCLMULQDQ> ``` -- You are receiving this mail because: You are the assignee for the bug.home | help
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