| 1 | // SPDX-License-Identifier: GPL-2.0 |
|---|---|
| 2 | /* |
| 3 | * FreeBSD Bhyve guest enlightenments |
| 4 | * |
| 5 | * Copyright © 2025 Amazon.com, Inc. or its affiliates. |
| 6 | * |
| 7 | * Author: David Woodhouse <dwmw2@infradead.org> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/init.h> |
| 11 | #include <linux/export.h> |
| 12 | #include <asm/processor.h> |
| 13 | #include <asm/hypervisor.h> |
| 14 | |
| 15 | static uint32_t bhyve_cpuid_base; |
| 16 | static uint32_t bhyve_cpuid_max; |
| 17 | |
| 18 | #define BHYVE_SIGNATURE "bhyve bhyve " |
| 19 | |
| 20 | #define CPUID_BHYVE_FEATURES 0x40000001 |
| 21 | |
| 22 | /* Features advertised in CPUID_BHYVE_FEATURES %eax */ |
| 23 | |
| 24 | /* MSI Extended Dest ID */ |
| 25 | #define CPUID_BHYVE_FEAT_EXT_DEST_ID (1UL << 0) |
| 26 | |
| 27 | static uint32_t __init bhyve_detect(void) |
| 28 | { |
| 29 | if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR)) |
| 30 | return 0; |
| 31 | |
| 32 | bhyve_cpuid_base = cpuid_base_hypervisor(BHYVE_SIGNATURE, leaves: 0); |
| 33 | if (!bhyve_cpuid_base) |
| 34 | return 0; |
| 35 | |
| 36 | bhyve_cpuid_max = cpuid_eax(op: bhyve_cpuid_base); |
| 37 | return bhyve_cpuid_max; |
| 38 | } |
| 39 | |
| 40 | static uint32_t bhyve_features(void) |
| 41 | { |
| 42 | unsigned int cpuid_leaf = bhyve_cpuid_base | CPUID_BHYVE_FEATURES; |
| 43 | |
| 44 | if (bhyve_cpuid_max < cpuid_leaf) |
| 45 | return 0; |
| 46 | |
| 47 | return cpuid_eax(op: cpuid_leaf); |
| 48 | } |
| 49 | |
| 50 | static bool __init bhyve_ext_dest_id(void) |
| 51 | { |
| 52 | return !!(bhyve_features() & CPUID_BHYVE_FEAT_EXT_DEST_ID); |
| 53 | } |
| 54 | |
| 55 | static bool __init bhyve_x2apic_available(void) |
| 56 | { |
| 57 | return true; |
| 58 | } |
| 59 | |
| 60 | const struct hypervisor_x86 x86_hyper_bhyve __refconst = { |
| 61 | .name = "Bhyve", |
| 62 | .detect = bhyve_detect, |
| 63 | .init.init_platform = x86_init_noop, |
| 64 | .init.x2apic_available = bhyve_x2apic_available, |
| 65 | .init.msi_ext_dest_id = bhyve_ext_dest_id, |
| 66 | }; |
| 67 |