diff options
| author | David Woodhouse <dwmw@amazon.co.uk> | 2025-08-11 10:44:05 +0000 |
|---|---|---|
| committer | Colin Percival <cperciva@FreeBSD.org> | 2025-08-13 20:31:15 +0000 |
| commit | 313a68ea20b48629f655cf38987f4a6ff822f1ab (patch) | |
| tree | 0d3adadeb2d1c235ccbffa7b0f58973ad652e24c | |
| parent | e990e460d50c628dfa681c5693bd8ece87b001ad (diff) | |
bhyve: Add CPUID_BHYVE_FEATURES leaf
This allows the hypervisor to advertise features to the guest. The first
such feature is CPUID_BHYVE_EXT_DEST_ID which advertises that 15 bits
of target APIC ID are available in MSI (and I/O APIC) interrupts, as
documented in http://david.woodhou.se/ExtDestId.pdf
This defines the guest ABI. The actual implementation will come in a
subsequent commit.
Reviewed by: kib
Pull Request: https://github.com/freebsd/freebsd-src/pull/1797
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
| -rw-r--r-- | sys/amd64/vmm/x86.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/sys/amd64/vmm/x86.c b/sys/amd64/vmm/x86.c index 366f1da9f850..9c2fdac11a81 100644 --- a/sys/amd64/vmm/x86.c +++ b/sys/amd64/vmm/x86.c @@ -48,7 +48,12 @@ SYSCTL_DECL(_hw_vmm); static SYSCTL_NODE(_hw_vmm, OID_AUTO, topology, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, NULL); -#define CPUID_VM_HIGH 0x40000000 +#define CPUID_VM_SIGNATURE 0x40000000 +#define CPUID_BHYVE_FEATURES 0x40000001 +#define CPUID_VM_HIGH CPUID_BHYVE_FEATURES + +/* Features advertised in CPUID_BHYVE_FEATURES %eax */ +#define CPUID_BHYVE_FEAT_EXT_DEST_ID (1UL << 0) /* MSI Extended Dest ID */ static const char bhyve_id[12] = "bhyve bhyve "; @@ -100,7 +105,7 @@ x86_emulate_cpuid(struct vcpu *vcpu, uint64_t *rax, uint64_t *rbx, if (cpu_exthigh != 0 && func >= 0x80000000) { if (func > cpu_exthigh) func = cpu_exthigh; - } else if (func >= 0x40000000) { + } else if (func >= CPUID_VM_SIGNATURE) { if (func > CPUID_VM_HIGH) func = CPUID_VM_HIGH; } else if (func > cpu_high) { @@ -601,13 +606,20 @@ x86_emulate_cpuid(struct vcpu *vcpu, uint64_t *rax, uint64_t *rbx, regs[3] = 0; break; - case 0x40000000: + case CPUID_VM_SIGNATURE: regs[0] = CPUID_VM_HIGH; bcopy(bhyve_id, ®s[1], 4); bcopy(bhyve_id + 4, ®s[2], 4); bcopy(bhyve_id + 8, ®s[3], 4); break; + case CPUID_BHYVE_FEATURES: + regs[0] = 0; /* No features to advertise yet */ + regs[1] = 0; + regs[2] = 0; + regs[3] = 0; + break; + default: default_leaf: /* |