vmm: Emulate the byte forms of OR and AND with an immediate

[wanpengqian_gmail.com]

Summary

Opcode 0x80 (group 1: r/m8, imm8) is in the decode table and
emulate_cmp() handles 80 /7, but emulate_or() and emulate_and() only
accept 0x81 and 0x83. An "or byte ptr [mem], imm8" or "and byte ptr
[mem], imm8" on emulated memory therefore fails with EINVAL and bhyve
stops the guest with "Failed to emulate instruction sequence
[ 80 ... ]". Seen with macOS: VoodooHDA starts the HDA controller's
CORB with "or byte [rax+0x4c], 2" (CORBCTL |= CORBRUN), and the guest
died at the first sound.

Accept 0x80 in both, with a one byte operand as emulate_cmp() does.
The file is shared with bhyve(8), so the fix covers the in-kernel
devices (HPET, local APIC without APICv, I/O APIC) and the user space
device models alike.

Signed-off-by: Wanpeng Qian <[e-mail]>
Sponsored by: keelos.dev

Test Plan

Nested FreeBSD main on QEMU/KVM as the bhyve host, guest FreeBSD 16.0-CURRENT (2 vCPUs, bhyveload). A small program in the guest maps a device register through /dev/mem and executes "orb $4, (mem)" (80 /1) and "andb $-5, (mem)" (80 /4), reading the byte back after each.

In-kernel device model (HPET at 0xfed00000): without the change bhyve exits with "vm_run error -1, errno 22" (vmm_emulate_instruction() returned EINVAL) the moment the guest executes the orb; with the change the guest keeps running. The HPET model only takes 4 and 8 byte accesses, so the read-back stays 0 there; the value check was done on a user space model.

User space device model (fbuf, BAR0 + 0x20, a reserved register byte the model stores as written): without the change bhyve aborts with "Failed to emulate instruction sequence [ 800c03040fb61403802403fb0fb60c ] at 0x2017fd"; with the change the byte reads 0, then 4 after the orb, then 0 after the andb, three runs in a row, and bhyve keeps running.

The runs used the same tree with and without the one commit; sys/modules/vmm and usr.sbin/bhyve build with -Werror without warnings, with and without WITH_BHYVE_SNAPSHOT.