diff options
-rw-r--r-- | usr.sbin/bhyve/consport.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/usr.sbin/bhyve/consport.c b/usr.sbin/bhyve/consport.c index b9eb4ce..4074e95 100644 --- a/usr.sbin/bhyve/consport.c +++ b/usr.sbin/bhyve/consport.c @@ -110,6 +110,15 @@ console_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes, return (0); } + /* + * Guests might probe this port to look for old ISA devices + * using single-byte reads. Return 0xff for those. + */ + if (bytes == 1 && in) { + *eax = 0xff; + return (0); + } + if (bytes != 4) return (-1); |