Changes to allow the GENERIC+bhye kernel built from this branch to

run as a 1/2 CPU guest on an 8.1 bhyve host.

bhyve/inout.c
      inout.h
      fbsdrun.c
 - Rather than exiting on accesses to unhandled i/o ports, emulate
   hardware by returning -1 on reads and ignoring writes to unhandled
   ports. Support the previous mode by allowing a 'strict' parameter
   to be set from the command line.
   The 8.1 guest kernel was vastly cut down from GENERIC and had no
   ISA devices. Booting GENERIC exposes a massive amount of random
   touching of i/o ports (hello syscons/vga/atkbdc).

bhyve/consport.c
dev/bvm/bvm_console.c
 - implement a simplistic signature for the bvm console by returning
   'bv' for an inw on the port. Also, set the priority of the console
   to CN_REMOTE if the signature was returned. This works better in
   an environment where multiple consoles are in the kernel (hello syscons)

bhyve/rtc.c
 - return 0 for the access to RTC_EQUIPMENT (yes, you syscons)

amd64/vmm/x86.c
          x86.h
 - hide a bunch more CPUID leaf 1 bits from the guest to prevent
   cpufreq drivers from probing.
   The next step will be to move CPUID handling completely into
   user-space. This will allow the full spectrum of changes from
   presenting a lowest-common-denominator CPU type/feature set, to
   exposing (almost) everything that the host can support.

Reviewed by:	neel
Obtained from:	NetApp

3 files changed, 30 insertions, 8 deletions

diff --git a/sys/amd64/vmm/x86.c b/sys/amd64/vmm/x86.c
index 45c4c53..f6b38e0 100644
--- a/sys/amd64/vmm/x86.c
+++ b/sys/amd64/vmm/x86.c
@@ -75,13 +75,19 @@ x86_emulate_cpuid(uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
 			regs[1] |= (0 << CPUID_0000_0001_APICID_SHIFT);
 
 			/*
-			 * Don't expose VMX capability.
+			 * Don't expose VMX, SpeedStep or TME capability.
 			 * Advertise x2APIC capability.
 			 */
-			regs[2] &= ~CPUID_0000_0001_FEAT0_VMX;
+			regs[2] &= ~(CPUID_0000_0001_FEAT0_VMX | CPUID2_EST |
+				     CPUID2_TM2);
 			regs[2] |= CPUID2_X2APIC;
 
 			/*
+			 * Hide thermal monitoring
+			 */
+			regs[3] &= ~(CPUID_ACPI | CPUID_TM);
+			
+			/*
 			 * Machine check handling is done in the host.
 			 * Hide MTRR capability.
 			 */
@@ -89,6 +95,17 @@ x86_emulate_cpuid(uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
 
 			break;
 
+		case CPUID_0000_0006:
+			/*
+			 * Handle the access, but report 0 for
+			 * all options
+			 */
+			regs[0] = 0;
+			regs[1] = 0;
+			regs[2] = 0;
+			regs[3] = 0;
+			break;
+
 		case CPUID_0000_000B:
 			/*
 			 * XXXSMP fixme
diff --git a/sys/amd64/vmm/x86.h b/sys/amd64/vmm/x86.h
index bc4f8a4..b437d61 100644
--- a/sys/amd64/vmm/x86.h
+++ b/sys/amd64/vmm/x86.h
@@ -34,6 +34,7 @@
 #define CPUID_0000_0002 (0x2)
 #define CPUID_0000_0003 (0x3)
 #define CPUID_0000_0004 (0x4)
+#define CPUID_0000_0006 (0x6)
 #define	CPUID_0000_000A	(0xA)
 #define	CPUID_0000_000B	(0xB)
 #define CPUID_8000_0000	(0x80000000)
diff --git a/sys/dev/bvm/bvm_console.c b/sys/dev/bvm/bvm_console.c
index ac12b6f..392346e 100644
--- a/sys/dev/bvm/bvm_console.c
+++ b/sys/dev/bvm/bvm_console.c
@@ -70,6 +70,8 @@ static int			alt_break_state;
 #define	BVM_CONS_PORT	0x220
 static int bvm_cons_port = BVM_CONS_PORT;
 
+#define BVM_CONS_SIG	('b' << 8 | 'v')
+
 static void	bvm_timeout(void *);
 
 static cn_probe_t	bvm_cnprobe;
@@ -171,14 +173,16 @@ bvm_cnprobe(struct consdev *cp)
 	int disabled, port;
 
 	disabled = 0;
+	cp->cn_pri = CN_DEAD;
+
 	resource_int_value("bvmconsole", 0, "disabled", &disabled);
-	if (disabled)
-		cp->cn_pri = CN_DEAD;
-	else
-		cp->cn_pri = CN_NORMAL;
+	if (!disabled) {
+		if (resource_int_value("bvmconsole", 0, "port", &port) == 0)
+			bvm_cons_port = port;
 
-	if (resource_int_value("bvmconsole", 0, "port", &port) == 0)
-		bvm_cons_port = port;
+		if (inw(bvm_cons_port) == BVM_CONS_SIG)
+			cp->cn_pri = CN_REMOTE;
+	}
 }
 
 static void