MFC 262139,262140,262236,262281,262532:

Various x2APIC fixes and enhancements:
- Use spinlocks for the vioapic.
- Handle the SELF_IPI MSR.
- Simplify the APIC mode switching between MMIO and x2APIC.  The guest is
  no longer allowed to switch modes at runtime.  Instead, the desired mode
  is set when the virtual machine is created.
- Disallow MMIO access in x2APIC mode and MSR access in xAPIC mode.
- Add support for x2APIC virtualization assist in Intel VT-x.

2 files changed, 19 insertions, 17 deletions

diff --git a/usr.sbin/bhyve/bhyve.8 b/usr.sbin/bhyve/bhyve.8
index 7766f18..74a840d 100644
--- a/usr.sbin/bhyve/bhyve.8
+++ b/usr.sbin/bhyve/bhyve.8
@@ -32,7 +32,7 @@
 .Nd "run a guest operating system inside a virtual machine"
 .Sh SYNOPSIS
 .Nm
-.Op Fl aehwAHPW
+.Op Fl aehwxAHPW
 .Op Fl c Ar numcpus
 .Op Fl g Ar gdbport
 .Op Fl p Ar pinnedcpu
@@ -58,7 +58,9 @@ exit is detected.
 .Sh OPTIONS
 .Bl -tag -width 10n
 .It Fl a
-Disallow use of the local APIC in X2APIC mode.
+The guest's local APIC is configured in xAPIC mode.
+The xAPIC mode is the default setting so this option is redundant. It will be
+deprecated in a future version.
 .It Fl A
 Generate ACPI tables.
 Required for
@@ -223,6 +225,8 @@ to exit when a guest issues an access to an I/O port that is not emulated.
 This is intended for debug purposes.
 .It Fl w
 Ignore accesses to unimplemented Model Specific Registers (MSRs). This is intended for debug purposes.
+.It Fl x
+The guest's local APIC is configured in x2APIC mode.
 .It Fl h
 Print help message and exit.
 .It Ar vmname
diff --git a/usr.sbin/bhyve/bhyverun.c b/usr.sbin/bhyve/bhyverun.c
index b6662ca..ea0e60a 100644
--- a/usr.sbin/bhyve/bhyverun.c
+++ b/usr.sbin/bhyve/bhyverun.c
@@ -84,8 +84,9 @@ char *vmname;
 int guest_ncpus;
 
 static int pincpu = -1;
-static int guest_vmexit_on_hlt, guest_vmexit_on_pause, disable_x2apic;
+static int guest_vmexit_on_hlt, guest_vmexit_on_pause;
 static int virtio_msix = 1;
+static int x2apic_mode = 0;	/* default is xAPIC */
 
 static int strictio;
 static int strictmsr = 1;
@@ -126,7 +127,7 @@ usage(int code)
         fprintf(stderr,
                 "Usage: %s [-aehwAHIPW] [-g <gdb port>] [-s <pci>]\n"
 		"       %*s [-c vcpus] [-p pincpu] [-m mem] [-l <lpc>] <vm>\n"
-		"       -a: local apic is in XAPIC mode (default is X2APIC)\n"
+		"       -a: local apic is in xAPIC mode (deprecated)\n"
 		"       -A: create an ACPI table\n"
 		"       -g: gdb port\n"
 		"       -c: # cpus (default 1)\n"
@@ -139,7 +140,8 @@ usage(int code)
 		"       -s: <slot,driver,configinfo> PCI slot config\n"
 		"       -l: LPC device configuration\n"
 		"       -m: memory size in MB\n"
-		"       -w: ignore unimplemented MSRs\n",
+		"       -w: ignore unimplemented MSRs\n"
+		"       -x: local apic is in x2APIC mode\n",
 		progname, (int)strlen(progname), "");
 
 	exit(code);
@@ -153,13 +155,6 @@ paddr_guest2host(struct vmctx *ctx, uintptr_t gaddr, size_t len)
 }
 
 int
-fbsdrun_disable_x2apic(void)
-{
-
-	return (disable_x2apic);
-}
-
-int
 fbsdrun_vmexit_on_pause(void)
 {
 
@@ -576,10 +571,10 @@ fbsdrun_set_capabilities(struct vmctx *ctx, int cpu)
 			handler[VM_EXITCODE_PAUSE] = vmexit_pause;
         }
 
-	if (fbsdrun_disable_x2apic())
-		err = vm_set_x2apic_state(ctx, cpu, X2APIC_DISABLED);
-	else
+	if (x2apic_mode)
 		err = vm_set_x2apic_state(ctx, cpu, X2APIC_ENABLED);
+	else
+		err = vm_set_x2apic_state(ctx, cpu, X2APIC_DISABLED);
 
 	if (err) {
 		fprintf(stderr, "Unable to set x2apic state (%d)\n", err);
@@ -604,10 +599,10 @@ main(int argc, char *argv[])
 	guest_ncpus = 1;
 	memsize = 256 * MB;
 
-	while ((c = getopt(argc, argv, "abehwAHIPWp:g:c:s:m:l:")) != -1) {
+	while ((c = getopt(argc, argv, "abehwxAHIPWp:g:c:s:m:l:")) != -1) {
 		switch (c) {
 		case 'a':
-			disable_x2apic = 1;
+			x2apic_mode = 0;
 			break;
 		case 'A':
 			acpi = 1;
@@ -664,6 +659,9 @@ main(int argc, char *argv[])
 		case 'W':
 			virtio_msix = 0;
 			break;
+		case 'x':
+			x2apic_mode = 1;
+			break;
 		case 'h':
 			usage(0);			
 		default: