Author: neel
Date: Tue Apr 29 18:42:56 2014
New Revision: 265101
URL: http://svnweb.freebsd.org/changeset/base/265101
Log:
Some Linux guests will implement a 'halt' by disabling the APIC and executing
the 'HLT' instruction. This condition was detected by 'vm_handle_hlt()' and
converted into the SPINDOWN_CPU exitcode . The bhyve(8) process would exit
the vcpu thread in response to a SPINDOWN_CPU and when the last vcpu was
spun down it would reset the virtual machine via vm_suspend(VM_SUSPEND_RESET).
This functionality was broken in r263780 in a way that made it impossible
to kill the bhyve(8) process because it would loop forever in
vm_handle_suspend().
Unbreak this by removing the code to spindown vcpus. Thus a 'halt' from
a Linux guest will appear to be hung but this is consistent with the
behavior on bare metal. The guest can be rebooted by using the bhyvectl
options '--force-reset' or '--force-poweroff'.
Reviewed by: grehan@
Modified:
head/sys/amd64/include/vmm.h
head/sys/amd64/vmm/vmm.c
head/usr.sbin/bhyve/bhyverun.c
Modified: head/sys/amd64/include/vmm.h
==============================================================================
--- head/sys/amd64/include/vmm.h Tue Apr 29 18:42:37 2014
(r265100)
+++ head/sys/amd64/include/vmm.h Tue Apr 29 18:42:56 2014
(r265101)
@@ -325,7 +325,7 @@ enum vm_exitcode {
VM_EXITCODE_PAGING,
VM_EXITCODE_INST_EMUL,
VM_EXITCODE_SPINUP_AP,
- VM_EXITCODE_SPINDOWN_CPU,
+ VM_EXITCODE_DEPRECATED1, /* used to be SPINDOWN_CPU */
VM_EXITCODE_RENDEZVOUS,
VM_EXITCODE_IOAPIC_EOI,
VM_EXITCODE_SUSPENDED,
Modified: head/sys/amd64/vmm/vmm.c
==============================================================================
--- head/sys/amd64/vmm/vmm.c Tue Apr 29 18:42:37 2014 (r265100)
+++ head/sys/amd64/vmm/vmm.c Tue Apr 29 18:42:56 2014 (r265101)
@@ -191,8 +191,6 @@ static int vmm_ipinum;
SYSCTL_INT(_hw_vmm, OID_AUTO, ipinum, CTLFLAG_RD, &vmm_ipinum, 0,
"IPI vector used for vcpu notifications");
-static void vm_deactivate_cpu(struct vm *vm, int vcpuid);
-
static void
vcpu_cleanup(struct vm *vm, int i)
{
@@ -1006,60 +1004,47 @@ vm_handle_rendezvous(struct vm *vm, int
static int
vm_handle_hlt(struct vm *vm, int vcpuid, bool intr_disabled, bool *retu)
{
- struct vm_exit *vmexit;
struct vcpu *vcpu;
- int t, timo, spindown;
+ const char *wmesg;
+ int t;
vcpu = &vm->vcpu[vcpuid];
- spindown = 0;
vcpu_lock(vcpu);
+ while (1) {
+ /*
+ * Do a final check for pending NMI or interrupts before
+ * really putting this thread to sleep. Also check for
+ * software events that would cause this vcpu to wakeup.
+ *
+ * These interrupts/events could have happened after the
+ * vcpu returned from VMRUN() and before it acquired the
+ * vcpu lock above.
+ */
+ if (vm->rendezvous_func != NULL || vm->suspend)
+ break;
+ if (vm_nmi_pending(vm, vcpuid))
+ break;
+ if (!intr_disabled) {
+ if (vm_extint_pending(vm, vcpuid) ||
+ vlapic_pending_intr(vcpu->vlapic, NULL)) {
+ break;
+ }
+ }
+
+ if (vlapic_enabled(vcpu->vlapic))
+ wmesg = "vmidle";
+ else
+ wmesg = "vmhalt";
- /*
- * Do a final check for pending NMI or interrupts before
- * really putting this thread to sleep.
- *
- * These interrupts could have happened any time after we
- * returned from VMRUN() and before we grabbed the vcpu lock.
- */
- if (vm->rendezvous_func == NULL &&
- !vm_nmi_pending(vm, vcpuid) &&
- (intr_disabled || !vlapic_pending_intr(vcpu->vlapic, NULL))) {
t = ticks;
vcpu_require_state_locked(vcpu, VCPU_SLEEPING);
- if (vlapic_enabled(vcpu->vlapic)) {
- /*
- * XXX msleep_spin() is not interruptible so use the
- * 'timo' to put an upper bound on the sleep time.
- */
- timo = hz;
- msleep_spin(vcpu, &vcpu->mtx, "vmidle", timo);
- } else {
- /*
- * Spindown the vcpu if the APIC is disabled and it
- * had entered the halted state, but never spin
- * down the BSP.
- */
- if (vcpuid != 0)
- spindown = 1;
- }
+ msleep_spin(vcpu, &vcpu->mtx, wmesg, 0);
vcpu_require_state_locked(vcpu, VCPU_FROZEN);
vmm_stat_incr(vm, vcpuid, VCPU_IDLE_TICKS, ticks - t);
}
vcpu_unlock(vcpu);
- /*
- * Since 'vm_deactivate_cpu()' grabs a sleep mutex we must call it
- * outside the confines of the vcpu spinlock.
- */
- if (spindown) {
- *retu = true;
- vmexit = vm_exitinfo(vm, vcpuid);
- vmexit->exitcode = VM_EXITCODE_SPINDOWN_CPU;
- vm_deactivate_cpu(vm, vcpuid);
- VCPU_CTR0(vm, vcpuid, "spinning down cpu");
- }
-
return (0);
}
@@ -1673,30 +1658,6 @@ vm_activate_cpu(struct vm *vm, int vcpui
CPU_SET_ATOMIC(vcpuid, &vm->active_cpus);
}
-static void
-vm_deactivate_cpu(struct vm *vm, int vcpuid)
-{
-
- KASSERT(vcpuid >= 0 && vcpuid < VM_MAXCPU,
- ("vm_deactivate_cpu: invalid vcpuid %d", vcpuid));
- KASSERT(CPU_ISSET(vcpuid, &vm->active_cpus),
- ("vm_deactivate_cpu: vcpuid %d is not active", vcpuid));
-
- VCPU_CTR0(vm, vcpuid, "deactivated");
- CPU_CLR_ATOMIC(vcpuid, &vm->active_cpus);
-
- /*
- * If a vcpu rendezvous is in progress then it could be blocked
- * on 'vcpuid' - unblock it before disappearing forever.
- */
- mtx_lock(&vm->rendezvous_mtx);
- if (vm->rendezvous_func != NULL) {
- VCPU_CTR0(vm, vcpuid, "unblock rendezvous after deactivation");
- wakeup(&vm->rendezvous_func);
- }
- mtx_unlock(&vm->rendezvous_mtx);
-}
-
cpuset_t
vm_active_cpus(struct vm *vm)
{
Modified: head/usr.sbin/bhyve/bhyverun.c
==============================================================================
--- head/usr.sbin/bhyve/bhyverun.c Tue Apr 29 18:42:37 2014
(r265100)
+++ head/usr.sbin/bhyve/bhyverun.c Tue Apr 29 18:42:56 2014
(r265101)
@@ -114,6 +114,7 @@ struct bhyvestats {
uint64_t cpu_switch_rotate;
uint64_t cpu_switch_direct;
int io_reset;
+ int io_poweroff;
} stats;
struct mt_vmm_info {
@@ -237,13 +238,6 @@ fbsdrun_deletecpu(struct vmctx *ctx, int
}
static int
-vmexit_catch_reset(void)
-{
- stats.io_reset++;
- return (VMEXIT_RESET);
-}
-
-static int
vmexit_catch_inout(void)
{
return (VMEXIT_ABORT);
@@ -293,8 +287,10 @@ vmexit_inout(struct vmctx *ctx, struct v
case INOUT_OK:
return (VMEXIT_CONTINUE);
case INOUT_RESET:
+ stats.io_reset++;
return (VMEXIT_RESET);
case INOUT_POWEROFF:
+ stats.io_poweroff++;
return (VMEXIT_POWEROFF);
default:
fprintf(stderr, "Unhandled %s%c 0x%04x\n",
@@ -365,17 +361,6 @@ vmexit_spinup_ap(struct vmctx *ctx, stru
}
static int
-vmexit_spindown_cpu(struct vmctx *ctx, struct vm_exit *vme, int *pvcpu)
-{
- int lastcpu;
-
- lastcpu = fbsdrun_deletecpu(ctx, *pvcpu);
- if (!lastcpu)
- pthread_exit(NULL);
- return (vmexit_catch_reset());
-}
-
-static int
vmexit_vmx(struct vmctx *ctx, struct vm_exit *vmexit, int *pvcpu)
{
@@ -501,7 +486,6 @@ static vmexit_handler_t handler[VM_EXITC
[VM_EXITCODE_MTRAP] = vmexit_mtrap,
[VM_EXITCODE_INST_EMUL] = vmexit_inst_emul,
[VM_EXITCODE_SPINUP_AP] = vmexit_spinup_ap,
- [VM_EXITCODE_SPINDOWN_CPU] = vmexit_spindown_cpu,
[VM_EXITCODE_SUSPENDED] = vmexit_suspend
};
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