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Add an ioctl to suspend a virtual machine (VM_SUSPEND). The ioctl can be called

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from any context i.e., it is not required to be called from a vcpu thread. The
ioctl simply sets a state variable 'vm->suspend' to '1' and returns.

The vcpus inspect 'vm->suspend' in the run loop and if it is set to '1' the
vcpu breaks out of the loop with a reason of 'VM_EXITCODE_SUSPENDED'. The
suspend handler waits until all 'vm->active_cpus' have transitioned to
'vm->suspended_cpus' before returning to userspace.

Discussed with:	grehan
This commit is contained in:
neel 2014-03-26 23:34:27 +00:00
parent 0b79334339
commit 3e49998fdf
9 changed files with 159 additions and 10 deletions
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7
lib/libvmmapi/vmmapi.c
View File

@ -342,6 +342,13 @@ vm_run(struct vmctx *ctx, int vcpu, uint64_t rip, struct vm_exit *vmexit)
return (error);
}
int
vm_suspend(struct vmctx *ctx)
{
return (ioctl(ctx->fd, VM_SUSPEND, 0));
}
static int
vm_inject_exception_real(struct vmctx *ctx, int vcpu, int vector,
int error_code, int error_code_valid)

1
lib/libvmmapi/vmmapi.h
View File

@ -61,6 +61,7 @@ int vm_set_register(struct vmctx *ctx, int vcpu, int reg, uint64_t val);
int vm_get_register(struct vmctx *ctx, int vcpu, int reg, uint64_t *retval);
int vm_run(struct vmctx *ctx, int vcpu, uint64_t rip,
struct vm_exit *ret_vmexit);
int vm_suspend(struct vmctx *ctx);
int vm_apicid2vcpu(struct vmctx *ctx, int apicid);
int vm_inject_exception(struct vmctx *ctx, int vcpu, int vec);
int vm_inject_exception2(struct vmctx *ctx, int vcpu, int vec, int errcode);

12
sys/amd64/include/vmm.h
View File

@ -53,7 +53,8 @@ typedef int (*vmm_cleanup_func_t)(void);
typedef void (*vmm_resume_func_t)(void);
typedef void * (*vmi_init_func_t)(struct vm *vm, struct pmap *pmap);
typedef int (*vmi_run_func_t)(void *vmi, int vcpu, register_t rip,
struct pmap *pmap, void *rendezvous_cookie);
struct pmap *pmap, void *rendezvous_cookie,
void *suspend_cookie);
typedef void (*vmi_cleanup_func_t)(void *vmi);
typedef int (*vmi_get_register_t)(void *vmi, int vcpu, int num,
uint64_t *retval);
@ -114,6 +115,7 @@ int vm_get_seg_desc(struct vm *vm, int vcpu, int reg,
int vm_set_seg_desc(struct vm *vm, int vcpu, int reg,
struct seg_desc *desc);
int vm_run(struct vm *vm, struct vm_run *vmrun);
int vm_suspend(struct vm *vm);
int vm_inject_nmi(struct vm *vm, int vcpu);
int vm_nmi_pending(struct vm *vm, int vcpuid);
void vm_nmi_clear(struct vm *vm, int vcpuid);
@ -158,6 +160,13 @@ vcpu_rendezvous_pending(void *rendezvous_cookie)
return (*(uintptr_t *)rendezvous_cookie != 0);
}
static __inline int
vcpu_suspended(void *suspend_cookie)
{
return (*(int *)suspend_cookie);
}
/*
* Return 1 if device indicated by bus/slot/func is supposed to be a
* pci passthrough device.
@ -311,6 +320,7 @@ enum vm_exitcode {
VM_EXITCODE_SPINDOWN_CPU,
VM_EXITCODE_RENDEZVOUS,
VM_EXITCODE_IOAPIC_EOI,
VM_EXITCODE_SUSPENDED,
VM_EXITCODE_MAX
};

3
sys/amd64/include/vmm_dev.h
View File

@ -165,6 +165,7 @@ enum {
IOCNUM_RUN = 1,
IOCNUM_SET_CAPABILITY = 2,
IOCNUM_GET_CAPABILITY = 3,
IOCNUM_SUSPEND = 4,
/* memory apis */
IOCNUM_MAP_MEMORY = 10,
@ -212,6 +213,8 @@ enum {
#define VM_RUN \
_IOWR('v', IOCNUM_RUN, struct vm_run)
#define VM_SUSPEND \
_IO('v', IOCNUM_SUSPEND)
#define VM_MAP_MEMORY \
_IOWR('v', IOCNUM_MAP_MEMORY, struct vm_memory_segment)
#define VM_GET_MEMORY_SEG \

3
sys/amd64/vmm/amd/amdv.c
View File

@ -67,7 +67,8 @@ amdv_vminit(struct vm *vm, struct pmap *pmap)
}
static int
amdv_vmrun(void *arg, int vcpu, register_t rip, struct pmap *pmap, void *cookie)
amdv_vmrun(void *arg, int vcpu, register_t rip, struct pmap *pmap,
void *rptr, void *sptr)
{
printf("amdv_vmrun: not implemented\n");

22
sys/amd64/vmm/intel/vmx.c
View File

@ -2037,6 +2037,16 @@ vmx_exit_rendezvous(struct vmx *vmx, int vcpu, struct vm_exit *vmexit)
return (UNHANDLED);
}
static __inline int
vmx_exit_suspended(struct vmx *vmx, int vcpu, struct vm_exit *vmexit)
{
vmexit->rip = vmcs_guest_rip();
vmexit->inst_length = 0;
vmexit->exitcode = VM_EXITCODE_SUSPENDED;
return (UNHANDLED);
}
static __inline int
vmx_exit_inst_error(struct vmxctx *vmxctx, int rc, struct vm_exit *vmexit)
{
@ -2097,7 +2107,7 @@ vmx_exit_handle_nmi(struct vmx *vmx, int vcpuid, struct vm_exit *vmexit)
static int
vmx_run(void *arg, int vcpu, register_t startrip, pmap_t pmap,
void *rendezvous_cookie)
void *rendezvous_cookie, void *suspend_cookie)
{
int rc, handled, launched;
struct vmx *vmx;
@ -2154,9 +2164,9 @@ vmx_run(void *arg, int vcpu, register_t startrip, pmap_t pmap,
* pmap_invalidate_ept().
*/
disable_intr();
if (curthread->td_flags & (TDF_ASTPENDING | TDF_NEEDRESCHED)) {
if (vcpu_suspended(suspend_cookie)) {
enable_intr();
handled = vmx_exit_astpending(vmx, vcpu, vmexit);
handled = vmx_exit_suspended(vmx, vcpu, vmexit);
break;
}
@ -2166,6 +2176,12 @@ vmx_run(void *arg, int vcpu, register_t startrip, pmap_t pmap,
break;
}
if (curthread->td_flags & (TDF_ASTPENDING | TDF_NEEDRESCHED)) {
enable_intr();
handled = vmx_exit_astpending(vmx, vcpu, vmexit);
break;
}
vmx_inject_interrupts(vmx, vcpu, vlapic);
vmx_run_trace(vmx, vcpu);
rc = vmx_enter_guest(vmxctx, vmx, launched);

83
sys/amd64/vmm/vmm.c
View File

@ -139,6 +139,9 @@ struct vm {
cpuset_t rendezvous_done_cpus;
void *rendezvous_arg;
vm_rendezvous_func_t rendezvous_func;
int suspend;
volatile cpuset_t suspended_cpus;
};
static int vmm_initialized;
@ -149,8 +152,8 @@ static struct vmm_ops *ops;
#define VMM_RESUME() (ops != NULL ? (*ops->resume)() : 0)
#define VMINIT(vm, pmap) (ops != NULL ? (*ops->vminit)(vm, pmap): NULL)
#define VMRUN(vmi, vcpu, rip, pmap, rptr) \
(ops != NULL ? (*ops->vmrun)(vmi, vcpu, rip, pmap, rptr) : ENXIO)
#define VMRUN(vmi, vcpu, rip, pmap, rptr, sptr) \
(ops != NULL ? (*ops->vmrun)(vmi, vcpu, rip, pmap, rptr, sptr) : ENXIO)
#define VMCLEANUP(vmi) (ops != NULL ? (*ops->vmcleanup)(vmi) : NULL)
#define VMSPACE_ALLOC(min, max) \
(ops != NULL ? (*ops->vmspace_alloc)(min, max) : NULL)
@ -1019,7 +1022,8 @@ vm_handle_hlt(struct vm *vm, int vcpuid, bool intr_disabled, bool *retu)
* These interrupts could have happened any time after we
* returned from VMRUN() and before we grabbed the vcpu lock.
*/
if (!vm_nmi_pending(vm, vcpuid) &&
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);
@ -1152,6 +1156,71 @@ vm_handle_inst_emul(struct vm *vm, int vcpuid, bool *retu)
return (error);
}
static int
vm_handle_suspend(struct vm *vm, int vcpuid, bool *retu)
{
int i, done;
struct vcpu *vcpu;
done = 0;
vcpu = &vm->vcpu[vcpuid];
CPU_SET_ATOMIC(vcpuid, &vm->suspended_cpus);
/*
* Wait until all 'active_cpus' have suspended themselves.
*
* Since a VM may be suspended at any time including when one or
* more vcpus are doing a rendezvous we need to call the rendezvous
* handler while we are waiting to prevent a deadlock.
*/
vcpu_lock(vcpu);
while (1) {
if (CPU_CMP(&vm->suspended_cpus, &vm->active_cpus) == 0) {
VCPU_CTR0(vm, vcpuid, "All vcpus suspended");
break;
}
if (vm->rendezvous_func == NULL) {
VCPU_CTR0(vm, vcpuid, "Sleeping during suspend");
vcpu_require_state_locked(vcpu, VCPU_SLEEPING);
msleep_spin(vcpu, &vcpu->mtx, "vmsusp", hz);
vcpu_require_state_locked(vcpu, VCPU_FROZEN);
} else {
VCPU_CTR0(vm, vcpuid, "Rendezvous during suspend");
vcpu_unlock(vcpu);
vm_handle_rendezvous(vm, vcpuid);
vcpu_lock(vcpu);
}
}
vcpu_unlock(vcpu);
/*
* Wakeup the other sleeping vcpus and return to userspace.
*/
for (i = 0; i < VM_MAXCPU; i++) {
if (CPU_ISSET(i, &vm->suspended_cpus)) {
vcpu_notify_event(vm, i, false);
}
}
*retu = true;
return (0);
}
int
vm_suspend(struct vm *vm)
{
if (atomic_cmpset_int(&vm->suspend, 0, 1)) {
VM_CTR0(vm, "virtual machine suspended");
return (0);
} else {
VM_CTR0(vm, "virtual machine already suspended");
return (EALREADY);
}
}
int
vm_run(struct vm *vm, struct vm_run *vmrun)
{
@ -1162,12 +1231,15 @@ vm_run(struct vm *vm, struct vm_run *vmrun)
struct vm_exit *vme;
bool retu, intr_disabled;
pmap_t pmap;
void *rptr, *sptr;
vcpuid = vmrun->cpuid;
if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
return (EINVAL);
rptr = &vm->rendezvous_func;
sptr = &vm->suspend;
pmap = vmspace_pmap(vm->vmspace);
vcpu = &vm->vcpu[vcpuid];
vme = &vcpu->exitinfo;
@ -1187,7 +1259,7 @@ vm_run(struct vm *vm, struct vm_run *vmrun)
restore_guest_fpustate(vcpu);
vcpu_require_state(vm, vcpuid, VCPU_RUNNING);
error = VMRUN(vm->cookie, vcpuid, rip, pmap, &vm->rendezvous_func);
error = VMRUN(vm->cookie, vcpuid, rip, pmap, rptr, sptr);
vcpu_require_state(vm, vcpuid, VCPU_FROZEN);
save_guest_fpustate(vcpu);
@ -1200,6 +1272,9 @@ vm_run(struct vm *vm, struct vm_run *vmrun)
if (error == 0) {
retu = false;
switch (vme->exitcode) {
case VM_EXITCODE_SUSPENDED:
error = vm_handle_suspend(vm, vcpuid, &retu);
break;
case VM_EXITCODE_IOAPIC_EOI:
vioapic_process_eoi(vm, vcpuid,
vme->u.ioapic_eoi.vector);

3
sys/amd64/vmm/vmm_dev.c
View File

@ -239,6 +239,9 @@ vmmdev_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
vmrun = (struct vm_run *)data;
error = vm_run(sc->vm, vmrun);
break;
case VM_SUSPEND:
error = vm_suspend(sc->vm);
break;
case VM_STAT_DESC: {
statdesc = (struct vm_stat_desc *)data;
error = vmm_stat_desc_copy(statdesc->index,

35
usr.sbin/bhyve/bhyverun.c
View File

@ -463,6 +463,33 @@ vmexit_inst_emul(struct vmctx *ctx, struct vm_exit *vmexit, int *pvcpu)
return (VMEXIT_CONTINUE);
}
static pthread_mutex_t resetcpu_mtx = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t resetcpu_cond = PTHREAD_COND_INITIALIZER;
static int resetcpu = -1;
static int
vmexit_suspend(struct vmctx *ctx, struct vm_exit *vmexit, int *pvcpu)
{
assert(resetcpu != -1);
fbsdrun_deletecpu(ctx, *pvcpu);
if (*pvcpu != resetcpu) {
pthread_mutex_lock(&resetcpu_mtx);
pthread_cond_signal(&resetcpu_cond);
pthread_mutex_unlock(&resetcpu_mtx);
pthread_exit(NULL);
}
pthread_mutex_lock(&resetcpu_mtx);
while (!CPU_EMPTY(&cpumask)) {
pthread_cond_wait(&resetcpu_cond, &resetcpu_mtx);
}
pthread_mutex_unlock(&resetcpu_mtx);
exit(0);
}
static vmexit_handler_t handler[VM_EXITCODE_MAX] = {
[VM_EXITCODE_INOUT] = vmexit_inout,
[VM_EXITCODE_VMX] = vmexit_vmx,
@ -473,6 +500,7 @@ static vmexit_handler_t handler[VM_EXITCODE_MAX] = {
[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
};
static void
@ -514,7 +542,12 @@ vm_loop(struct vmctx *ctx, int vcpu, uint64_t rip)
rip = vmexit[vcpu].rip;
break;
case VMEXIT_RESET:
exit(0);
if (vm_suspend(ctx) == 0) {
assert(resetcpu == -1);
resetcpu = vcpu;
}
rip = vmexit[vcpu].rip + vmexit[vcpu].inst_length;
break;
default:
exit(1);
}