/*-
 * Copyright (c) 2011 NetApp, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/pcpu.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/systm.h>

#include <vm/vm.h>

#include <machine/vm.h>
#include <machine/pcb.h>
#include <x86/apicreg.h>

#include <machine/vmm.h>
#include "vmm_mem.h"
#include "vmm_util.h"
#include <machine/vmm_dev.h>
#include "vlapic.h"
#include "vmm_msr.h"
#include "vmm_ipi.h"
#include "vmm_stat.h"

#include "io/ppt.h"
#include "io/iommu.h"

struct vlapic;

struct vcpu {
	int		flags;
	int		pincpu;		/* host cpuid this vcpu is bound to */
	int		hostcpu;	/* host cpuid this vcpu last ran on */
	uint64_t	guest_msrs[VMM_MSR_NUM];
	struct vlapic	*vlapic;
	int		 vcpuid;
	struct savefpu	savefpu;	/* guest fpu state */
	void		*stats;
};
#define	VCPU_F_PINNED	0x0001
#define	VCPU_F_RUNNING	0x0002

#define	VCPU_PINCPU(vm, vcpuid)	\
    ((vm->vcpu[vcpuid].flags & VCPU_F_PINNED) ? vm->vcpu[vcpuid].pincpu : -1)

#define	VCPU_UNPIN(vm, vcpuid)	(vm->vcpu[vcpuid].flags &= ~VCPU_F_PINNED)

#define	VCPU_PIN(vm, vcpuid, host_cpuid)				\
do {									\
	vm->vcpu[vcpuid].flags |= VCPU_F_PINNED;			\
	vm->vcpu[vcpuid].pincpu = host_cpuid;				\
} while(0)

#define	VM_MAX_MEMORY_SEGMENTS	2

struct vm {
	void		*cookie;	/* processor-specific data */
	void		*iommu;		/* iommu-specific data */
	struct vcpu	vcpu[VM_MAXCPU];
	int		num_mem_segs;
	struct vm_memory_segment mem_segs[VM_MAX_MEMORY_SEGMENTS];
	char		name[VM_MAX_NAMELEN];

	/*
	 * Set of active vcpus.
	 * An active vcpu is one that has been started implicitly (BSP) or
	 * explicitly (AP) by sending it a startup ipi.
	 */
	cpuset_t	active_cpus;
};

static struct vmm_ops *ops;
#define	VMM_INIT()	(ops != NULL ? (*ops->init)() : 0)
#define	VMM_CLEANUP()	(ops != NULL ? (*ops->cleanup)() : 0)

#define	VMINIT(vm)	(ops != NULL ? (*ops->vminit)(vm): NULL)
#define	VMRUN(vmi, vcpu, rip, vmexit) \
	(ops != NULL ? (*ops->vmrun)(vmi, vcpu, rip, vmexit) : ENXIO)
#define	VMCLEANUP(vmi)	(ops != NULL ? (*ops->vmcleanup)(vmi) : NULL)
#define	VMMMAP(vmi, gpa, hpa, len, attr, prot, spm)	\
    (ops != NULL ? (*ops->vmmmap)(vmi, gpa, hpa, len, attr, prot, spm) : ENXIO)
#define	VMGETREG(vmi, vcpu, num, retval)		\
	(ops != NULL ? (*ops->vmgetreg)(vmi, vcpu, num, retval) : ENXIO)
#define	VMSETREG(vmi, vcpu, num, val)		\
	(ops != NULL ? (*ops->vmsetreg)(vmi, vcpu, num, val) : ENXIO)
#define	VMGETDESC(vmi, vcpu, num, desc)		\
	(ops != NULL ? (*ops->vmgetdesc)(vmi, vcpu, num, desc) : ENXIO)
#define	VMSETDESC(vmi, vcpu, num, desc)		\
	(ops != NULL ? (*ops->vmsetdesc)(vmi, vcpu, num, desc) : ENXIO)
#define	VMINJECT(vmi, vcpu, type, vec, ec, ecv)	\
	(ops != NULL ? (*ops->vminject)(vmi, vcpu, type, vec, ec, ecv) : ENXIO)
#define	VMNMI(vmi, vcpu)	\
	(ops != NULL ? (*ops->vmnmi)(vmi, vcpu) : ENXIO)
#define	VMGETCAP(vmi, vcpu, num, retval)	\
	(ops != NULL ? (*ops->vmgetcap)(vmi, vcpu, num, retval) : ENXIO)
#define	VMSETCAP(vmi, vcpu, num, val)		\
	(ops != NULL ? (*ops->vmsetcap)(vmi, vcpu, num, val) : ENXIO)

#define	fxrstor(addr)		__asm("fxrstor %0" : : "m" (*(addr)))
#define	fxsave(addr)		__asm __volatile("fxsave %0" : "=m" (*(addr)))
#define	fpu_start_emulating()	__asm("smsw %%ax; orb %0,%%al; lmsw %%ax" \
				      : : "n" (CR0_TS) : "ax")
#define	fpu_stop_emulating()	__asm("clts")

static MALLOC_DEFINE(M_VM, "vm", "vm");
CTASSERT(VMM_MSR_NUM <= 64);	/* msr_mask can keep track of up to 64 msrs */

/* statistics */
static VMM_STAT_DEFINE(VCPU_TOTAL_RUNTIME, "vcpu total runtime");

static void
vcpu_cleanup(struct vcpu *vcpu)
{
	vlapic_cleanup(vcpu->vlapic);
	vmm_stat_free(vcpu->stats);
}

static void
vcpu_init(struct vm *vm, uint32_t vcpu_id)
{
	struct vcpu *vcpu;
	
	vcpu = &vm->vcpu[vcpu_id];

	vcpu->hostcpu = -1;
	vcpu->vcpuid = vcpu_id;
	vcpu->vlapic = vlapic_init(vm, vcpu_id);
	fpugetregs(curthread);
	vcpu->savefpu = curthread->td_pcb->pcb_user_save;
	vcpu->stats = vmm_stat_alloc();
}

static int
vmm_init(void)
{
	int error;

	vmm_ipi_init();

	error = vmm_mem_init();
	if (error)
		return (error);
	
	if (vmm_is_intel())
		ops = &vmm_ops_intel;
	else if (vmm_is_amd())
		ops = &vmm_ops_amd;
	else
		return (ENXIO);

	vmm_msr_init();

	return (VMM_INIT());
}

static int
vmm_handler(module_t mod, int what, void *arg)
{
	int error;

	switch (what) {
	case MOD_LOAD:
		vmmdev_init();
		iommu_init();
		error = vmm_init();
		break;
	case MOD_UNLOAD:
		vmmdev_cleanup();
		iommu_cleanup();
		vmm_ipi_cleanup();
		error = VMM_CLEANUP();
		break;
	default:
		error = 0;
		break;
	}
	return (error);
}

static moduledata_t vmm_kmod = {
	"vmm",
	vmm_handler,
	NULL
};

/*
 * Execute the module load handler after the pci passthru driver has had
 * a chance to claim devices. We need this information at the time we do
 * iommu initialization.
 */
DECLARE_MODULE(vmm, vmm_kmod, SI_SUB_CONFIGURE + 1, SI_ORDER_ANY);
MODULE_VERSION(vmm, 1);

SYSCTL_NODE(_hw, OID_AUTO, vmm, CTLFLAG_RW, NULL, NULL);

struct vm *
vm_create(const char *name)
{
	int i;
	struct vm *vm;
	vm_paddr_t maxaddr;

	const int BSP = 0;

	if (name == NULL || strlen(name) >= VM_MAX_NAMELEN)
		return (NULL);

	vm = malloc(sizeof(struct vm), M_VM, M_WAITOK | M_ZERO);
	strcpy(vm->name, name);
	vm->cookie = VMINIT(vm);

	for (i = 0; i < VM_MAXCPU; i++) {
		vcpu_init(vm, i);
		guest_msrs_init(vm, i);
	}

	maxaddr = vmm_mem_maxaddr();
	vm->iommu = iommu_create_domain(maxaddr);
	vm_activate_cpu(vm, BSP);

	return (vm);
}

void
vm_destroy(struct vm *vm)
{
	int i;

	ppt_unassign_all(vm);

	for (i = 0; i < vm->num_mem_segs; i++)
		vmm_mem_free(vm->mem_segs[i].hpa, vm->mem_segs[i].len);

	for (i = 0; i < VM_MAXCPU; i++)
		vcpu_cleanup(&vm->vcpu[i]);

	iommu_destroy_domain(vm->iommu);

	VMCLEANUP(vm->cookie);

	free(vm, M_VM);
}

const char *
vm_name(struct vm *vm)
{
	return (vm->name);
}

int
vm_map_mmio(struct vm *vm, vm_paddr_t gpa, size_t len, vm_paddr_t hpa)
{
	const boolean_t spok = TRUE;	/* superpage mappings are ok */

	return (VMMMAP(vm->cookie, gpa, hpa, len, VM_MEMATTR_UNCACHEABLE,
		       VM_PROT_RW, spok));
}

int
vm_unmap_mmio(struct vm *vm, vm_paddr_t gpa, size_t len)
{
	const boolean_t spok = TRUE;	/* superpage mappings are ok */

	return (VMMMAP(vm->cookie, gpa, 0, len, VM_MEMATTR_UNCACHEABLE,
		       VM_PROT_NONE, spok));
}

int
vm_malloc(struct vm *vm, vm_paddr_t gpa, size_t len, vm_paddr_t *ret_hpa)
{
	int error;
	vm_paddr_t hpa;

	const boolean_t spok = TRUE;	/* superpage mappings are ok */
	
	/*
	 * find the hpa if already it was already vm_malloc'd.
	 */
	hpa = vm_gpa2hpa(vm, gpa, len);
	if (hpa != ((vm_paddr_t)-1))
		goto out;

	if (vm->num_mem_segs >= VM_MAX_MEMORY_SEGMENTS)
		return (E2BIG);

	hpa = vmm_mem_alloc(len);
	if (hpa == 0)
		return (ENOMEM);

	error = VMMMAP(vm->cookie, gpa, hpa, len, VM_MEMATTR_WRITE_BACK,
		       VM_PROT_ALL, spok);
	if (error) {
		vmm_mem_free(hpa, len);
		return (error);
	}

	iommu_create_mapping(vm->iommu, gpa, hpa, len);

	vm->mem_segs[vm->num_mem_segs].gpa = gpa;
	vm->mem_segs[vm->num_mem_segs].hpa = hpa;
	vm->mem_segs[vm->num_mem_segs].len = len;
	vm->num_mem_segs++;
out:
	*ret_hpa = hpa;
	return (0);
}

vm_paddr_t
vm_gpa2hpa(struct vm *vm, vm_paddr_t gpa, size_t len)
{
	int i;
	vm_paddr_t gpabase, gpalimit, hpabase;

	for (i = 0; i < vm->num_mem_segs; i++) {
		hpabase = vm->mem_segs[i].hpa;
		gpabase = vm->mem_segs[i].gpa;
		gpalimit = gpabase + vm->mem_segs[i].len;
		if (gpa >= gpabase && gpa + len <= gpalimit)
			return ((gpa - gpabase) + hpabase);
	}
	return ((vm_paddr_t)-1);
}

int
vm_gpabase2memseg(struct vm *vm, vm_paddr_t gpabase,
		  struct vm_memory_segment *seg)
{
	int i;

	for (i = 0; i < vm->num_mem_segs; i++) {
		if (gpabase == vm->mem_segs[i].gpa) {
			*seg = vm->mem_segs[i];
			return (0);
		}
	}
	return (-1);
}

int
vm_get_register(struct vm *vm, int vcpu, int reg, uint64_t *retval)
{

	if (vcpu < 0 || vcpu >= VM_MAXCPU)
		return (EINVAL);

	if (reg >= VM_REG_LAST)
		return (EINVAL);

	return (VMGETREG(vm->cookie, vcpu, reg, retval));
}

int
vm_set_register(struct vm *vm, int vcpu, int reg, uint64_t val)
{

	if (vcpu < 0 || vcpu >= VM_MAXCPU)
		return (EINVAL);

	if (reg >= VM_REG_LAST)
		return (EINVAL);

	return (VMSETREG(vm->cookie, vcpu, reg, val));
}

static boolean_t
is_descriptor_table(int reg)
{

	switch (reg) {
	case VM_REG_GUEST_IDTR:
	case VM_REG_GUEST_GDTR:
		return (TRUE);
	default:
		return (FALSE);
	}
}

static boolean_t
is_segment_register(int reg)
{
	
	switch (reg) {
	case VM_REG_GUEST_ES:
	case VM_REG_GUEST_CS:
	case VM_REG_GUEST_SS:
	case VM_REG_GUEST_DS:
	case VM_REG_GUEST_FS:
	case VM_REG_GUEST_GS:
	case VM_REG_GUEST_TR:
	case VM_REG_GUEST_LDTR:
		return (TRUE);
	default:
		return (FALSE);
	}
}

int
vm_get_seg_desc(struct vm *vm, int vcpu, int reg,
		struct seg_desc *desc)
{

	if (vcpu < 0 || vcpu >= VM_MAXCPU)
		return (EINVAL);

	if (!is_segment_register(reg) && !is_descriptor_table(reg))
		return (EINVAL);

	return (VMGETDESC(vm->cookie, vcpu, reg, desc));
}

int
vm_set_seg_desc(struct vm *vm, int vcpu, int reg,
		struct seg_desc *desc)
{
	if (vcpu < 0 || vcpu >= VM_MAXCPU)
		return (EINVAL);

	if (!is_segment_register(reg) && !is_descriptor_table(reg))
		return (EINVAL);

	return (VMSETDESC(vm->cookie, vcpu, reg, desc));
}

int
vm_get_pinning(struct vm *vm, int vcpuid, int *cpuid)
{

	if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
		return (EINVAL);

	*cpuid = VCPU_PINCPU(vm, vcpuid);

	return (0);
}

int
vm_set_pinning(struct vm *vm, int vcpuid, int host_cpuid)
{
	struct thread *td;

	if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
		return (EINVAL);

	td = curthread;		/* XXXSMP only safe when muxing vcpus */

	/* unpin */
	if (host_cpuid < 0) {
		VCPU_UNPIN(vm, vcpuid);
		thread_lock(td);
		sched_unbind(td);
		thread_unlock(td);
		return (0);
	}

	if (CPU_ABSENT(host_cpuid))
		return (EINVAL);

	/*
	 * XXX we should check that 'host_cpuid' has not already been pinned
	 * by another vm.
	 */
	thread_lock(td);
	sched_bind(td, host_cpuid);
	thread_unlock(td);
	VCPU_PIN(vm, vcpuid, host_cpuid);

	return (0);
}

static void
restore_guest_fpustate(struct vcpu *vcpu)
{
	register_t s;

	s = intr_disable();
	fpu_stop_emulating();
	fxrstor(&vcpu->savefpu);
	fpu_start_emulating();
	intr_restore(s);
}

static void
save_guest_fpustate(struct vcpu *vcpu)
{
	register_t s;

	s = intr_disable();
	fpu_stop_emulating();
	fxsave(&vcpu->savefpu);
	fpu_start_emulating();
	intr_restore(s);
}

int
vm_run(struct vm *vm, struct vm_run *vmrun)
{
	int error, vcpuid;
	struct vcpu *vcpu;
	struct pcb *pcb;
	uint64_t tscval;

	vcpuid = vmrun->cpuid;

	if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
		return (EINVAL);

	vcpu = &vm->vcpu[vcpuid];

	critical_enter();

	tscval = rdtsc();

	pcb = PCPU_GET(curpcb);
	set_pcb_flags(pcb, PCB_FULL_IRET);

	vcpu->hostcpu = curcpu;

	fpuexit(curthread);
	restore_guest_msrs(vm, vcpuid);
	restore_guest_fpustate(vcpu);
	error = VMRUN(vm->cookie, vcpuid, vmrun->rip, &vmrun->vm_exit);
	save_guest_fpustate(vcpu);
	restore_host_msrs(vm, vcpuid);

	vmm_stat_incr(vm, vcpuid, VCPU_TOTAL_RUNTIME, rdtsc() - tscval);

	critical_exit();

	return (error);
}

int
vm_inject_event(struct vm *vm, int vcpuid, int type,
		int vector, uint32_t code, int code_valid)
{
	if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
		return (EINVAL);

	if ((type > VM_EVENT_NONE && type < VM_EVENT_MAX) == 0)
		return (EINVAL);

	if (vector < 0 || vector > 255)
		return (EINVAL);

	return (VMINJECT(vm->cookie, vcpuid, type, vector, code, code_valid));
}

int
vm_inject_nmi(struct vm *vm, int vcpu)
{
	int error;

	if (vcpu < 0 || vcpu >= VM_MAXCPU)
		return (EINVAL);

	error = VMNMI(vm->cookie, vcpu);
	vm_interrupt_hostcpu(vm, vcpu);
	return (error);
}

int
vm_get_capability(struct vm *vm, int vcpu, int type, int *retval)
{
	if (vcpu < 0 || vcpu >= VM_MAXCPU)
		return (EINVAL);

	if (type < 0 || type >= VM_CAP_MAX)
		return (EINVAL);

	return (VMGETCAP(vm->cookie, vcpu, type, retval));
}

int
vm_set_capability(struct vm *vm, int vcpu, int type, int val)
{
	if (vcpu < 0 || vcpu >= VM_MAXCPU)
		return (EINVAL);

	if (type < 0 || type >= VM_CAP_MAX)
		return (EINVAL);

	return (VMSETCAP(vm->cookie, vcpu, type, val));
}

uint64_t *
vm_guest_msrs(struct vm *vm, int cpu)
{
	return (vm->vcpu[cpu].guest_msrs);
}

struct vlapic *
vm_lapic(struct vm *vm, int cpu)
{
	return (vm->vcpu[cpu].vlapic);
}

boolean_t
vmm_is_pptdev(int bus, int slot, int func)
{
	int found, b, s, f, n;
	char *val, *cp, *cp2;

	/*
	 * setenv pptdevs "1/2/3 4/5/6 7/8/9 10/11/12"
	 */
	found = 0;
	cp = val = getenv("pptdevs");
	while (cp != NULL && *cp != '\0') {
		if ((cp2 = strchr(cp, ' ')) != NULL)
			*cp2 = '\0';

		n = sscanf(cp, "%d/%d/%d", &b, &s, &f);
		if (n == 3 && bus == b && slot == s && func == f) {
			found = 1;
			break;
		}
		
		if (cp2 != NULL)
			*cp2++ = ' ';

		cp = cp2;
	}
	freeenv(val);
	return (found);
}

void *
vm_iommu_domain(struct vm *vm)
{

	return (vm->iommu);
}

void
vm_set_run_state(struct vm *vm, int vcpuid, int state)
{
	struct vcpu *vcpu;

	if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
		panic("vm_set_run_state: invalid vcpuid %d", vcpuid);

	vcpu = &vm->vcpu[vcpuid];

	if (state == VCPU_RUNNING) {
		if (vcpu->flags & VCPU_F_RUNNING) {
			panic("vm_set_run_state: %s[%d] is already running",
			      vm_name(vm), vcpuid);
		}
		vcpu->flags |= VCPU_F_RUNNING;
	} else {
		if ((vcpu->flags & VCPU_F_RUNNING) == 0) {
			panic("vm_set_run_state: %s[%d] is already stopped",
			      vm_name(vm), vcpuid);
		}
		vcpu->flags &= ~VCPU_F_RUNNING;
	}
}

int
vm_get_run_state(struct vm *vm, int vcpuid, int *cpuptr)
{
	int retval, hostcpu;
	struct vcpu *vcpu;

	if (vcpuid < 0 || vcpuid >= VM_MAXCPU)
		panic("vm_get_run_state: invalid vcpuid %d", vcpuid);

	vcpu = &vm->vcpu[vcpuid];
	if (vcpu->flags & VCPU_F_RUNNING) {
		retval = VCPU_RUNNING;
		hostcpu = vcpu->hostcpu;
	} else {
		retval = VCPU_STOPPED;
		hostcpu = -1;
	}

	if (cpuptr)
		*cpuptr = hostcpu;

	return (retval);
}

void
vm_activate_cpu(struct vm *vm, int vcpuid)
{

	if (vcpuid >= 0 && vcpuid < VM_MAXCPU)
		CPU_SET(vcpuid, &vm->active_cpus);
}

cpuset_t
vm_active_cpus(struct vm *vm)
{

	return (vm->active_cpus);
}

void *
vcpu_stats(struct vm *vm, int vcpuid)
{

	return (vm->vcpu[vcpuid].stats);
}