Commit 2eeb2e94 authored by Gregory Haskins's avatar Gregory Haskins Committed by Avi Kivity

KVM: Adds support for in-kernel mmio handlers

Signed-off-by: default avatarGregory Haskins <ghaskins@novell.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent d9413cd7
......@@ -265,6 +265,65 @@ struct kvm_stat {
u32 efer_reload;
};
struct kvm_io_device {
void (*read)(struct kvm_io_device *this,
gpa_t addr,
int len,
void *val);
void (*write)(struct kvm_io_device *this,
gpa_t addr,
int len,
const void *val);
int (*in_range)(struct kvm_io_device *this, gpa_t addr);
void (*destructor)(struct kvm_io_device *this);
void *private;
};
static inline void kvm_iodevice_read(struct kvm_io_device *dev,
gpa_t addr,
int len,
void *val)
{
dev->read(dev, addr, len, val);
}
static inline void kvm_iodevice_write(struct kvm_io_device *dev,
gpa_t addr,
int len,
const void *val)
{
dev->write(dev, addr, len, val);
}
static inline int kvm_iodevice_inrange(struct kvm_io_device *dev, gpa_t addr)
{
return dev->in_range(dev, addr);
}
static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
{
dev->destructor(dev);
}
/*
* It would be nice to use something smarter than a linear search, TBD...
* Thankfully we dont expect many devices to register (famous last words :),
* so until then it will suffice. At least its abstracted so we can change
* in one place.
*/
struct kvm_io_bus {
int dev_count;
#define NR_IOBUS_DEVS 6
struct kvm_io_device *devs[NR_IOBUS_DEVS];
};
void kvm_io_bus_init(struct kvm_io_bus *bus);
void kvm_io_bus_destroy(struct kvm_io_bus *bus);
struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus, gpa_t addr);
void kvm_io_bus_register_dev(struct kvm_io_bus *bus,
struct kvm_io_device *dev);
struct kvm_vcpu {
struct kvm *kvm;
union {
......@@ -393,6 +452,7 @@ struct kvm {
unsigned long rmap_overflow;
struct list_head vm_list;
struct file *filp;
struct kvm_io_bus mmio_bus;
};
struct descriptor_table {
......
......@@ -366,6 +366,7 @@ static struct kvm *kvm_create_vm(void)
spin_lock(&kvm_lock);
list_add(&kvm->vm_list, &vm_list);
spin_unlock(&kvm_lock);
kvm_io_bus_init(&kvm->mmio_bus);
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
struct kvm_vcpu *vcpu = &kvm->vcpus[i];
......@@ -474,6 +475,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
spin_lock(&kvm_lock);
list_del(&kvm->vm_list);
spin_unlock(&kvm_lock);
kvm_io_bus_destroy(&kvm->mmio_bus);
kvm_free_vcpus(kvm);
kvm_free_physmem(kvm);
kfree(kvm);
......@@ -1097,12 +1099,25 @@ static int emulator_write_std(unsigned long addr,
return X86EMUL_UNHANDLEABLE;
}
static struct kvm_io_device *vcpu_find_mmio_dev(struct kvm_vcpu *vcpu,
gpa_t addr)
{
/*
* Note that its important to have this wrapper function because
* in the very near future we will be checking for MMIOs against
* the LAPIC as well as the general MMIO bus
*/
return kvm_io_bus_find_dev(&vcpu->kvm->mmio_bus, addr);
}
static int emulator_read_emulated(unsigned long addr,
void *val,
unsigned int bytes,
struct x86_emulate_ctxt *ctxt)
{
struct kvm_vcpu *vcpu = ctxt->vcpu;
struct kvm_vcpu *vcpu = ctxt->vcpu;
struct kvm_io_device *mmio_dev;
gpa_t gpa;
if (vcpu->mmio_read_completed) {
memcpy(val, vcpu->mmio_data, bytes);
......@@ -1111,18 +1126,26 @@ static int emulator_read_emulated(unsigned long addr,
} else if (emulator_read_std(addr, val, bytes, ctxt)
== X86EMUL_CONTINUE)
return X86EMUL_CONTINUE;
else {
gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
if (gpa == UNMAPPED_GVA)
return X86EMUL_PROPAGATE_FAULT;
vcpu->mmio_needed = 1;
vcpu->mmio_phys_addr = gpa;
vcpu->mmio_size = bytes;
vcpu->mmio_is_write = 0;
gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
if (gpa == UNMAPPED_GVA)
return X86EMUL_PROPAGATE_FAULT;
return X86EMUL_UNHANDLEABLE;
/*
* Is this MMIO handled locally?
*/
mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
if (mmio_dev) {
kvm_iodevice_read(mmio_dev, gpa, bytes, val);
return X86EMUL_CONTINUE;
}
vcpu->mmio_needed = 1;
vcpu->mmio_phys_addr = gpa;
vcpu->mmio_size = bytes;
vcpu->mmio_is_write = 0;
return X86EMUL_UNHANDLEABLE;
}
static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
......@@ -1150,8 +1173,9 @@ static int emulator_write_emulated(unsigned long addr,
unsigned int bytes,
struct x86_emulate_ctxt *ctxt)
{
struct kvm_vcpu *vcpu = ctxt->vcpu;
gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
struct kvm_vcpu *vcpu = ctxt->vcpu;
struct kvm_io_device *mmio_dev;
gpa_t gpa = vcpu->mmu.gva_to_gpa(vcpu, addr);
if (gpa == UNMAPPED_GVA) {
kvm_arch_ops->inject_page_fault(vcpu, addr, 2);
......@@ -1161,6 +1185,15 @@ static int emulator_write_emulated(unsigned long addr,
if (emulator_write_phys(vcpu, gpa, val, bytes))
return X86EMUL_CONTINUE;
/*
* Is this MMIO handled locally?
*/
mmio_dev = vcpu_find_mmio_dev(vcpu, gpa);
if (mmio_dev) {
kvm_iodevice_write(mmio_dev, gpa, bytes, val);
return X86EMUL_CONTINUE;
}
vcpu->mmio_needed = 1;
vcpu->mmio_phys_addr = gpa;
vcpu->mmio_size = bytes;
......@@ -3031,6 +3064,43 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
return NOTIFY_OK;
}
void kvm_io_bus_init(struct kvm_io_bus *bus)
{
memset(bus, 0, sizeof(*bus));
}
void kvm_io_bus_destroy(struct kvm_io_bus *bus)
{
int i;
for (i = 0; i < bus->dev_count; i++) {
struct kvm_io_device *pos = bus->devs[i];
kvm_iodevice_destructor(pos);
}
}
struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus, gpa_t addr)
{
int i;
for (i = 0; i < bus->dev_count; i++) {
struct kvm_io_device *pos = bus->devs[i];
if (pos->in_range(pos, addr))
return pos;
}
return NULL;
}
void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
{
BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
bus->devs[bus->dev_count++] = dev;
}
static struct notifier_block kvm_cpu_notifier = {
.notifier_call = kvm_cpu_hotplug,
.priority = 20, /* must be > scheduler priority */
......
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