[PATCHv5 5/6] kvm: remove in_range from io devices

Michael S. Tsirkin
2009-06-29T19:26:13Z

This changes bus accesses to use high-level kvm_io_bus_read/kvm_io_bus_write
functions. in_range now becomes unused so it is removed from device ops in
favor of read/write callbacks performing range checks internally.

This allows aliasing (mostly for in-kernel virtio), as well as better error
handling by making it possible to pass errors up to userspace.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
arch/ia64/kvm/kvm-ia64.c | 28 +++--------
arch/x86/kvm/i8254.c | 49 +++++++++++---------
arch/x86/kvm/i8259.c | 20 +++++---
arch/x86/kvm/lapic.c | 44 ++++++++----------
arch/x86/kvm/x86.c | 110 +++++++++++++--------------------------------
include/linux/kvm_host.h | 6 ++-
virt/kvm/coalesced_mmio.c | 16 +++----
virt/kvm/ioapic.c | 22 +++++----
virt/kvm/iodev.h | 39 ++++++----------
virt/kvm/kvm_main.c | 26 +++++++----
10 files changed, 152 insertions(+), 208 deletions(-)

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index c1c5cb6..8054d7b 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -210,16 +210,6 @@ int kvm_dev_ioctl_check_extension(long ext)

}

-static struct kvm_io_device *vcpu_find_mmio_dev(struct kvm_vcpu *vcpu,
- gpa_t addr, int len, int is_write)
-{
- struct kvm_io_device *dev;
-
- dev = kvm_io_bus_find_dev(&vcpu->kvm->mmio_bus, addr, len, is_write);
-
- return dev;
-}
-
static int handle_vm_error(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
kvm_run->exit_reason = KVM_EXIT_UNKNOWN;
@@ -231,6 +221,7 @@ static int handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
struct kvm_mmio_req *p;
struct kvm_io_device *mmio_dev;
+ int r;

p = kvm_get_vcpu_ioreq(vcpu);

@@ -247,16 +238,13 @@ static int handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_run->exit_reason = KVM_EXIT_MMIO;
return 0;
mmio:
- mmio_dev = vcpu_find_mmio_dev(vcpu, p->addr, p->size, !p->dir);
- if (mmio_dev) {
- if (!p->dir)
- kvm_iodevice_write(mmio_dev, p->addr, p->size,
- &p->data);
- else
- kvm_iodevice_read(mmio_dev, p->addr, p->size,
- &p->data);
-
- } else
+ if (p->dir)
+ r = kvm_io_bus_read(&vcpu->kvm->mmio_bus, p->addr,
+ p->size, &p->data);
+ else
+ r = kvm_io_bus_write(&vcpu->kvm->mmio_bus, p->addr,
+ p->size, &p->data);
+ if (r)
printk(KERN_ERR"kvm: No iodevice found! addr:%lx\n", p->addr);
p->state = STATE_IORESP_READY;

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index cc0c10d..0c70b4b 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -357,8 +357,14 @@ static inline struct kvm_pit *speaker_to_pit(struct kvm_io_device *dev)
return container_of(dev, struct kvm_pit, speaker_dev);
}

-static void pit_ioport_write(struct kvm_io_device *this,
- gpa_t addr, int len, const void *data)
+static inline int pit_in_range(gpa_t addr)
+{
+ return ((addr >= KVM_PIT_BASE_ADDRESS) &&
+ (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH));
+}
+
+static int pit_ioport_write(struct kvm_io_device *this,
+ gpa_t addr, int len, const void *data)
{
struct kvm_pit *pit = dev_to_pit(this);
struct kvm_kpit_state *pit_state = &pit->pit_state;
@@ -366,6 +372,8 @@ static void pit_ioport_write(struct kvm_io_device *this,
int channel, access;
struct kvm_kpit_channel_state *s;
u32 val = *(u32 *) data;
+ if (!pit_in_range(addr))
+ return -EOPNOTSUPP;

val &= 0xff;
addr &= KVM_PIT_CHANNEL_MASK;
@@ -428,16 +436,19 @@ static void pit_ioport_write(struct kvm_io_device *this,
}

mutex_unlock(&pit_state->lock);
+ return 0;
}

-static void pit_ioport_read(struct kvm_io_device *this,
- gpa_t addr, int len, void *data)
+static int pit_ioport_read(struct kvm_io_device *this,
+ gpa_t addr, int len, void *data)
{
struct kvm_pit *pit = dev_to_pit(this);
struct kvm_kpit_state *pit_state = &pit->pit_state;
struct kvm *kvm = pit->kvm;
int ret, count;
struct kvm_kpit_channel_state *s;
+ if (!pit_in_range(addr))
+ return -EOPNOTSUPP;

addr &= KVM_PIT_CHANNEL_MASK;
s = &pit_state->channels[addr];
@@ -492,37 +503,36 @@ static void pit_ioport_read(struct kvm_io_device *this,
memcpy(data, (char *)&ret, len);

mutex_unlock(&pit_state->lock);
+ return 0;
}

-static int pit_in_range(struct kvm_io_device *this, gpa_t addr,
- int len, int is_write)
-{
- return ((addr >= KVM_PIT_BASE_ADDRESS) &&
- (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH));
-}
-
-static void speaker_ioport_write(struct kvm_io_device *this,
- gpa_t addr, int len, const void *data)
+static int speaker_ioport_write(struct kvm_io_device *this,
+ gpa_t addr, int len, const void *data)
{
struct kvm_pit *pit = speaker_to_pit(this);
struct kvm_kpit_state *pit_state = &pit->pit_state;
struct kvm *kvm = pit->kvm;
u32 val = *(u32 *) data;
+ if (addr != KVM_SPEAKER_BASE_ADDRESS)
+ return -EOPNOTSUPP;

mutex_lock(&pit_state->lock);
pit_state->speaker_data_on = (val >> 1) & 1;
pit_set_gate(kvm, 2, val & 1);
mutex_unlock(&pit_state->lock);
+ return 0;
}

-static void speaker_ioport_read(struct kvm_io_device *this,
- gpa_t addr, int len, void *data)
+static int speaker_ioport_read(struct kvm_io_device *this,
+ gpa_t addr, int len, void *data)
{
struct kvm_pit *pit = speaker_to_pit(this);
struct kvm_kpit_state *pit_state = &pit->pit_state;
struct kvm *kvm = pit->kvm;
unsigned int refresh_clock;
int ret;
+ if (addr != KVM_SPEAKER_BASE_ADDRESS)
+ return -EOPNOTSUPP;

/* Refresh clock toggles at about 15us. We approximate as 2^14ns. */
refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1;
@@ -534,12 +544,7 @@ static void speaker_ioport_read(struct kvm_io_device *this,
len = sizeof(ret);
memcpy(data, (char *)&ret, len);
mutex_unlock(&pit_state->lock);
-}
-
-static int speaker_in_range(struct kvm_io_device *this, gpa_t addr,
- int len, int is_write)
-{
- return (addr == KVM_SPEAKER_BASE_ADDRESS);
+ return 0;
}

void kvm_pit_reset(struct kvm_pit *pit)
@@ -573,13 +578,11 @@ static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask)
static const struct kvm_io_device_ops pit_dev_ops = {
.read = pit_ioport_read,
.write = pit_ioport_write,
- .in_range = pit_in_range,
};

static const struct kvm_io_device_ops speaker_dev_ops = {
.read = speaker_ioport_read,
.write = speaker_ioport_write,
- .in_range = speaker_in_range,
};

/* Caller must have writers lock on slots_lock */
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 1851aec..1d1bb75 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -430,8 +430,7 @@ static u32 elcr_ioport_read(void *opaque, u32 addr1)
return s->elcr;
}

-static int picdev_in_range(struct kvm_io_device *this, gpa_t addr,
- int len, int is_write)
+static int picdev_in_range(gpa_t addr)
{
switch (addr) {
case 0x20:
@@ -451,16 +450,18 @@ static inline struct kvm_pic *to_pic(struct kvm_io_device *dev)
return container_of(dev, struct kvm_pic, dev);
}

-static void picdev_write(struct kvm_io_device *this,
+static int picdev_write(struct kvm_io_device *this,
gpa_t addr, int len, const void *val)
{
struct kvm_pic *s = to_pic(this);
unsigned char data = *(unsigned char *)val;
+ if (!picdev_in_range(addr))
+ return -EOPNOTSUPP;

if (len != 1) {
if (printk_ratelimit())
printk(KERN_ERR "PIC: non byte write\n");
- return;
+ return 0;
}
pic_lock(s);
switch (addr) {
@@ -476,18 +477,21 @@ static void picdev_write(struct kvm_io_device *this,
break;
}
pic_unlock(s);
+ return 0;
}

-static void picdev_read(struct kvm_io_device *this,
- gpa_t addr, int len, void *val)
+static int picdev_read(struct kvm_io_device *this,
+ gpa_t addr, int len, void *val)
{
struct kvm_pic *s = to_pic(this);
unsigned char data = 0;
+ if (!picdev_in_range(addr))
+ return -EOPNOTSUPP;

if (len != 1) {
if (printk_ratelimit())
printk(KERN_ERR "PIC: non byte read\n");
- return;
+ return 0;
}
pic_lock(s);
switch (addr) {
@@ -504,6 +508,7 @@ static void picdev_read(struct kvm_io_device *this,
}
*(unsigned char *)val = data;
pic_unlock(s);
+ return 0;
}

/*
@@ -526,7 +531,6 @@ static void pic_irq_request(void *opaque, int level)
static const struct kvm_io_device_ops picdev_ops = {
.read = picdev_read,
.write = picdev_write,
- .in_range = picdev_in_range,
};

struct kvm_pic *kvm_create_pic(struct kvm *kvm)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 2e02865..265a765 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -546,18 +546,27 @@ static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev)
return container_of(dev, struct kvm_lapic, dev);
}

-static void apic_mmio_read(struct kvm_io_device *this,
- gpa_t address, int len, void *data)
+static int apic_mmio_in_range(struct kvm_lapic *apic, gpa_t addr)
+{
+ return apic_hw_enabled(apic) &&
+ addr >= apic->base_address &&
+ addr < apic->base_address + LAPIC_MMIO_LENGTH;
+}
+
+static int apic_mmio_read(struct kvm_io_device *this,
+ gpa_t address, int len, void *data)
{
struct kvm_lapic *apic = to_lapic(this);
unsigned int offset = address - apic->base_address;
unsigned char alignment = offset & 0xf;
u32 result;
+ if (!apic_mmio_in_range(apic, address))
+ return -EOPNOTSUPP;

if ((alignment + len) > 4) {
printk(KERN_ERR "KVM_APIC_READ: alignment error %lx %d",
(unsigned long)address, len);
- return;
+ return 0;
}
result = __apic_read(apic, offset & ~0xf);

@@ -574,6 +583,7 @@ static void apic_mmio_read(struct kvm_io_device *this,
"should be 1,2, or 4 instead\n", len);
break;
}
+ return 0;
}

static void update_divide_count(struct kvm_lapic *apic)
@@ -629,13 +639,15 @@ static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
apic->vcpu->kvm->arch.vapics_in_nmi_mode--;
}

-static void apic_mmio_write(struct kvm_io_device *this,
- gpa_t address, int len, const void *data)
+static int apic_mmio_write(struct kvm_io_device *this,
+ gpa_t address, int len, const void *data)
{
struct kvm_lapic *apic = to_lapic(this);
unsigned int offset = address - apic->base_address;
unsigned char alignment = offset & 0xf;
u32 val;
+ if (!apic_mmio_in_range(apic, address))
+ return -EOPNOTSUPP;

/*
* APIC register must be aligned on 128-bits boundary.
@@ -646,7 +658,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
/* Don't shout loud, $infamous_os would cause only noise. */
apic_debug("apic write: bad size=%d %lx\n",
len, (long)address);
- return;
+ return 0;
}

val = *(u32 *) data;
@@ -729,7 +741,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
hrtimer_cancel(&apic->lapic_timer.timer);
apic_set_reg(apic, APIC_TMICT, val);
start_apic_timer(apic);
- return;
+ return 0;

case APIC_TDCR:
if (val & 4)
@@ -743,22 +755,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
offset);
break;
}
-
-}
-
-static int apic_mmio_range(struct kvm_io_device *this, gpa_t addr,
- int len, int size)
-{
- struct kvm_lapic *apic = to_lapic(this);
- int ret = 0;
-
-
- if (apic_hw_enabled(apic) &&
- (addr >= apic->base_address) &&
- (addr < (apic->base_address + LAPIC_MMIO_LENGTH)))
- ret = 1;
-
- return ret;
+ return 0;
}

void kvm_free_lapic(struct kvm_vcpu *vcpu)
@@ -938,7 +935,6 @@ static struct kvm_timer_ops lapic_timer_ops = {
static const struct kvm_io_device_ops apic_mmio_ops = {
.read = apic_mmio_read,
.write = apic_mmio_write,
- .in_range = apic_mmio_range,
};

int kvm_create_lapic(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a2505ca..4c171e8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2260,35 +2260,23 @@ static void kvm_init_msr_list(void)
num_msrs_to_save = j;
}

-/*
- * Only apic need an MMIO device hook, so shortcut now..
- */
-static struct kvm_io_device *vcpu_find_pervcpu_dev(struct kvm_vcpu *vcpu,
- gpa_t addr, int len,
- int is_write)
+static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len,
+ const void *v)
{
- struct kvm_io_device *dev;
+ if (vcpu->arch.apic &&
+ !kvm_iodevice_write(&vcpu->arch.apic->dev, addr, len, v))
+ return 0;

- if (vcpu->arch.apic) {
- dev = &vcpu->arch.apic->dev;
- if (kvm_iodevice_in_range(dev, addr, len, is_write))
- return dev;
- }
- return NULL;
+ return kvm_io_bus_write(&vcpu->kvm->mmio_bus, addr, len, v);
}

-
-static struct kvm_io_device *vcpu_find_mmio_dev(struct kvm_vcpu *vcpu,
- gpa_t addr, int len,
- int is_write)
+static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v)
{
- struct kvm_io_device *dev;
+ if (vcpu->arch.apic &&
+ !kvm_iodevice_read(&vcpu->arch.apic->dev, addr, len, v))
+ return 0;

- dev = vcpu_find_pervcpu_dev(vcpu, addr, len, is_write);
- if (dev == NULL)
- dev = kvm_io_bus_find_dev(&vcpu->kvm->mmio_bus, addr, len,
- is_write);
- return dev;
+ return kvm_io_bus_read(&vcpu->kvm->mmio_bus, addr, len, v);
}

static int kvm_read_guest_virt(gva_t addr, void *val, unsigned int bytes,
@@ -2357,7 +2345,6 @@ static int emulator_read_emulated(unsigned long addr,
unsigned int bytes,
struct kvm_vcpu *vcpu)
{
- struct kvm_io_device *mmio_dev;
gpa_t gpa;

if (vcpu->mmio_read_completed) {
@@ -2382,13 +2369,8 @@ mmio:
/*
* Is this MMIO handled locally?
*/
- mutex_lock(&vcpu->kvm->lock);
- mmio_dev = vcpu_find_mmio_dev(vcpu, gpa, bytes, 0);
- mutex_unlock(&vcpu->kvm->lock);
- if (mmio_dev) {
- kvm_iodevice_read(mmio_dev, gpa, bytes, val);
+ if (!vcpu_mmio_read(vcpu, gpa, bytes, val))
return X86EMUL_CONTINUE;
- }

vcpu->mmio_needed = 1;
vcpu->mmio_phys_addr = gpa;
@@ -2415,7 +2397,6 @@ static int emulator_write_emulated_onepage(unsigned long addr,
unsigned int bytes,
struct kvm_vcpu *vcpu)
{
- struct kvm_io_device *mmio_dev;
gpa_t gpa;

gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, addr);
@@ -2436,13 +2417,8 @@ mmio:
/*
* Is this MMIO handled locally?
*/
- mutex_lock(&vcpu->kvm->lock);
- mmio_dev = vcpu_find_mmio_dev(vcpu, gpa, bytes, 1);
- mutex_unlock(&vcpu->kvm->lock);
- if (mmio_dev) {
- kvm_iodevice_write(mmio_dev, gpa, bytes, val);
+ if (!vcpu_mmio_write(vcpu, gpa, bytes, val))
return X86EMUL_CONTINUE;
- }

vcpu->mmio_needed = 1;
vcpu->mmio_phys_addr = gpa;
@@ -2758,48 +2734,40 @@ int complete_pio(struct kvm_vcpu *vcpu)
return 0;
}

-static void kernel_pio(struct kvm_io_device *pio_dev,
- struct kvm_vcpu *vcpu,
- void *pd)
+static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
{
/* TODO: String I/O for in kernel device */
+ int r;

if (vcpu->arch.pio.in)
- kvm_iodevice_read(pio_dev, vcpu->arch.pio.port,
- vcpu->arch.pio.size,
- pd);
+ r = kvm_io_bus_read(&vcpu->kvm->pio_bus, vcpu->arch.pio.port,
+ vcpu->arch.pio.size, pd);
else
- kvm_iodevice_write(pio_dev, vcpu->arch.pio.port,
- vcpu->arch.pio.size,
- pd);
+ r = kvm_io_bus_write(&vcpu->kvm->pio_bus, vcpu->arch.pio.port,
+ vcpu->arch.pio.size, pd);
+ return r;
}

-static void pio_string_write(struct kvm_io_device *pio_dev,
- struct kvm_vcpu *vcpu)
+static int pio_string_write(struct kvm_vcpu *vcpu)
{
struct kvm_pio_request *io = &vcpu->arch.pio;
void *pd = vcpu->arch.pio_data;
- int i;
+ int i, r = 0;

for (i = 0; i < io->cur_count; i++) {
- kvm_iodevice_write(pio_dev, io->port,
- io->size,
- pd);
+ if (kvm_io_bus_write(&vcpu->kvm->pio_bus,
+ io->port, io->size, pd)) {
+ r = -EOPNOTSUPP;
+ break;
+ }
pd += io->size;
}
-}
-
-static struct kvm_io_device *vcpu_find_pio_dev(struct kvm_vcpu *vcpu,
- gpa_t addr, int len,
- int is_write)
-{
- return kvm_io_bus_find_dev(&vcpu->kvm->pio_bus, addr, len, is_write);
+ return r;
}

int kvm_emulate_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
int size, unsigned port)
{
- struct kvm_io_device *pio_dev;
unsigned long val;

vcpu->run->exit_reason = KVM_EXIT_IO;
@@ -2819,11 +2787,7 @@ int kvm_emulate_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
val = kvm_register_read(vcpu, VCPU_REGS_RAX);
memcpy(vcpu->arch.pio_data, &val, 4);

- mutex_lock(&vcpu->kvm->lock);
- pio_dev = vcpu_find_pio_dev(vcpu, port, size, !in);
- mutex_unlock(&vcpu->kvm->lock);
- if (pio_dev) {
- kernel_pio(pio_dev, vcpu, vcpu->arch.pio_data);
+ if (!kernel_pio(vcpu, vcpu->arch.pio_data)) {
complete_pio(vcpu);
return 1;
}
@@ -2837,7 +2801,6 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
{
unsigned now, in_page;
int ret = 0;
- struct kvm_io_device *pio_dev;

vcpu->run->exit_reason = KVM_EXIT_IO;
vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
@@ -2881,12 +2844,6 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,

vcpu->arch.pio.guest_gva = address;

- mutex_lock(&vcpu->kvm->lock);
- pio_dev = vcpu_find_pio_dev(vcpu, port,
- vcpu->arch.pio.cur_count,
- !vcpu->arch.pio.in);
- mutex_unlock(&vcpu->kvm->lock);
-
if (!vcpu->arch.pio.in) {
/* string PIO write */
ret = pio_copy_data(vcpu);
@@ -2894,16 +2851,13 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
kvm_inject_gp(vcpu, 0);
return 1;
}
- if (ret == 0 && pio_dev) {
- pio_string_write(pio_dev, vcpu);
+ if (ret == 0 && !pio_string_write(vcpu)) {
complete_pio(vcpu);
if (vcpu->arch.pio.count == 0)
ret = 1;
}
- } else if (pio_dev)
- pr_unimpl(vcpu, "no string pio read support yet, "
- "port %x size %d count %ld\n",
- port, size, count);
+ }
+ /* no string PIO read support yet */

return ret;
}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 889b608..3f95332 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -60,8 +60,10 @@ struct kvm_io_bus {

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, int len, int is_write);
+int kvm_io_bus_write(struct kvm_io_bus *bus, gpa_t addr, int len,
+ const void *val);
+int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len,
+ void *val);
void __kvm_io_bus_register_dev(struct kvm_io_bus *bus,
struct kvm_io_device *dev);
void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus,
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 7b7cc9f..0352f81 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -19,18 +19,14 @@ static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev)
return container_of(dev, struct kvm_coalesced_mmio_dev, dev);
}

-static int coalesced_mmio_in_range(struct kvm_io_device *this,
- gpa_t addr, int len, int is_write)
+static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
+ gpa_t addr, int len)
{
- struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
struct kvm_coalesced_mmio_zone *zone;
struct kvm_coalesced_mmio_ring *ring;
unsigned avail;
int i;

- if (!is_write)
- return 0;
-
/* Are we able to batch it ? */

/* last is the first free entry
@@ -60,11 +56,13 @@ static int coalesced_mmio_in_range(struct kvm_io_device *this,
return 0;
}

-static void coalesced_mmio_write(struct kvm_io_device *this,
- gpa_t addr, int len, const void *val)
+static int coalesced_mmio_write(struct kvm_io_device *this,
+ gpa_t addr, int len, const void *val)
{
struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring;
+ if (!coalesced_mmio_in_range(dev, addr, len))
+ return -EOPNOTSUPP;

spin_lock(&dev->lock);

@@ -76,6 +74,7 @@ static void coalesced_mmio_write(struct kvm_io_device *this,
smp_wmb();
ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX;
spin_unlock(&dev->lock);
+ return 0;
}

static void coalesced_mmio_destructor(struct kvm_io_device *this)
@@ -87,7 +86,6 @@ static void coalesced_mmio_destructor(struct kvm_io_device *this)

static const struct kvm_io_device_ops coalesced_mmio_ops = {
.write = coalesced_mmio_write,
- .in_range = coalesced_mmio_in_range,
.destructor = coalesced_mmio_destructor,
};

diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index ad80ead..e4deae0 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -227,20 +227,19 @@ static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
return container_of(dev, struct kvm_ioapic, dev);
}

-static int ioapic_in_range(struct kvm_io_device *this, gpa_t addr,
- int len, int is_write)
+static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
{
- struct kvm_ioapic *ioapic = to_ioapic(this);
-
return ((addr >= ioapic->base_address &&
(addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
}

-static void ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
- void *val)
+static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
+ void *val)
{
struct kvm_ioapic *ioapic = to_ioapic(this);
u32 result;
+ if (!ioapic_in_range(ioapic, addr))
+ return -EOPNOTSUPP;

ioapic_debug("addr %lx\n", (unsigned long)addr);
ASSERT(!(addr & 0xf)); /* check alignment */
@@ -273,13 +272,16 @@ static void ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
printk(KERN_WARNING "ioapic: wrong length %d\n", len);
}
mutex_unlock(&ioapic->kvm->irq_lock);
+ return 0;
}

-static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
- const void *val)
+static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
+ const void *val)
{
struct kvm_ioapic *ioapic = to_ioapic(this);
u32 data;
+ if (!ioapic_in_range(ioapic, addr))
+ return -EOPNOTSUPP;

ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
(void*)addr, len, val);
@@ -290,7 +292,7 @@ static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
data = *(u32 *) val;
else {
printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
- return;
+ return 0;
}

addr &= 0xff;
@@ -312,6 +314,7 @@ static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
break;
}
mutex_unlock(&ioapic->kvm->irq_lock);
+ return 0;
}

void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
@@ -329,7 +332,6 @@ void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
static const struct kvm_io_device_ops ioapic_mmio_ops = {
.read = ioapic_mmio_read,
.write = ioapic_mmio_write,
- .in_range = ioapic_in_range,
};

int kvm_ioapic_init(struct kvm *kvm)
diff --git a/virt/kvm/iodev.h b/virt/kvm/iodev.h
index 06e38b2..12fd3ca 100644
--- a/virt/kvm/iodev.h
+++ b/virt/kvm/iodev.h
@@ -17,23 +17,24 @@
#define __KVM_IODEV_H__

#include <linux/kvm_types.h>
+#include <asm/errno.h>

struct kvm_io_device;

/**
* kvm_io_device_ops are called under kvm slots_lock.
+ * read and write handlers return 0 if the transaction has been handled,
+ * or non-zero to have it passed to the next device.
**/
struct kvm_io_device_ops {
- void (*read)(struct kvm_io_device *this,
+ int (*read)(struct kvm_io_device *this,
+ gpa_t addr,
+ int len,
+ void *val);
+ int (*write)(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, int len,
- int is_write);
+ const void *val);
void (*destructor)(struct kvm_io_device *this);
};

@@ -48,26 +49,16 @@ static inline void kvm_iodevice_init(struct kvm_io_device *dev,
dev->ops = ops;
}

-static inline void kvm_iodevice_read(struct kvm_io_device *dev,
- gpa_t addr,
- int len,
- void *val)
+static inline int kvm_iodevice_read(struct kvm_io_device *dev,
+ gpa_t addr, int l, void *v)
{
- dev->ops->read(dev, addr, len, val);
+ return dev->ops->read ? dev->ops->read(dev, addr, l, v) : -EOPNOTSUPP;
}

-static inline void kvm_iodevice_write(struct kvm_io_device *dev,
- gpa_t addr,
- int len,
- const void *val)
+static inline int kvm_iodevice_write(struct kvm_io_device *dev,
+ gpa_t addr, int l, const void *v)
{
- dev->ops->write(dev, addr, len, val);
-}
-
-static inline int kvm_iodevice_in_range(struct kvm_io_device *dev,
- gpa_t addr, int len, int is_write)
-{
- return dev->ops->in_range(dev, addr, len, is_write);
+ return dev->ops->write ? dev->ops->write(dev, addr, l, v) : -EOPNOTSUPP;
}

static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7cae1b7..728118f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2484,19 +2484,25 @@ 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, int len, int is_write)
+/* kvm_io_bus_write - called under kvm->slots_lock */
+int kvm_io_bus_write(struct kvm_io_bus *bus, gpa_t addr,
+ int len, const void *val)
{
int i;
+ for (i = 0; i < bus->dev_count; i++)
+ if (!kvm_iodevice_write(bus->devs[i], addr, len, val))
+ return 0;
+ return -EOPNOTSUPP;
+}

- for (i = 0; i < bus->dev_count; i++) {
- struct kvm_io_device *pos = bus->devs[i];
-
- if (kvm_iodevice_in_range(pos, addr, len, is_write))
- return pos;
- }
-
- return NULL;
+/* kvm_io_bus_read - called under kvm->slots_lock */
+int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len, void *val)
+{
+ int i;
+ for (i = 0; i < bus->dev_count; i++)
+ if (!kvm_iodevice_read(bus->devs[i], addr, len, val))
+ return 0;
+ return -EOPNOTSUPP;
}

void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus,
--
1.6.2.2