KVM: remove in_range from io devices

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>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 5c766bd..d7aa6bb 100644 (file)
--- 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 4082cdd..8c3ac30 100644 (file)
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -358,8 +358,14 @@ 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;
@@ -367,6 +373,8 @@ 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;
@@ -429,16 +437,19 @@ 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];
@@ -493,37 +504,36 @@ 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;
@@ -535,12 +545,7 @@ 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)
@@ -574,13 +579,11 @@ 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 (file)
--- 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 (file)
--- 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 7ce6367..96f0ae7 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2333,35 +2333,23 @@ 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,
@@ -2430,7 +2418,6 @@ 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) {
@@ -2455,13 +2442,8 @@ 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;
@@ -2488,7 +2470,6 @@ 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);
@@ -2509,13 +2490,8 @@ 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;
@@ -2850,48 +2826,40 @@ 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;
@@ -2911,11 +2879,7 @@ 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;
        }
@@ -2929,7 +2893,6 @@ 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;
@@ -2973,12 +2936,6 @@ 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);
@@ -2986,16 +2943,13 @@ 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 96c8c0b..077e8bb 100644 (file)
--- 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 (file)
--- 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 0eca54e..ddf6aa9 100644 (file)
--- 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 (file)
--- 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 0edc366..5946065 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2512,19 +2512,25 @@ 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,