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/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7ce6367..96f0ae7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2333,35 +2333,23 @@
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 @@
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 @@
/*
* 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 @@
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 @@
/*
* 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 @@
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 @@
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 @@
{
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 @@
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 @@
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;
}
