From 2eeb2e94eb6232f0895da696c10e6636093ff72b Mon Sep 17 00:00:00 2001 From: Gregory Haskins Date: Thu, 31 May 2007 14:08:53 -0400 Subject: [PATCH] KVM: Adds support for in-kernel mmio handlers Signed-off-by: Gregory Haskins Signed-off-by: Avi Kivity --- drivers/kvm/kvm.h | 60 +++++++++++++++++++++++++++ drivers/kvm/kvm_main.c | 94 ++++++++++++++++++++++++++++++++++++------ 2 files changed, 142 insertions(+), 12 deletions(-) diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index b08272bce213..31846b1c162f 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -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 { diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 633c2eded08d..e157e282fcff 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -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 */ -- 2.39.2