diff --git a/include/linux/kvm.h b/include/linux/kvm.h index a281afeddfb..1c908ac29c6 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -173,6 +173,30 @@ struct kvm_run { }; }; +/* for KVM_REGISTER_COALESCED_MMIO / KVM_UNREGISTER_COALESCED_MMIO */ + +struct kvm_coalesced_mmio_zone { + __u64 addr; + __u32 size; + __u32 pad; +}; + +struct kvm_coalesced_mmio { + __u64 phys_addr; + __u32 len; + __u32 pad; + __u8 data[8]; +}; + +struct kvm_coalesced_mmio_ring { + __u32 first, last; + struct kvm_coalesced_mmio coalesced_mmio[0]; +}; + +#define KVM_COALESCED_MMIO_MAX \ + ((PAGE_SIZE - sizeof(struct kvm_coalesced_mmio_ring)) / \ + sizeof(struct kvm_coalesced_mmio)) + /* for KVM_TRANSLATE */ struct kvm_translation { /* in */ @@ -346,6 +370,7 @@ struct kvm_trace_rec { #define KVM_CAP_NOP_IO_DELAY 12 #define KVM_CAP_PV_MMU 13 #define KVM_CAP_MP_STATE 14 +#define KVM_CAP_COALESCED_MMIO 15 /* * ioctls for VM fds @@ -371,6 +396,10 @@ struct kvm_trace_rec { #define KVM_CREATE_PIT _IO(KVMIO, 0x64) #define KVM_GET_PIT _IOWR(KVMIO, 0x65, struct kvm_pit_state) #define KVM_SET_PIT _IOR(KVMIO, 0x66, struct kvm_pit_state) +#define KVM_REGISTER_COALESCED_MMIO \ + _IOW(KVMIO, 0x67, struct kvm_coalesced_mmio_zone) +#define KVM_UNREGISTER_COALESCED_MMIO \ + _IOW(KVMIO, 0x68, struct kvm_coalesced_mmio_zone) /* * ioctls for vcpu fds diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 499ff060423..d220b4926c4 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -117,6 +117,10 @@ struct kvm { struct kvm_vm_stat stat; struct kvm_arch arch; atomic_t users_count; +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET + struct kvm_coalesced_mmio_dev *coalesced_mmio_dev; + struct kvm_coalesced_mmio_ring *coalesced_mmio_ring; +#endif }; /* The guest did something we don't support. */ diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c new file mode 100644 index 00000000000..5ae620d32fa --- /dev/null +++ b/virt/kvm/coalesced_mmio.c @@ -0,0 +1,156 @@ +/* + * KVM coalesced MMIO + * + * Copyright (c) 2008 Bull S.A.S. + * + * Author: Laurent Vivier + * + */ + +#include "iodev.h" + +#include +#include + +#include "coalesced_mmio.h" + +static int coalesced_mmio_in_range(struct kvm_io_device *this, + gpa_t addr, int len, int is_write) +{ + struct kvm_coalesced_mmio_dev *dev = + (struct kvm_coalesced_mmio_dev*)this->private; + struct kvm_coalesced_mmio_zone *zone; + int next; + int i; + + if (!is_write) + return 0; + + /* kvm->lock is taken by the caller and must be not released before + * dev.read/write + */ + + /* Are we able to batch it ? */ + + /* last is the first free entry + * check if we don't meet the first used entry + * there is always one unused entry in the buffer + */ + + next = (dev->kvm->coalesced_mmio_ring->last + 1) % + KVM_COALESCED_MMIO_MAX; + if (next == dev->kvm->coalesced_mmio_ring->first) { + /* full */ + return 0; + } + + /* is it in a batchable area ? */ + + for (i = 0; i < dev->nb_zones; i++) { + zone = &dev->zone[i]; + + /* (addr,len) is fully included in + * (zone->addr, zone->size) + */ + + if (zone->addr <= addr && + addr + len <= zone->addr + zone->size) + return 1; + } + return 0; +} + +static void coalesced_mmio_write(struct kvm_io_device *this, + gpa_t addr, int len, const void *val) +{ + struct kvm_coalesced_mmio_dev *dev = + (struct kvm_coalesced_mmio_dev*)this->private; + struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring; + + /* kvm->lock must be taken by caller before call to in_range()*/ + + /* copy data in first free entry of the ring */ + + ring->coalesced_mmio[ring->last].phys_addr = addr; + ring->coalesced_mmio[ring->last].len = len; + memcpy(ring->coalesced_mmio[ring->last].data, val, len); + smp_wmb(); + ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX; +} + +static void coalesced_mmio_destructor(struct kvm_io_device *this) +{ + kfree(this); +} + +int kvm_coalesced_mmio_init(struct kvm *kvm) +{ + struct kvm_coalesced_mmio_dev *dev; + + dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + dev->dev.write = coalesced_mmio_write; + dev->dev.in_range = coalesced_mmio_in_range; + dev->dev.destructor = coalesced_mmio_destructor; + dev->dev.private = dev; + dev->kvm = kvm; + kvm->coalesced_mmio_dev = dev; + kvm_io_bus_register_dev(&kvm->mmio_bus, &dev->dev); + + return 0; +} + +int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, + struct kvm_coalesced_mmio_zone *zone) +{ + struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; + + if (dev == NULL) + return -EINVAL; + + mutex_lock(&kvm->lock); + if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) { + mutex_unlock(&kvm->lock); + return -ENOBUFS; + } + + dev->zone[dev->nb_zones] = *zone; + dev->nb_zones++; + + mutex_unlock(&kvm->lock); + return 0; +} + +int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, + struct kvm_coalesced_mmio_zone *zone) +{ + int i; + struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev; + struct kvm_coalesced_mmio_zone *z; + + if (dev == NULL) + return -EINVAL; + + mutex_lock(&kvm->lock); + + i = dev->nb_zones; + while(i) { + z = &dev->zone[i - 1]; + + /* unregister all zones + * included in (zone->addr, zone->size) + */ + + if (zone->addr <= z->addr && + z->addr + z->size <= zone->addr + zone->size) { + dev->nb_zones--; + *z = dev->zone[dev->nb_zones]; + } + i--; + } + + mutex_unlock(&kvm->lock); + + return 0; +} diff --git a/virt/kvm/coalesced_mmio.h b/virt/kvm/coalesced_mmio.h new file mode 100644 index 00000000000..5ac0ec62846 --- /dev/null +++ b/virt/kvm/coalesced_mmio.h @@ -0,0 +1,23 @@ +/* + * KVM coalesced MMIO + * + * Copyright (c) 2008 Bull S.A.S. + * + * Author: Laurent Vivier + * + */ + +#define KVM_COALESCED_MMIO_ZONE_MAX 100 + +struct kvm_coalesced_mmio_dev { + struct kvm_io_device dev; + struct kvm *kvm; + int nb_zones; + struct kvm_coalesced_mmio_zone zone[KVM_COALESCED_MMIO_ZONE_MAX]; +}; + +int kvm_coalesced_mmio_init(struct kvm *kvm); +int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm, + struct kvm_coalesced_mmio_zone *zone); +int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm, + struct kvm_coalesced_mmio_zone *zone); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 9330fad2b91..7d10dfa0d38 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -47,6 +47,10 @@ #include #include +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET +#include "coalesced_mmio.h" +#endif + MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); @@ -185,10 +189,23 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_uninit); static struct kvm *kvm_create_vm(void) { struct kvm *kvm = kvm_arch_create_vm(); +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET + struct page *page; +#endif if (IS_ERR(kvm)) goto out; +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET + page = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!page) { + kfree(kvm); + return ERR_PTR(-ENOMEM); + } + kvm->coalesced_mmio_ring = + (struct kvm_coalesced_mmio_ring *)page_address(page); +#endif + kvm->mm = current->mm; atomic_inc(&kvm->mm->mm_count); spin_lock_init(&kvm->mmu_lock); @@ -200,6 +217,9 @@ static struct kvm *kvm_create_vm(void) spin_lock(&kvm_lock); list_add(&kvm->vm_list, &vm_list); spin_unlock(&kvm_lock); +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET + kvm_coalesced_mmio_init(kvm); +#endif out: return kvm; } @@ -242,6 +262,10 @@ static void kvm_destroy_vm(struct kvm *kvm) spin_unlock(&kvm_lock); kvm_io_bus_destroy(&kvm->pio_bus); kvm_io_bus_destroy(&kvm->mmio_bus); +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET + if (kvm->coalesced_mmio_ring != NULL) + free_page((unsigned long)kvm->coalesced_mmio_ring); +#endif kvm_arch_destroy_vm(kvm); mmdrop(mm); } @@ -825,6 +849,10 @@ static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf) #ifdef CONFIG_X86 else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET) page = virt_to_page(vcpu->arch.pio_data); +#endif +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET + else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET) + page = virt_to_page(vcpu->kvm->coalesced_mmio_ring); #endif else return VM_FAULT_SIGBUS; @@ -1148,6 +1176,32 @@ static long kvm_vm_ioctl(struct file *filp, goto out; break; } +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET + case KVM_REGISTER_COALESCED_MMIO: { + struct kvm_coalesced_mmio_zone zone; + r = -EFAULT; + if (copy_from_user(&zone, argp, sizeof zone)) + goto out; + r = -ENXIO; + r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone); + if (r) + goto out; + r = 0; + break; + } + case KVM_UNREGISTER_COALESCED_MMIO: { + struct kvm_coalesced_mmio_zone zone; + r = -EFAULT; + if (copy_from_user(&zone, argp, sizeof zone)) + goto out; + r = -ENXIO; + r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone); + if (r) + goto out; + r = 0; + break; + } +#endif default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); } @@ -1231,6 +1285,9 @@ static long kvm_dev_ioctl(struct file *filp, r = PAGE_SIZE; /* struct kvm_run */ #ifdef CONFIG_X86 r += PAGE_SIZE; /* pio data page */ +#endif +#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET + r += PAGE_SIZE; /* coalesced mmio ring page */ #endif break; case KVM_TRACE_ENABLE: