/* * KVM coalesced MMIO * * Copyright (c) 2008 Bull S.A.S. * * Author: Laurent Vivier <Laurent.Vivier@bull.net> * */ #include "iodev.h" #include <linux/kvm_host.h> #include <linux/kvm.h> #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; }