diff options
| -rw-r--r-- | drivers/kvm/kvm.h | 9 | ||||
| -rw-r--r-- | drivers/kvm/kvm_main.c | 89 | ||||
| -rw-r--r-- | include/linux/kvm.h | 10 |
3 files changed, 104 insertions, 4 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index d19985a5508..fceeb840a25 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -51,6 +51,7 @@ #define UNMAPPED_GVA (~(gpa_t)0) #define KVM_MAX_VCPUS 1 +#define KVM_ALIAS_SLOTS 4 #define KVM_MEMORY_SLOTS 4 #define KVM_NUM_MMU_PAGES 256 #define KVM_MIN_FREE_MMU_PAGES 5 @@ -312,6 +313,12 @@ struct kvm_vcpu { struct kvm_cpuid_entry cpuid_entries[KVM_MAX_CPUID_ENTRIES]; }; +struct kvm_mem_alias { + gfn_t base_gfn; + unsigned long npages; + gfn_t target_gfn; +}; + struct kvm_memory_slot { gfn_t base_gfn; unsigned long npages; @@ -322,6 +329,8 @@ struct kvm_memory_slot { struct kvm { spinlock_t lock; /* protects everything except vcpus */ + int naliases; + struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS]; int nmemslots; struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS]; /* diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index a0ec5dda330..e495855727e 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -846,7 +846,73 @@ out: return r; } -struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) +/* + * Set a new alias region. Aliases map a portion of physical memory into + * another portion. This is useful for memory windows, for example the PC + * VGA region. + */ +static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm, + struct kvm_memory_alias *alias) +{ + int r, n; + struct kvm_mem_alias *p; + + r = -EINVAL; + /* General sanity checks */ + if (alias->memory_size & (PAGE_SIZE - 1)) + goto out; + if (alias->guest_phys_addr & (PAGE_SIZE - 1)) + goto out; + if (alias->slot >= KVM_ALIAS_SLOTS) + goto out; + if (alias->guest_phys_addr + alias->memory_size + < alias->guest_phys_addr) + goto out; + if (alias->target_phys_addr + alias->memory_size + < alias->target_phys_addr) + goto out; + + spin_lock(&kvm->lock); + + p = &kvm->aliases[alias->slot]; + p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT; + p->npages = alias->memory_size >> PAGE_SHIFT; + p->target_gfn = alias->target_phys_addr >> PAGE_SHIFT; + + for (n = KVM_ALIAS_SLOTS; n > 0; --n) + if (kvm->aliases[n - 1].npages) + break; + kvm->naliases = n; + + spin_unlock(&kvm->lock); + + vcpu_load(&kvm->vcpus[0]); + spin_lock(&kvm->lock); + kvm_mmu_zap_all(&kvm->vcpus[0]); + spin_unlock(&kvm->lock); + vcpu_put(&kvm->vcpus[0]); + + return 0; + +out: + return r; +} + +static gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) +{ + int i; + struct kvm_mem_alias *alias; + + for (i = 0; i < kvm->naliases; ++i) { + alias = &kvm->aliases[i]; + if (gfn >= alias->base_gfn + && gfn < alias->base_gfn + alias->npages) + return alias->target_gfn + gfn - alias->base_gfn; + } + return gfn; +} + +static struct kvm_memory_slot *__gfn_to_memslot(struct kvm *kvm, gfn_t gfn) { int i; @@ -859,13 +925,19 @@ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) } return NULL; } -EXPORT_SYMBOL_GPL(gfn_to_memslot); + +struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) +{ + gfn = unalias_gfn(kvm, gfn); + return __gfn_to_memslot(kvm, gfn); +} struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *slot; - slot = gfn_to_memslot(kvm, gfn); + gfn = unalias_gfn(kvm, gfn); + slot = __gfn_to_memslot(kvm, gfn); if (!slot) return NULL; return slot->phys_mem[gfn - slot->base_gfn]; @@ -2512,6 +2584,17 @@ static long kvm_vm_ioctl(struct file *filp, goto out; break; } + case KVM_SET_MEMORY_ALIAS: { + struct kvm_memory_alias alias; + + r = -EFAULT; + if (copy_from_user(&alias, argp, sizeof alias)) + goto out; + r = kvm_vm_ioctl_set_memory_alias(kvm, &alias); + if (r) + goto out; + break; + } default: ; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 728b24cf5d7..da9b23fa4b6 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -11,7 +11,7 @@ #include <asm/types.h> #include <linux/ioctl.h> -#define KVM_API_VERSION 9 +#define KVM_API_VERSION 10 /* * Architectural interrupt line count, and the size of the bitmap needed @@ -33,6 +33,13 @@ struct kvm_memory_region { /* for kvm_memory_region::flags */ #define KVM_MEM_LOG_DIRTY_PAGES 1UL +struct kvm_memory_alias { + __u32 slot; /* this has a different namespace than memory slots */ + __u32 flags; + __u64 guest_phys_addr; + __u64 memory_size; + __u64 target_phys_addr; +}; enum kvm_exit_reason { KVM_EXIT_UNKNOWN = 0, @@ -261,6 +268,7 @@ struct kvm_signal_mask { */ #define KVM_CREATE_VCPU _IO(KVMIO, 0x41) #define KVM_GET_DIRTY_LOG _IOW(KVMIO, 0x42, struct kvm_dirty_log) +#define KVM_SET_MEMORY_ALIAS _IOW(KVMIO, 0x43, struct kvm_memory_alias) /* * ioctls for vcpu fds |