KVM: implement multiple address spaces
Only two ioctls have to be modified; the address space id is
placed in the higher 16 bits of their slot id argument.
As of this patch, no architecture defines more than one
address space; x86 will be the first.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 2ddefd5..461956a 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -254,6 +254,11 @@
memory slot. Ensure the entire structure is cleared to avoid padding
issues.
+If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 specifies
+the address space for which you want to return the dirty bitmap.
+They must be less than the value that KVM_CHECK_EXTENSION returns for
+the KVM_CAP_MULTI_ADDRESS_SPACE capability.
+
4.9 KVM_SET_MEMORY_ALIAS
@@ -924,6 +929,13 @@
physical memory space, or its flags may be modified. It may not be
resized. Slots may not overlap in guest physical address space.
+If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot"
+specifies the address space which is being modified. They must be
+less than the value that KVM_CHECK_EXTENSION returns for the
+KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces
+are unrelated; the restriction on overlapping slots only applies within
+each address space.
+
Memory for the region is taken starting at the address denoted by the
field userspace_addr, which must point at user addressable memory for
the entire memory slot size. Any object may back this memory, including
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 3536d12..2aa79c8 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -430,7 +430,7 @@
*/
static inline struct kvm_memslots *kvm_memslots_raw(struct kvm *kvm)
{
- return rcu_dereference_raw_notrace(kvm->memslots);
+ return rcu_dereference_raw_notrace(kvm->memslots[0]);
}
extern void kvmppc_mmu_debugfs_init(struct kvm *kvm);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ba1ea43..9564fd7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -44,6 +44,10 @@
/* Two fragments for cross MMIO pages. */
#define KVM_MAX_MMIO_FRAGMENTS 2
+#ifndef KVM_ADDRESS_SPACE_NUM
+#define KVM_ADDRESS_SPACE_NUM 1
+#endif
+
/*
* For the normal pfn, the highest 12 bits should be zero,
* so we can mask bit 62 ~ bit 52 to indicate the error pfn,
@@ -331,6 +335,13 @@
#define KVM_MEM_SLOTS_NUM (KVM_USER_MEM_SLOTS + KVM_PRIVATE_MEM_SLOTS)
#endif
+#ifndef __KVM_VCPU_MULTIPLE_ADDRESS_SPACE
+static inline int kvm_arch_vcpu_memslots_id(struct kvm_vcpu *vcpu)
+{
+ return 0;
+}
+#endif
+
/*
* Note:
* memslots are not sorted by id anymore, please use id_to_memslot()
@@ -349,7 +360,7 @@
spinlock_t mmu_lock;
struct mutex slots_lock;
struct mm_struct *mm; /* userspace tied to this vm */
- struct kvm_memslots *memslots;
+ struct kvm_memslots *memslots[KVM_ADDRESS_SPACE_NUM];
struct srcu_struct srcu;
struct srcu_struct irq_srcu;
#ifdef CONFIG_KVM_APIC_ARCHITECTURE
@@ -464,16 +475,23 @@
void kvm_get_kvm(struct kvm *kvm);
void kvm_put_kvm(struct kvm *kvm);
-static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)
+static inline struct kvm_memslots *__kvm_memslots(struct kvm *kvm, int as_id)
{
- return rcu_dereference_check(kvm->memslots,
+ return rcu_dereference_check(kvm->memslots[as_id],
srcu_read_lock_held(&kvm->srcu)
|| lockdep_is_held(&kvm->slots_lock));
}
+static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)
+{
+ return __kvm_memslots(kvm, 0);
+}
+
static inline struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu)
{
- return kvm_memslots(vcpu->kvm);
+ int as_id = kvm_arch_vcpu_memslots_id(vcpu);
+
+ return __kvm_memslots(vcpu->kvm, as_id);
}
static inline struct kvm_memory_slot *
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index eace8ba..5ff1038 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -816,6 +816,7 @@
#define KVM_CAP_PPC_HWRNG 115
#define KVM_CAP_DISABLE_QUIRKS 116
#define KVM_CAP_X86_SMM 117
+#define KVM_CAP_MULTI_ADDRESS_SPACE 118
#ifdef KVM_CAP_IRQ_ROUTING
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3a121ce..848af90 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -518,9 +518,11 @@
BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
r = -ENOMEM;
- kvm->memslots = kvm_alloc_memslots();
- if (!kvm->memslots)
- goto out_err_no_srcu;
+ for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+ kvm->memslots[i] = kvm_alloc_memslots();
+ if (!kvm->memslots[i])
+ goto out_err_no_srcu;
+ }
if (init_srcu_struct(&kvm->srcu))
goto out_err_no_srcu;
@@ -562,7 +564,8 @@
out_err_no_disable:
for (i = 0; i < KVM_NR_BUSES; i++)
kfree(kvm->buses[i]);
- kvm_free_memslots(kvm, kvm->memslots);
+ for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
+ kvm_free_memslots(kvm, kvm->memslots[i]);
kvm_arch_free_vm(kvm);
return ERR_PTR(r);
}
@@ -612,7 +615,8 @@
#endif
kvm_arch_destroy_vm(kvm);
kvm_destroy_devices(kvm);
- kvm_free_memslots(kvm, kvm->memslots);
+ for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
+ kvm_free_memslots(kvm, kvm->memslots[i]);
cleanup_srcu_struct(&kvm->irq_srcu);
cleanup_srcu_struct(&kvm->srcu);
kvm_arch_free_vm(kvm);
@@ -729,9 +733,9 @@
}
static struct kvm_memslots *install_new_memslots(struct kvm *kvm,
- struct kvm_memslots *slots)
+ int as_id, struct kvm_memslots *slots)
{
- struct kvm_memslots *old_memslots = kvm_memslots(kvm);
+ struct kvm_memslots *old_memslots = __kvm_memslots(kvm, as_id);
/*
* Set the low bit in the generation, which disables SPTE caching
@@ -740,7 +744,7 @@
WARN_ON(old_memslots->generation & 1);
slots->generation = old_memslots->generation + 1;
- rcu_assign_pointer(kvm->memslots, slots);
+ rcu_assign_pointer(kvm->memslots[as_id], slots);
synchronize_srcu_expedited(&kvm->srcu);
/*
@@ -772,6 +776,7 @@
struct kvm_memory_slot *slot;
struct kvm_memory_slot old, new;
struct kvm_memslots *slots = NULL, *old_memslots;
+ int as_id, id;
enum kvm_mr_change change;
r = check_memory_region_flags(mem);
@@ -779,24 +784,27 @@
goto out;
r = -EINVAL;
+ as_id = mem->slot >> 16;
+ id = (u16)mem->slot;
+
/* General sanity checks */
if (mem->memory_size & (PAGE_SIZE - 1))
goto out;
if (mem->guest_phys_addr & (PAGE_SIZE - 1))
goto out;
/* We can read the guest memory with __xxx_user() later on. */
- if ((mem->slot < KVM_USER_MEM_SLOTS) &&
+ if ((id < KVM_USER_MEM_SLOTS) &&
((mem->userspace_addr & (PAGE_SIZE - 1)) ||
!access_ok(VERIFY_WRITE,
(void __user *)(unsigned long)mem->userspace_addr,
mem->memory_size)))
goto out;
- if (mem->slot >= KVM_MEM_SLOTS_NUM)
+ if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
goto out;
if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
goto out;
- slot = id_to_memslot(kvm_memslots(kvm), mem->slot);
+ slot = id_to_memslot(__kvm_memslots(kvm, as_id), id);
base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
npages = mem->memory_size >> PAGE_SHIFT;
@@ -805,7 +813,7 @@
new = old = *slot;
- new.id = mem->slot;
+ new.id = id;
new.base_gfn = base_gfn;
new.npages = npages;
new.flags = mem->flags;
@@ -840,9 +848,9 @@
if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
/* Check for overlaps */
r = -EEXIST;
- kvm_for_each_memslot(slot, kvm_memslots(kvm)) {
+ kvm_for_each_memslot(slot, __kvm_memslots(kvm, as_id)) {
if ((slot->id >= KVM_USER_MEM_SLOTS) ||
- (slot->id == mem->slot))
+ (slot->id == id))
continue;
if (!((base_gfn + npages <= slot->base_gfn) ||
(base_gfn >= slot->base_gfn + slot->npages)))
@@ -871,13 +879,13 @@
slots = kvm_kvzalloc(sizeof(struct kvm_memslots));
if (!slots)
goto out_free;
- memcpy(slots, kvm_memslots(kvm), sizeof(struct kvm_memslots));
+ memcpy(slots, __kvm_memslots(kvm, as_id), sizeof(struct kvm_memslots));
if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) {
- slot = id_to_memslot(slots, mem->slot);
+ slot = id_to_memslot(slots, id);
slot->flags |= KVM_MEMSLOT_INVALID;
- old_memslots = install_new_memslots(kvm, slots);
+ old_memslots = install_new_memslots(kvm, as_id, slots);
/* slot was deleted or moved, clear iommu mapping */
kvm_iommu_unmap_pages(kvm, &old);
@@ -909,7 +917,7 @@
}
update_memslots(slots, &new);
- old_memslots = install_new_memslots(kvm, slots);
+ old_memslots = install_new_memslots(kvm, as_id, slots);
kvm_arch_commit_memory_region(kvm, mem, &old, &new, change);
@@ -956,7 +964,7 @@
static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem)
{
- if (mem->slot >= KVM_USER_MEM_SLOTS)
+ if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
return -EINVAL;
return kvm_set_memory_region(kvm, mem);
@@ -967,16 +975,18 @@
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
- int r, i;
+ int r, i, as_id, id;
unsigned long n;
unsigned long any = 0;
r = -EINVAL;
- if (log->slot >= KVM_USER_MEM_SLOTS)
+ as_id = log->slot >> 16;
+ id = (u16)log->slot;
+ if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
goto out;
- slots = kvm_memslots(kvm);
- memslot = id_to_memslot(slots, log->slot);
+ slots = __kvm_memslots(kvm, as_id);
+ memslot = id_to_memslot(slots, id);
r = -ENOENT;
if (!memslot->dirty_bitmap)
goto out;
@@ -1027,17 +1037,19 @@
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
- int r, i;
+ int r, i, as_id, id;
unsigned long n;
unsigned long *dirty_bitmap;
unsigned long *dirty_bitmap_buffer;
r = -EINVAL;
- if (log->slot >= KVM_USER_MEM_SLOTS)
+ as_id = log->slot >> 16;
+ id = (u16)log->slot;
+ if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
goto out;
- slots = kvm_memslots(kvm);
- memslot = id_to_memslot(slots, log->slot);
+ slots = __kvm_memslots(kvm, as_id);
+ memslot = id_to_memslot(slots, id);
dirty_bitmap = memslot->dirty_bitmap;
r = -ENOENT;
@@ -2620,6 +2632,10 @@
case KVM_CAP_IRQ_ROUTING:
return KVM_MAX_IRQ_ROUTES;
#endif
+#if KVM_ADDRESS_SPACE_NUM > 1
+ case KVM_CAP_MULTI_ADDRESS_SPACE:
+ return KVM_ADDRESS_SPACE_NUM;
+#endif
default:
break;
}