From: "Jason J. Herne" <jjherne@xxxxxxxxxxxxxxxxxx>
Provide the KVM_S390_GET_SKEYS and KVM_S390_SET_SKEYS ioctl which can be used
to get/set guest storage keys. This functionality is needed for live migration
of s390 guests that use storage keys.
Signed-off-by: Jason J. Herne <jjherne@xxxxxxxxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
Documentation/virtual/kvm/api.txt | 58 ++++++++++++++++++
arch/s390/kvm/kvm-s390.c | 122 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/kvm.h | 14 +++++
3 files changed, 194 insertions(+)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 74d18b6..589b9ac 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2762,6 +2762,64 @@ register number to be used.
The "reserved" field is meant for future extensions. It is not used by
KVM with the currently defined set of flags.
+4.90 KVM_S390_GET_SKEYS
+
+Capability: KVM_CAP_S390_SKEYS
+Architectures: s390
+Type: vm ioctl
+Parameters: struct kvm_s390_skeys
+Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage
+ keys, negative value on error
+
+This ioctl is used to get guest storage key values on the s390
+architecture. The ioctl takes parameters via the kvm_s390_skeys struct.
+
+struct kvm_s390_skeys {
+ __u64 start_gfn;
+ __u64 count;
+ __u64 skeydata_addr;
+ __u32 flags;
+ __u32 reserved[9];
+};
+
+The start_gfn field is the number of the first guest frame whose storage keys
+you want to get.
+
+The count field is the number of consecutive frames (starting from start_gfn)
+whose storage keys to get. The count field must be at least 1 and the maximum
+allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
+will cause the ioctl to return -EINVAL.
+
+The skeydata_addr field is the address to a buffer large enough to hold count
+bytes. This buffer will be filled with storage key data by the ioctl.
+
+4.91 KVM_S390_SET_SKEYS
+
+Capability: KVM_CAP_S390_SKEYS
+Architectures: s390
+Type: vm ioctl
+Parameters: struct kvm_s390_skeys
+Returns: 0 on success, negative value on error
+
+This ioctl is used to set guest storage key values on the s390
+architecture. The ioctl takes parameters via the kvm_s390_skeys struct.
+See section on KVM_S390_GET_SKEYS for struct definition.
+
+The start_gfn field is the number of the first guest frame whose storage keys
+you want to set.
+
+The count field is the number of consecutive frames (starting from start_gfn)
+whose storage keys to get. The count field must be at least 1 and the maximum
+allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
+will cause the ioctl to return -EINVAL.
+
+The skeydata_addr field is the address to a buffer containing count bytes of
+storage keys. Each byte in the buffer will be set as the storage key for a
+single frame starting at start_gfn for count frames.
+
+Note: If any architecturally invalid key value is found in the given data then
+the ioctl will return -EINVAL.
+
5. The kvm_run structure
------------------------
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index fdfa106..16d33f0 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -729,6 +729,108 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
return ret;
}
+static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
+{
+ uint8_t *keys;
+ uint64_t hva;
+ unsigned long curkey;
+ int i, r = 0;
+
+ if (args->flags != 0)
+ return -EINVAL;
+
+ /* Is this guest using storage keys? */
+ if (!mm_use_skey(current->mm))
+ return KVM_S390_GET_SKEYS_NONE;
+
+ /* Enforce sane limit on memory allocation */
+ if (args->count < 1 || args->count > KVM_S390_SKEYS_MAX)
+ return -EINVAL;
+
+ keys = kmalloc_array(args->count, sizeof(uint8_t),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!keys)
+ keys = vmalloc(sizeof(uint8_t) * args->count);
+ if (!keys)
+ return -ENOMEM;
+
+ for (i = 0; i < args->count; i++) {
+ hva = gfn_to_hva(kvm, args->start_gfn + i);
+ if (kvm_is_error_hva(hva)) {
+ r = -EFAULT;
+ goto out;
+ }
+
+ curkey = get_guest_storage_key(current->mm, hva);
+ if (IS_ERR_VALUE(curkey)) {
+ r = curkey;
+ goto out;
+ }
+ keys[i] = curkey;
+ }
+
+ r = copy_to_user((uint8_t __user *)args->skeydata_addr, keys,
+ sizeof(uint8_t) * args->count);
+ if (r)
+ r = -EFAULT;
+out:
+ kvfree(keys);
+ return r;
+}
+
+static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
+{
+ uint8_t *keys;
+ uint64_t hva;
+ int i, r = 0;
+
+ if (args->flags != 0)
+ return -EINVAL;
+
+ /* Enforce sane limit on memory allocation */
+ if (args->count < 1 || args->count > KVM_S390_SKEYS_MAX)
+ return -EINVAL;
+
+ keys = kmalloc_array(args->count, sizeof(uint8_t),
+ GFP_KERNEL | __GFP_NOWARN);
+ if (!keys)
+ keys = vmalloc(sizeof(uint8_t) * args->count);
+ if (!keys)
+ return -ENOMEM;
+
+ r = copy_from_user(keys, (uint8_t __user *)args->skeydata_addr,
+ sizeof(uint8_t) * args->count);
+ if (r) {
+ r = -EFAULT;
+ goto out;
+ }
+
+ /* Enable storage key handling for the guest */
+ s390_enable_skey();
+
+ for (i = 0; i < args->count; i++) {
+ hva = gfn_to_hva(kvm, args->start_gfn + i);
+ if (kvm_is_error_hva(hva)) {
+ r = -EFAULT;
+ goto out;
+ }
+
+ /* Lowest order bit is reserved */
+ if (keys[i] & 0x01) {
+ r = -EINVAL;
+ goto out;
+ }
+
+ r = set_guest_storage_key(current->mm, hva,
+ (unsigned long)keys[i], 0);
+ if (r)
+ goto out;
+ }
+out:
+ kvfree(keys);
+ return r;
+}
+
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -788,6 +890,26 @@ long kvm_arch_vm_ioctl(struct file *filp,
r = kvm_s390_vm_has_attr(kvm, &attr);
break;
}
+ case KVM_S390_GET_SKEYS: {
+ struct kvm_s390_skeys args;
+
+ r = -EFAULT;
+ if (copy_from_user(&args, argp,
+ sizeof(struct kvm_s390_skeys)))
+ break;
+ r = kvm_s390_get_skeys(kvm, &args);
+ break;
+ }
+ case KVM_S390_SET_SKEYS: {
+ struct kvm_s390_skeys args;
+
+ r = -EFAULT;
+ if (copy_from_user(&args, argp,
+ sizeof(struct kvm_s390_skeys)))
+ break;
+ r = kvm_s390_set_skeys(kvm, &args);
+ break;
+ }
default:
r = -ENOTTY;
}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 279ffd2..55dfd4c 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -147,6 +147,16 @@ struct kvm_pit_config {
#define KVM_PIT_SPEAKER_DUMMY 1
+struct kvm_s390_skeys {
+ __u64 start_gfn;
+ __u64 count;
+ __u64 skeydata_addr;
+ __u32 flags;
+ __u32 reserved[9];
+};
+#define KVM_S390_GET_SKEYS_NONE 1
+#define KVM_S390_SKEYS_MAX 1048576
+
#define KVM_EXIT_UNKNOWN 0
#define KVM_EXIT_EXCEPTION 1
#define KVM_EXIT_IO 2
@@ -791,6 +801,7 @@ struct kvm_ppc_smmu_info {
#define KVM_CAP_S390_VECTOR_REGISTERS 107
#define KVM_CAP_S390_MEM_OP 108
#define KVM_CAP_S390_USER_STSI 109
+#define KVM_CAP_S390_SKEYS 110
#ifdef KVM_CAP_IRQ_ROUTING
@@ -1168,6 +1179,9 @@ struct kvm_s390_ucas_mapping {
#define KVM_GET_REG_LIST _IOWR(KVMIO, 0xb0, struct kvm_reg_list)
/* Available with KVM_CAP_S390_MEM_OP */
#define KVM_S390_MEM_OP _IOW(KVMIO, 0xb1, struct kvm_s390_mem_op)
+/* Available with KVM_CAP_S390_SKEYS */
+#define KVM_S390_GET_SKEYS _IOW(KVMIO, 0xb2, struct kvm_s390_skeys)
+#define KVM_S390_SET_SKEYS _IOW(KVMIO, 0xb3, struct kvm_s390_skeys)
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
#define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1)
--
2.3.0
--
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