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-rw-r--r--arch/arm64/include/asm/kvm_host.h3
-rw-r--r--arch/arm64/include/asm/mte-def.h1
-rw-r--r--arch/arm64/include/uapi/asm/kvm.h11
-rw-r--r--arch/arm64/kvm/arm.c7
-rw-r--r--arch/arm64/kvm/guest.c82
5 files changed, 104 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 74a7447a83a1..c93a7198c242 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -730,6 +730,9 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
+long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
+ struct kvm_arm_copy_mte_tags *copy_tags);
+
/* Guest/host FPSIMD coordination helpers */
int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/include/asm/mte-def.h b/arch/arm64/include/asm/mte-def.h
index cf241b0f0a42..626d359b396e 100644
--- a/arch/arm64/include/asm/mte-def.h
+++ b/arch/arm64/include/asm/mte-def.h
@@ -7,6 +7,7 @@
#define MTE_GRANULE_SIZE UL(16)
#define MTE_GRANULE_MASK (~(MTE_GRANULE_SIZE - 1))
+#define MTE_GRANULES_PER_PAGE (PAGE_SIZE / MTE_GRANULE_SIZE)
#define MTE_TAG_SHIFT 56
#define MTE_TAG_SIZE 4
#define MTE_TAG_MASK GENMASK((MTE_TAG_SHIFT + (MTE_TAG_SIZE - 1)), MTE_TAG_SHIFT)
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 24223adae150..b3edde68bc3e 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -184,6 +184,17 @@ struct kvm_vcpu_events {
__u32 reserved[12];
};
+struct kvm_arm_copy_mte_tags {
+ __u64 guest_ipa;
+ __u64 length;
+ void __user *addr;
+ __u64 flags;
+ __u64 reserved[2];
+};
+
+#define KVM_ARM_TAGS_TO_GUEST 0
+#define KVM_ARM_TAGS_FROM_GUEST 1
+
/* If you need to interpret the index values, here is the key: */
#define KVM_REG_ARM_COPROC_MASK 0x000000000FFF0000
#define KVM_REG_ARM_COPROC_SHIFT 16
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 28ce26a68f09..511f3716fe33 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1359,6 +1359,13 @@ long kvm_arch_vm_ioctl(struct file *filp,
return 0;
}
+ case KVM_ARM_MTE_COPY_TAGS: {
+ struct kvm_arm_copy_mte_tags copy_tags;
+
+ if (copy_from_user(&copy_tags, argp, sizeof(copy_tags)))
+ return -EFAULT;
+ return kvm_vm_ioctl_mte_copy_tags(kvm, &copy_tags);
+ }
default:
return -EINVAL;
}
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 5cb4a1cd5603..4ddb20017b2f 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -995,3 +995,85 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
return ret;
}
+
+long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
+ struct kvm_arm_copy_mte_tags *copy_tags)
+{
+ gpa_t guest_ipa = copy_tags->guest_ipa;
+ size_t length = copy_tags->length;
+ void __user *tags = copy_tags->addr;
+ gpa_t gfn;
+ bool write = !(copy_tags->flags & KVM_ARM_TAGS_FROM_GUEST);
+ int ret = 0;
+
+ if (!kvm_has_mte(kvm))
+ return -EINVAL;
+
+ if (copy_tags->reserved[0] || copy_tags->reserved[1])
+ return -EINVAL;
+
+ if (copy_tags->flags & ~KVM_ARM_TAGS_FROM_GUEST)
+ return -EINVAL;
+
+ if (length & ~PAGE_MASK || guest_ipa & ~PAGE_MASK)
+ return -EINVAL;
+
+ gfn = gpa_to_gfn(guest_ipa);
+
+ mutex_lock(&kvm->slots_lock);
+
+ while (length > 0) {
+ kvm_pfn_t pfn = gfn_to_pfn_prot(kvm, gfn, write, NULL);
+ void *maddr;
+ unsigned long num_tags;
+ struct page *page;
+
+ if (is_error_noslot_pfn(pfn)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ page = pfn_to_online_page(pfn);
+ if (!page) {
+ /* Reject ZONE_DEVICE memory */
+ ret = -EFAULT;
+ goto out;
+ }
+ maddr = page_address(page);
+
+ if (!write) {
+ if (test_bit(PG_mte_tagged, &page->flags))
+ num_tags = mte_copy_tags_to_user(tags, maddr,
+ MTE_GRANULES_PER_PAGE);
+ else
+ /* No tags in memory, so write zeros */
+ num_tags = MTE_GRANULES_PER_PAGE -
+ clear_user(tags, MTE_GRANULES_PER_PAGE);
+ kvm_release_pfn_clean(pfn);
+ } else {
+ num_tags = mte_copy_tags_from_user(maddr, tags,
+ MTE_GRANULES_PER_PAGE);
+ kvm_release_pfn_dirty(pfn);
+ }
+
+ if (num_tags != MTE_GRANULES_PER_PAGE) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ /* Set the flag after checking the write completed fully */
+ if (write)
+ set_bit(PG_mte_tagged, &page->flags);
+
+ gfn++;
+ tags += num_tags;
+ length -= PAGE_SIZE;
+ }
+
+out:
+ mutex_unlock(&kvm->slots_lock);
+ /* If some data has been copied report the number of bytes copied */
+ if (length != copy_tags->length)
+ return copy_tags->length - length;
+ return ret;
+}