Merge branch kvm-arm64/mmu-misc-6.12 into kvmarm-master/next

* kvm-arm64/mmu-misc-6.12:
  : .
  : Various minor MMU improvements and bug-fixes:
  :
  : - Prevent MTE tags being restored by userspace if we are actively
  :   logging writes, as that's a recipe for disaster
  :
  : - Correct the refcount on a page that is not considered for MTE
  :   tag copying (such as a device)
  :
  : - When walking a page table to split blocks, keep the DSB at the end
  :   the walk, as there is no need to perform it on every store.
  :
  : - Fix boundary check when transfering memory using FFA
  : .
  KVM: arm64: Add memory length checks and remove inline in do_ffa_mem_xfer
  KVM: arm64: Disallow copying MTE to guest memory while KVM is dirty logging
  KVM: arm64: Release pfn, i.e. put page, if copying MTE tags hits ZONE_DEVICE
  KVM: arm64: Move data barrier to end of split walk

Signed-off-by: Marc Zyngier <maz@kernel.org>

3 files changed, 25 insertions, 8 deletions

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 11098eb7eb44..962f985977c2 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -1045,6 +1045,11 @@ int kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
 
 	mutex_lock(&kvm->slots_lock);
 
+	if (write && atomic_read(&kvm->nr_memslots_dirty_logging)) {
+		ret = -EBUSY;
+		goto out;
+	}
+
 	while (length > 0) {
 		kvm_pfn_t pfn = gfn_to_pfn_prot(kvm, gfn, write, NULL);
 		void *maddr;
@@ -1059,6 +1064,7 @@ int kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,
 		page = pfn_to_online_page(pfn);
 		if (!page) {
 			/* Reject ZONE_DEVICE memory */
+			kvm_release_pfn_clean(pfn);
 			ret = -EFAULT;
 			goto out;
 		}
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index e715c157c2c4..e433dfab882a 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -426,9 +426,9 @@ out:
 	return;
 }
 
-static __always_inline void do_ffa_mem_xfer(const u64 func_id,
-					    struct arm_smccc_res *res,
-					    struct kvm_cpu_context *ctxt)
+static void __do_ffa_mem_xfer(const u64 func_id,
+			      struct arm_smccc_res *res,
+			      struct kvm_cpu_context *ctxt)
 {
 	DECLARE_REG(u32, len, ctxt, 1);
 	DECLARE_REG(u32, fraglen, ctxt, 2);
@@ -440,9 +440,6 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id,
 	u32 offset, nr_ranges;
 	int ret = 0;
 
-	BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE &&
-		     func_id != FFA_FN64_MEM_LEND);
-
 	if (addr_mbz || npages_mbz || fraglen > len ||
 	    fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) {
 		ret = FFA_RET_INVALID_PARAMETERS;
@@ -461,6 +458,11 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id,
 		goto out_unlock;
 	}
 
+	if (len > ffa_desc_buf.len) {
+		ret = FFA_RET_NO_MEMORY;
+		goto out_unlock;
+	}
+
 	buf = hyp_buffers.tx;
 	memcpy(buf, host_buffers.tx, fraglen);
 
@@ -512,6 +514,13 @@ err_unshare:
 	goto out_unlock;
 }
 
+#define do_ffa_mem_xfer(fid, res, ctxt)				\
+	do {							\
+		BUILD_BUG_ON((fid) != FFA_FN64_MEM_SHARE &&	\
+			     (fid) != FFA_FN64_MEM_LEND);	\
+		__do_ffa_mem_xfer((fid), (res), (ctxt));	\
+	} while (0);
+
 static void do_ffa_mem_reclaim(struct arm_smccc_res *res,
 			       struct kvm_cpu_context *ctxt)
 {
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 9e2bbee77491..9788af2ca8c0 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -1547,7 +1547,6 @@ static int stage2_split_walker(const struct kvm_pgtable_visit_ctx *ctx,
 	 */
 	new = kvm_init_table_pte(childp, mm_ops);
 	stage2_make_pte(ctx, new);
-	dsb(ishst);
 	return 0;
 }
 
@@ -1559,8 +1558,11 @@ int kvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size,
 		.flags	= KVM_PGTABLE_WALK_LEAF,
 		.arg	= mc,
 	};
+	int ret;
 
-	return kvm_pgtable_walk(pgt, addr, size, &walker);
+	ret = kvm_pgtable_walk(pgt, addr, size, &walker);
+	dsb(ishst);
+	return ret;
 }
 
 int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,