From: Will Deacon <will@kernel.org>
Date: Tue, 31 Mar 2026 15:50:55 +0000 (+0100)
Subject: KVM: arm64: Don't hold 'vm_table_lock' across guest page reclaim
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=bc20692f528b2ac8226bafe5b1db9a1f8be96dbf;p=thirdparty%2Fkernel%2Flinux.git

KVM: arm64: Don't hold 'vm_table_lock' across guest page reclaim

Now that the teardown of a VM cannot be finalised as long as a reference
is held on the VM, rework __pkvm_reclaim_dying_guest_page() to hold a
reference to the dying VM rather than take the global 'vm_table_lock'
during the reclaim operation.

Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260331155056.28220-4-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
---

diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c
index b955da0e50bc..7ed96d64d611 100644
--- a/arch/arm64/kvm/hyp/nvhe/pkvm.c
+++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c
@@ -918,15 +918,16 @@ teardown_donated_memory(struct kvm_hyp_memcache *mc, void *addr, size_t size)
 
 int __pkvm_reclaim_dying_guest_page(pkvm_handle_t handle, u64 gfn)
 {
-	struct pkvm_hyp_vm *hyp_vm;
+	struct pkvm_hyp_vm *hyp_vm = get_pkvm_hyp_vm(handle);
 	int ret = -EINVAL;
 
-	hyp_spin_lock(&vm_table_lock);
-	hyp_vm = get_vm_by_handle(handle);
-	if (hyp_vm && hyp_vm->kvm.arch.pkvm.is_dying)
+	if (!hyp_vm)
+		return ret;
+
+	if (hyp_vm->kvm.arch.pkvm.is_dying)
 		ret = __pkvm_host_reclaim_page_guest(gfn, hyp_vm);
-	hyp_spin_unlock(&vm_table_lock);
 
+	put_pkvm_hyp_vm(hyp_vm);
 	return ret;
 }