I haven't heard anything about this patch for a while.
https://patchew.org/QEMU/20240903062953.3926498-1-erbse.13@gmx.de/

From 5c1ad1ff44438402ec824a224ac4659c8044ec7e Mon Sep 17 00:00:00 2001
From: Tom Dohrmann <erbse.13@gmx.de>
Date: Tue, 3 Sep 2024 06:25:04 +0000
Subject: [PATCH] accel/kvm: check for KVM_CAP_READONLY_MEM on VM

KVM_CAP_READONLY_MEM used to be a global capability, but with the
introduction of AMD SEV-SNP confidential VMs, this extension is not
always available on all VM types [1,2].

Query the extension on the VM level instead of on the KVM level.

[1] https://patchwork.kernel.org/project/kvm/patch/20240809190319.1710470-2-seanjc@google.com/
[2] https://patchwork.kernel.org/project/kvm/patch/20240902144219.3716974-1-erbse.13@gmx.de/

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Tom Dohrmann <erbse.13@gmx.de>
---
 accel/kvm/kvm-all.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 75d11a07b2..acc23092e7 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2603,7 +2603,7 @@ static int kvm_init(MachineState *ms)
     }

     kvm_readonly_mem_allowed =
-        (kvm_check_extension(s, KVM_CAP_READONLY_MEM) > 0);
+        (kvm_vm_check_extension(s, KVM_CAP_READONLY_MEM) > 0);

     kvm_resamplefds_allowed =
         (kvm_check_extension(s, KVM_CAP_IRQFD_RESAMPLE) > 0);
--
2.34.1