[PULL 050/102] i386/kvm: unregister smram listeners prior to vm file descriptor change

Paolo Bonzini posted 102 patches 1 month, 1 week ago
Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Alexander Graf <graf@amazon.com>, Pedro Barbuda <pbarbuda@microsoft.com>, Mohamed Mediouni <mohamed@unpredictable.fr>, Gerd Hoffmann <kraxel@redhat.com>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Pierrick Bouvier <pierrick.bouvier@linaro.org>, Dorjoy Chowdhury <dorjoychy111@gmail.com>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Zhao Liu <zhao1.liu@intel.com>, "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>, "Michael S. Tsirkin" <mst@redhat.com>, Richard Henderson <richard.henderson@linaro.org>, Bernhard Beschow <shentey@gmail.com>, Alex Williamson <alex@shazbot.org>, "Cédric Le Goater" <clg@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Peter Xu <peterx@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, John Snow <jsnow@redhat.com>, Cleber Rosa <crosa@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Manos Pitsidianakis <manos.pitsidianakis@linaro.org>, "Alex Bennée" <alex.bennee@linaro.org>, Thomas Huth <thuth@redhat.com>, Ani Sinha <anisinha@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Cameron Esfahani <dirty@apple.com>, Roman Bolshakov <rbolshakov@ddn.com>, Phil Dennis-Jordan <phil@philjordan.eu>, Wei Liu <wei.liu@kernel.org>, Marcelo Tosatti <mtosatti@redhat.com>, David Woodhouse <dwmw2@infradead.org>, Paul Durrant <paul@xen.org>, Magnus Kulke <magnus.kulke@linux.microsoft.com>, Fabiano Rosas <farosas@suse.de>, Laurent Vivier <lvivier@redhat.com>
[PULL 050/102] i386/kvm: unregister smram listeners prior to vm file descriptor change
Posted by Paolo Bonzini 1 month, 1 week ago
From: Ani Sinha <anisinha@redhat.com>

We will re-register smram listeners after the VM file descriptors has changed.
We need to unregister them first to make sure addresses and reference counters
work properly.

Signed-off-by: Ani Sinha <anisinha@redhat.com>
Link: https://lore.kernel.org/r/20260225035000.385950-10-anisinha@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/kvm/kvm.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 524b5276a68..8edfbb834c6 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -112,6 +112,11 @@ typedef struct {
 static void kvm_init_msrs(X86CPU *cpu);
 static int kvm_filter_msr(KVMState *s, uint32_t msr, QEMURDMSRHandler *rdmsr,
                           QEMUWRMSRHandler *wrmsr);
+static int unregister_smram_listener(NotifierWithReturn *notifier,
+                                     void *data, Error** errp);
+NotifierWithReturn kvm_vmfd_change_notifier = {
+    .notify = unregister_smram_listener,
+};
 
 const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
     KVM_CAP_INFO(SET_TSS_ADDR),
@@ -2885,6 +2890,17 @@ static void register_smram_listener(Notifier *n, void *unused)
     }
 }
 
+static int unregister_smram_listener(NotifierWithReturn *notifier,
+                                     void *data, Error** errp)
+{
+    if (!((VmfdChangeNotifier *)data)->pre) {
+        return 0;
+    }
+
+    memory_listener_unregister(&smram_listener.listener);
+    return 0;
+}
+
 /* It should only be called in cpu's hotplug callback */
 void kvm_smm_cpu_address_space_init(X86CPU *cpu)
 {
@@ -3538,6 +3554,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
     }
 
     pmu_cap = kvm_check_extension(s, KVM_CAP_PMU_CAPABILITY);
+    kvm_vmfd_add_change_notifier(&kvm_vmfd_change_notifier);
 
     return 0;
 }
-- 
2.53.0