From: Sean Christopherson Date: Sat, 15 Mar 2025 03:10:48 +0000 (-0700) Subject: iommu/amd: Ensure GA log notifier callbacks finish running before module unload X-Git-Tag: v6.16-rc1~110^2^11~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=94c721ea03c7078163f41dbaa101ac721ddac329;p=thirdparty%2Fkernel%2Flinux.git iommu/amd: Ensure GA log notifier callbacks finish running before module unload Synchronize RCU when unregistering KVM's GA log notifier to ensure all in-flight interrupt handlers complete before KVM-the module is unloaded. Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20250315031048.2374109-1-seanjc@google.com Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index be8761bbef0ff..15e3342648811 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -982,6 +982,14 @@ int amd_iommu_register_ga_log_notifier(int (*notifier)(u32)) { iommu_ga_log_notifier = notifier; + /* + * Ensure all in-flight IRQ handlers run to completion before returning + * to the caller, e.g. to ensure module code isn't unloaded while it's + * being executed in the IRQ handler. + */ + if (!notifier) + synchronize_rcu(); + return 0; } EXPORT_SYMBOL(amd_iommu_register_ga_log_notifier);