iommu/vt-d: Fix lock inversion between iommu->lock and device_domain_lock
Lockdep debug reported lock inversion related with the iommu code caused by dmar_insert_one_dev_info() grabbing the iommu->lock and the device_domain_lock out of order versus the code path in iommu_flush_dev_iotlb(). Expanding the scope of the iommu->lock and reversing the order of lock acquisition fixes the issue. [ 76.238180] dsa_bus wq0.0: dsa wq wq0.0 disabled [ 76.248706] [ 76.250486] ======================================================== [ 76.257113] WARNING: possible irq lock inversion dependency detected [ 76.263736] 5.1.0-rc5+ #162 Not tainted [ 76.267854] -------------------------------------------------------- [ 76.274485] systemd-journal/521 just changed the state of lock: [ 76.280685] 0000000055b330f5 (device_domain_lock){..-.}, at: iommu_flush_dev_iotlb.part.63+0x29/0x90 [ 76.290099] but this lock took another, SOFTIRQ-unsafe lock in the past: [ 76.297093] (&(&iommu->lock)->rlock){+.+.} [ 76.297094] [ 76.297094] [ 76.297094] and interrupts could create inverse lock ordering between them. [ 76.297094] [ 76.314257] [ 76.314257] other info that might help us debug this: [ 76.321448] Possible interrupt unsafe locking scenario: [ 76.321448] [ 76.328907] CPU0 CPU1 [ 76.333777] ---- ---- [ 76.338642] lock(&(&iommu->lock)->rlock); [ 76.343165] local_irq_disable(); [ 76.349422] lock(device_domain_lock); [ 76.356116] lock(&(&iommu->lock)->rlock); [ 76.363154] <Interrupt> [ 76.366134] lock(device_domain_lock); [ 76.370548] [ 76.370548] *** DEADLOCK *** Fixes: 745f2586 ("iommu/vt-d: Simplify function get_domain_for_dev()") Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
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