From 682edb4c01e690c7c7cd772dbd6f4e0fd74dc572 Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Thu, 5 Feb 2009 18:23:46 +0000 Subject: [PATCH] KVM: Fix assigned devices circular locking dependency kvm->slots_lock is outer to kvm->lock, so take slots_lock in kvm_vm_ioctl_assign_device() before taking kvm->lock, rather than taking it in kvm_iommu_map_memslots(). Cc: stable@kernel.org Signed-off-by: Mark McLoughlin Acked-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- virt/kvm/iommu.c | 6 ++---- virt/kvm/kvm_main.c | 3 +++ 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c index e9693a29d00e..4c4037503600 100644 --- a/virt/kvm/iommu.c +++ b/virt/kvm/iommu.c @@ -73,14 +73,13 @@ static int kvm_iommu_map_memslots(struct kvm *kvm) { int i, r = 0; - down_read(&kvm->slots_lock); for (i = 0; i < kvm->nmemslots; i++) { r = kvm_iommu_map_pages(kvm, kvm->memslots[i].base_gfn, kvm->memslots[i].npages); if (r) break; } - up_read(&kvm->slots_lock); + return r; } @@ -190,12 +189,11 @@ static void kvm_iommu_put_pages(struct kvm *kvm, static int kvm_iommu_unmap_memslots(struct kvm *kvm) { int i; - down_read(&kvm->slots_lock); + for (i = 0; i < kvm->nmemslots; i++) { kvm_iommu_put_pages(kvm, kvm->memslots[i].base_gfn, kvm->memslots[i].npages); } - up_read(&kvm->slots_lock); return 0; } diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d9bbb20f230f..29a667ce35b0 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -466,6 +466,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm, struct kvm_assigned_dev_kernel *match; struct pci_dev *dev; + down_read(&kvm->slots_lock); mutex_lock(&kvm->lock); match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, @@ -527,6 +528,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm, out: mutex_unlock(&kvm->lock); + up_read(&kvm->slots_lock); return r; out_list_del: list_del(&match->list); @@ -538,6 +540,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm, out_free: kfree(match); mutex_unlock(&kvm->lock); + up_read(&kvm->slots_lock); return r; } #endif -- GitLab