linux/virt, branch v3.4

KVM: lock slots_lock around device assignment

2012-04-19T03:04:18Z

As pointed out by Jason Baron, when assigning a device to a guest we first set the iommu domain pointer, which enables mapping and unmapping of memory slots to the iommu. This leaves a window where this path is enabled, but we haven't synchronized the iommu mappings to the existing memory slots. Thus a slot being removed at that point could send us down unexpected code paths removing non-existent pinnings and iommu mappings. Take the slots_lock around creating the iommu domain and initial mappings as well as around iommu teardown to avoid this race. Signed-off-by: Alex Williamson Signed-off-by: Marcelo Tosatti

KVM: unmap pages from the iommu when slots are removed

2012-04-12T01:55:25Z

We've been adding new mappings, but not destroying old mappings. This can lead to a page leak as pages are pinned using get_user_pages, but only unpinned with put_page if they still exist in the memslots list on vm shutdown. A memslot that is destroyed while an iommu domain is enabled for the guest will therefore result in an elevated page reference count that is never cleared. Additionally, without this fix, the iommu is only programmed with the first translation for a gpa. This can result in peer-to-peer errors if a mapping is destroyed and replaced by a new mapping at the same gpa as the iommu will still be pointing to the original, pinned memory address. Signed-off-by: Alex Williamson Signed-off-by: Marcelo Tosatti

KVM: Convert intx_mask_lock to spin lock

2012-03-20T10:41:24Z

As kvm_notify_acked_irq calls kvm_assigned_dev_ack_irq under rcu_read_lock, we cannot use a mutex in the latter function. Switch to a spin lock to address this. Signed-off-by: Jan Kiszka Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity

KVM: use correct tlbs dirty type in cmpxchg

2012-03-08T12:11:44Z

Using 'int' type is not suitable for a 'long' object. So, correct it. Signed-off-by: Alex Shi Signed-off-by: Avi Kivity

KVM: Allow host IRQ sharing for assigned PCI 2.3 devices

2012-03-08T12:11:36Z

PCI 2.3 allows to generically disable IRQ sources at device level. This enables us to share legacy IRQs of such devices with other host devices when passing them to a guest. The new IRQ sharing feature introduced here is optional, user space has to request it explicitly. Moreover, user space can inform us about its view of PCI_COMMAND_INTX_DISABLE so that we can avoid unmasking the interrupt and signaling it if the guest masked it via the virtualized PCI config space. Signed-off-by: Jan Kiszka Acked-by: Alex Williamson Acked-by: Michael S. Tsirkin Signed-off-by: Avi Kivity

KVM: Ensure all vcpus are consistent with in-kernel irqchip settings

2012-03-08T12:10:30Z

If some vcpus are created before KVM_CREATE_IRQCHIP, then irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading to potential NULL pointer dereferences. Fix by: - ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called - ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP This is somewhat long winded because vcpu->arch.apic is created without kvm->lock held. Based on earlier patch by Michael Ellerman. Signed-off-by: Michael Ellerman Signed-off-by: Avi Kivity

KVM: mmu_notifier: Flush TLBs before releasing mmu_lock

2012-03-08T12:10:23Z

Other threads may process the same page in that small window and skip TLB flush and then return before these functions do flush. Signed-off-by: Takuya Yoshikawa Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity

KVM: Introduce kvm_memory_slot::arch and move lpage_info into it

2012-03-08T12:10:22Z

Some members of kvm_memory_slot are not used by every architecture. This patch is the first step to make this difference clear by introducing kvm_memory_slot::arch; lpage_info is moved into it. Signed-off-by: Takuya Yoshikawa Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity

KVM: Simplify ifndef conditional usage in __kvm_set_memory_region()

2012-03-08T12:10:21Z

Narrow down the controlled text inside the conditional so that it will include lpage_info and rmap stuff only. For this we change the way we check whether the slot is being created from "if (npages && !new.rmap)" to "if (npages && !old.npages)". We also stop checking if lpage_info is NULL when we create lpage_info because we do it from inside the slot creation code block. Signed-off-by: Takuya Yoshikawa Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity

KVM: Split lpage_info creation out from __kvm_set_memory_region()

2012-03-08T12:10:20Z

This makes it easy to make lpage_info architecture specific. Signed-off-by: Takuya Yoshikawa Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity