forked from luck/tmp_suning_uos_patched
KVM: Enable snooping control for supported hardware
Memory aliases with different memory type is a problem for guest. For the guest without assigned device, the memory type of guest memory would always been the same as host(WB); but for the assigned device, some part of memory may be used as DMA and then set to uncacheable memory type(UC/WC), which would be a conflict of host memory type then be a potential issue. Snooping control can guarantee the cache correctness of memory go through the DMA engine of VT-d. [avi: fix build on ia64] Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
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@ -474,6 +474,7 @@ struct kvm_arch {
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struct list_head assigned_dev_head;
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struct iommu_domain *iommu_domain;
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int iommu_flags;
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struct hlist_head irq_ack_notifier_list;
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unsigned long irq_sources_bitmap;
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@ -393,6 +393,7 @@ struct kvm_arch{
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struct list_head active_mmu_pages;
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struct list_head assigned_dev_head;
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struct iommu_domain *iommu_domain;
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int iommu_flags;
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struct kvm_pic *vpic;
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struct kvm_ioapic *vioapic;
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struct kvm_pit *vpit;
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@ -3581,11 +3581,26 @@ static u64 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
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{
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u64 ret;
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/* For VT-d and EPT combination
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* 1. MMIO: always map as UC
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* 2. EPT with VT-d:
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* a. VT-d without snooping control feature: can't guarantee the
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* result, try to trust guest.
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* b. VT-d with snooping control feature: snooping control feature of
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* VT-d engine can guarantee the cache correctness. Just set it
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* to WB to keep consistent with host. So the same as item 3.
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* 3. EPT without VT-d: always map as WB and set IGMT=1 to keep
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* consistent with host MTRR
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*/
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if (is_mmio)
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ret = MTRR_TYPE_UNCACHABLE << VMX_EPT_MT_EPTE_SHIFT;
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else if (vcpu->kvm->arch.iommu_domain &&
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!(vcpu->kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY))
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ret = kvm_get_guest_memory_type(vcpu, gfn) <<
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VMX_EPT_MT_EPTE_SHIFT;
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else
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ret = (kvm_get_guest_memory_type(vcpu, gfn) <<
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VMX_EPT_MT_EPTE_SHIFT) | VMX_EPT_IGMT_BIT;
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ret = (MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT)
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| VMX_EPT_IGMT_BIT;
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return ret;
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}
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@ -367,6 +367,9 @@ void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian);
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int kvm_request_irq_source_id(struct kvm *kvm);
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void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
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/* For vcpu->arch.iommu_flags */
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#define KVM_IOMMU_CACHE_COHERENCY 0x1
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#ifdef CONFIG_IOMMU_API
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int kvm_iommu_map_pages(struct kvm *kvm, gfn_t base_gfn,
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unsigned long npages);
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@ -39,11 +39,16 @@ int kvm_iommu_map_pages(struct kvm *kvm,
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pfn_t pfn;
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int i, r = 0;
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struct iommu_domain *domain = kvm->arch.iommu_domain;
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int flags;
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/* check if iommu exists and in use */
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if (!domain)
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return 0;
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flags = IOMMU_READ | IOMMU_WRITE;
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if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
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flags |= IOMMU_CACHE;
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for (i = 0; i < npages; i++) {
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/* check if already mapped */
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if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn)))
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@ -53,8 +58,7 @@ int kvm_iommu_map_pages(struct kvm *kvm,
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r = iommu_map_range(domain,
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gfn_to_gpa(gfn),
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pfn_to_hpa(pfn),
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PAGE_SIZE,
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IOMMU_READ | IOMMU_WRITE);
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PAGE_SIZE, flags);
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if (r) {
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printk(KERN_ERR "kvm_iommu_map_address:"
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"iommu failed to map pfn=%lx\n", pfn);
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@ -88,7 +92,7 @@ int kvm_assign_device(struct kvm *kvm,
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{
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struct pci_dev *pdev = NULL;
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struct iommu_domain *domain = kvm->arch.iommu_domain;
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int r;
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int r, last_flags;
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/* check if iommu exists and in use */
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if (!domain)
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@ -107,12 +111,29 @@ int kvm_assign_device(struct kvm *kvm,
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return r;
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}
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last_flags = kvm->arch.iommu_flags;
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if (iommu_domain_has_cap(kvm->arch.iommu_domain,
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IOMMU_CAP_CACHE_COHERENCY))
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kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY;
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/* Check if need to update IOMMU page table for guest memory */
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if ((last_flags ^ kvm->arch.iommu_flags) ==
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KVM_IOMMU_CACHE_COHERENCY) {
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kvm_iommu_unmap_memslots(kvm);
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r = kvm_iommu_map_memslots(kvm);
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if (r)
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goto out_unmap;
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}
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printk(KERN_DEBUG "assign device: host bdf = %x:%x:%x\n",
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assigned_dev->host_busnr,
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PCI_SLOT(assigned_dev->host_devfn),
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PCI_FUNC(assigned_dev->host_devfn));
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return 0;
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out_unmap:
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kvm_iommu_unmap_memslots(kvm);
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return r;
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}
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int kvm_deassign_device(struct kvm *kvm,
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