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* kvm: fix excessive pages un-pinning in kvm_iommu_map error path.Quentin Casasnovas2014-12-141-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3d32e4dbe71374a6780eaf51d719d76f9a9bf22f upstream. The third parameter of kvm_unpin_pages() when called from kvm_iommu_map_pages() is wrong, it should be the number of pages to un-pin and not the page size. This error was facilitated with an inconsistent API: kvm_pin_pages() takes a size, but kvn_unpin_pages() takes a number of pages, so fix the problem by matching the two. This was introduced by commit 350b8bd ("kvm: iommu: fix the third parameter of kvm_iommu_put_pages (CVE-2014-3601)"), which fixes the lack of un-pinning for pages intended to be un-pinned (i.e. memory leak) but unfortunately potentially aggravated the number of pages we un-pin that should have stayed pinned. As far as I understand though, the same practical mitigations apply. This issue was found during review of Red Hat 6.6 patches to prepare Ksplice rebootless updates. Thanks to Vegard for his time on a late Friday evening to help me in understanding this code. Fixes: 350b8bd ("kvm: iommu: fix the third parameter of... (CVE-2014-3601)") Cc: stable@vger.kernel.org Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Jamie Iles <jamie.iles@oracle.com> Reviewed-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2: kvm_pin_pages() also takes a struct kvm *kvm param] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* kvm: iommu: fix the third parameter of kvm_iommu_put_pages (CVE-2014-3601)Michael S. Tsirkin2014-09-131-9/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 350b8bdd689cd2ab2c67c8a86a0be86cfa0751a7 upstream. The third parameter of kvm_iommu_put_pages is wrong, It should be 'gfn - slot->base_gfn'. By making gfn very large, malicious guest or userspace can cause kvm to go to this error path, and subsequently to pass a huge value as size. Alternatively if gfn is small, then pages would be pinned but never unpinned, causing host memory leak and local DOS. Passing a reasonable but large value could be the most dangerous case, because it would unpin a page that should have stayed pinned, and thus allow the device to DMA into arbitrary memory. However, this cannot happen because of the condition that can trigger the error: - out of memory (where you can't allocate even a single page) should not be possible for the attacker to trigger - when exceeding the iommu's address space, guest pages after gfn will also exceed the iommu's address space, and inside kvm_iommu_put_pages() the iommu_iova_to_phys() will fail. The page thus would not be unpinned at all. Reported-by: Jack Morgenstein <jackm@mellanox.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* KVM: IOMMU: hva align mapping page sizeGreg Edwards2014-01-031-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 27ef63c7e97d1e5dddd85051c03f8d44cc887f34 upstream. When determining the page size we could use to map with the IOMMU, the page size should also be aligned with the hva, not just the gfn. The gfn may not reflect the real alignment within the hugetlbfs file. Most of the time, this works fine. However, if the hugetlbfs file is backed by non-contiguous huge pages, a multi-huge page memslot starts at an unaligned offset within the hugetlbfs file, and the gfn is aligned with respect to the huge page size, kvm_host_page_size() will return the huge page size and we will use that to map with the IOMMU. When we later unpin that same memslot, the IOMMU returns the unmap size as the huge page size, and we happily unpin that many pfns in monotonically increasing order, not realizing we are spanning non-contiguous huge pages and partially unpin the wrong huge page. Ensure the IOMMU mapping page size is aligned with the hva corresponding to the gfn, which does reflect the alignment within the hugetlbfs file. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Greg Edwards <gedwards@ddn.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> [bwh: Backported to 3.2: s/__gfn_to_hva_memslot/gfn_to_hva_memslot/] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* KVM: lock slots_lock around device assignmentAlex Williamson2012-05-311-8/+15
| | | | | | | | | | | | | | | | | | | (cherry picked from commit 21a1416a1c945c5aeaeaf791b63c64926018eb77) 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 <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* KVM: unmap pages from the iommu when slots are removedAlex Williamson2012-05-111-4/+8
| | | | | | | | | | | | | | | | | | | | | | | commit 32f6daad4651a748a58a3ab6da0611862175722f upstream. 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 <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* kvm: iommu.c file requires the full module.h present.Paul Gortmaker2011-10-311-0/+1
| | | | | | | | | | | | | This file has things like module_param_named() and MODULE_PARM_DESC() so it needs the full module.h header present. Without it, you'll get: CC arch/x86/kvm/../../../virt/kvm/iommu.o virt/kvm/iommu.c:37: error: expected ‘)’ before ‘bool’ virt/kvm/iommu.c:39: error: expected ‘)’ before string constant make[3]: *** [arch/x86/kvm/../../../virt/kvm/iommu.o] Error 1 make[2]: *** [arch/x86/kvm] Error 2 Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* kvm: fix implicit use of stat.h header filePaul Gortmaker2011-10-311-0/+1
| | | | | | | | This was coming in via an implicit module.h (and its sub-includes) before, but we'll be cleaning that up shortly. Call out the stat.h include requirement in advance. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommuLinus Torvalds2011-10-301-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (33 commits) iommu/core: Remove global iommu_ops and register_iommu iommu/msm: Use bus_set_iommu instead of register_iommu iommu/omap: Use bus_set_iommu instead of register_iommu iommu/vt-d: Use bus_set_iommu instead of register_iommu iommu/amd: Use bus_set_iommu instead of register_iommu iommu/core: Use bus->iommu_ops in the iommu-api iommu/core: Convert iommu_found to iommu_present iommu/core: Add bus_type parameter to iommu_domain_alloc Driver core: Add iommu_ops to bus_type iommu/core: Define iommu_ops and register_iommu only with CONFIG_IOMMU_API iommu/amd: Fix wrong shift direction iommu/omap: always provide iommu debug code iommu/core: let drivers know if an iommu fault handler isn't installed iommu/core: export iommu_set_fault_handler() iommu/omap: Fix build error with !IOMMU_SUPPORT iommu/omap: Migrate to the generic fault report mechanism iommu/core: Add fault reporting mechanism iommu/core: Use PAGE_SIZE instead of hard-coded value iommu/core: use the existing IS_ALIGNED macro iommu/msm: ->unmap() should return order of unmapped page ... Fixup trivial conflicts in drivers/iommu/Makefile: "move omap iommu to dedicated iommu folder" vs "Rename the DMAR and INTR_REMAP config options" just happened to touch lines next to each other.
| * iommu/core: Convert iommu_found to iommu_presentJoerg Roedel2011-10-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | With per-bus iommu_ops the iommu_found function needs to work on a bus_type too. This patch adds a bus_type parameter to that function and converts all call-places. The function is also renamed to iommu_present because the function now checks if an iommu is present for a given bus and does not check for a global iommu anymore. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
| * iommu/core: Add bus_type parameter to iommu_domain_allocJoerg Roedel2011-10-211-1/+1
| | | | | | | | | | | | | | | | This is necessary to store a pointer to the bus-specific iommu_ops in the iommu-domain structure. It will be used later to call into bus-specific iommu-ops. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* | pci: Add flag indicating device has been assigned by KVMGreg Rose2011-09-231-0/+4
|/ | | | | | | | | | | | | | | | Device drivers that create and destroy SR-IOV virtual functions via calls to pci_enable_sriov() and pci_disable_sriov can cause catastrophic failures if they attempt to destroy VFs while they are assigned to guest virtual machines. By adding a flag for use by the KVM module to indicate that a device is assigned a device driver can check that flag and avoid destroying VFs while they are assigned and avoid system failures. CC: Ian Campbell <ijc@hellion.org.uk> CC: Konrad Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Rose <gregory.v.rose@intel.com> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
* KVM: IOMMU: Disable device assignment without interrupt remappingAlex Williamson2011-07-241-0/+18
| | | | | | | | | | | | | | | | | | | | IOMMU interrupt remapping support provides a further layer of isolation for device assignment by preventing arbitrary interrupt block DMA writes by a malicious guest from reaching the host. By default, we should require that the platform provides interrupt remapping support, with an opt-in mechanism for existing behavior. Both AMD IOMMU and Intel VT-d2 hardware support interrupt remapping, however we currently only have software support on the Intel side. Users wishing to re-enable device assignment when interrupt remapping is not supported on the platform can use the "allow_unsafe_assigned_interrupts=1" module option. [avi: break long lines] Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Use u64 for frame data typesJoerg Roedel2010-08-021-1/+1
| | | | | | | | | | | | For 32bit machines where the physical address width is larger than the virtual address width the frame number types in KVM may overflow. Fix this by changing them to u64. [sfr: fix build on 32-bit ppc] Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Fix IOMMU memslot reference warningSheng Yang2010-08-011-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the following warning. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- include/linux/kvm_host.h:259 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 no locks held by qemu-system-x86/29679. stack backtrace: Pid: 29679, comm: qemu-system-x86 Not tainted 2.6.35-rc3+ #200 Call Trace: [<ffffffff810a224e>] lockdep_rcu_dereference+0xa8/0xb1 [<ffffffffa018a06f>] kvm_iommu_unmap_memslots+0xc9/0xde [kvm] [<ffffffffa018a0c4>] kvm_iommu_unmap_guest+0x40/0x4e [kvm] [<ffffffffa018f772>] kvm_arch_destroy_vm+0x1a/0x186 [kvm] [<ffffffffa01800d0>] kvm_put_kvm+0x110/0x167 [kvm] [<ffffffffa0180ecc>] kvm_vcpu_release+0x18/0x1c [kvm] [<ffffffff81156f5d>] fput+0x22a/0x3a0 [<ffffffff81152288>] filp_close+0xb4/0xcd [<ffffffff8106599f>] put_files_struct+0x1b7/0x36b [<ffffffff81065830>] ? put_files_struct+0x48/0x36b [<ffffffff8131ee59>] ? do_raw_spin_unlock+0x118/0x160 [<ffffffff81065bc0>] exit_files+0x6d/0x75 [<ffffffff81068348>] do_exit+0x47d/0xc60 [<ffffffff8177e7b5>] ? _raw_spin_unlock_irq+0x30/0x36 [<ffffffff81068bfa>] do_group_exit+0xcf/0x134 [<ffffffff81080790>] get_signal_to_deliver+0x732/0x81d [<ffffffff81095996>] ? cpu_clock+0x4e/0x60 [<ffffffff81002082>] do_notify_resume+0x117/0xc43 [<ffffffff810a2fa3>] ? trace_hardirqs_on+0xd/0xf [<ffffffff81080d79>] ? sys_rt_sigtimedwait+0x2b5/0x3bf [<ffffffff8177d9f2>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff81003221>] ? sysret_signal+0x5/0x3d [<ffffffff8100343b>] int_signal+0x12/0x17 Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Update Red Hat copyrightsAvi Kivity2010-08-011-0/+2
| | | | Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Fix order passed to iommu_unmapJan Kiszka2010-06-091-1/+1
| | | | | | | | | | This is obviously a left-over from the the old interface taking the size. Apparently a mostly harmless issue with the current iommu_unmap implementation. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Acked-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* Merge branch 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2010-05-211-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'kvm-updates/2.6.35' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (269 commits) KVM: x86: Add missing locking to arch specific vcpu ioctls KVM: PPC: Add missing vcpu_load()/vcpu_put() in vcpu ioctls KVM: MMU: Segregate shadow pages with different cr0.wp KVM: x86: Check LMA bit before set_efer KVM: Don't allow lmsw to clear cr0.pe KVM: Add cpuid.txt file KVM: x86: Tell the guest we'll warn it about tsc stability x86, paravirt: don't compute pvclock adjustments if we trust the tsc x86: KVM guest: Try using new kvm clock msrs KVM: x86: export paravirtual cpuid flags in KVM_GET_SUPPORTED_CPUID KVM: x86: add new KVMCLOCK cpuid feature KVM: x86: change msr numbers for kvmclock x86, paravirt: Add a global synchronization point for pvclock x86, paravirt: Enable pvclock flags in vcpu_time_info structure KVM: x86: Inject #GP with the right rip on efer writes KVM: SVM: Don't allow nested guest to VMMCALL into host KVM: x86: Fix exception reinjection forced to true KVM: Fix wallclock version writing race KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_roots KVM: VMX: enable VMXON check with SMX enabled (Intel TXT) ...
| * KVM: use the correct RCU API for PROVE_RCU=yLai Jiangshan2010-05-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The RCU/SRCU API have already changed for proving RCU usage. I got the following dmesg when PROVE_RCU=y because we used incorrect API. This patch coverts rcu_deference() to srcu_dereference() or family API. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by qemu-system-x86/8550: #0: (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm] #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm] stack backtrace: Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27 Call Trace: [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm] [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm] [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm] [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm] [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel] [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm] [<ffffffff810a8692>] ? unlock_page+0x27/0x2c [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm] [<ffffffff81060cfa>] ? up_read+0x23/0x3d [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a [<ffffffff810021db>] system_call_fastpath+0x16/0x1b Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* | kvm: Change kvm_iommu_map_pages to map large pagesJoerg Roedel2010-03-071-22/+91
|/ | | | | | | | | This patch changes the implementation of of kvm_iommu_map_pages to map the pages with the host page size into the io virtual address space. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Acked-By: Avi Kivity <avi@redhat.com>
* KVM: enable PCI multiple-segments for pass-through deviceZhai, Edwin2010-03-011-3/+6
| | | | | | | | | Enable optional parameter (default 0) - PCI segment (or domain) besides BDF, when assigning PCI device to guest. Signed-off-by: Zhai Edwin <edwin.zhai@intel.com> Acked-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU updateMarcelo Tosatti2010-03-011-2/+2
| | | | | | | | | | Use two steps for memslot deletion: mark the slot invalid (which stops instantiation of new shadow pages for that slot, but allows destruction), then instantiate the new empty slot. Also simplifies kvm_handle_hva locking. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: use gfn_to_pfn_memslot in kvm_iommu_map_pagesMarcelo Tosatti2010-03-011-7/+6
| | | | | | | So its possible to iommu map a memslot before making it visible to kvm. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: modify memslots layout in struct kvmMarcelo Tosatti2010-03-011-6/+12
| | | | | | | | | Have a pointer to an allocated region inside struct kvm. [alex: fix ppc book 3s] Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Enable snooping control for supported hardwareSheng Yang2009-06-101-3/+24
| | | | | | | | | | | | | | | | 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>
* KVM: Fix assigned devices circular locking dependencyMark McLoughlin2009-02-151-4/+2
| | | | | | | | | | | 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 <markmc@redhat.com> Acked-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* kvm/iommu: fix compile warningJoerg Roedel2009-01-031-1/+1
| | | | | | | This fixes a compile warning about a variable thats maybe used uninitialized in the function. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* KVM: change KVM to use IOMMU APIJoerg Roedel2009-01-031-24/+21
| | | | Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* KVM: rename vtd.c to iommu.cJoerg Roedel2009-01-031-0/+217
Impact: file renamed The code in the vtd.c file can be reused for other IOMMUs as well. So rename it to make it clear that it handle more than VT-d. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>