Re: [PATCH v2 0/5] memory: Skip assertion in memory_region_unregister_iommu_notifier

[Jason Wang <jasowang@redhat.com>]

On 2020/10/19 下午6:42, Eugenio Pérez wrote:
> I am able to hit this assertion when a Red Hat 7 guest virtio_net device
> raises an "Invalidation" of all the TLB entries. This happens in the
> guest's startup if 'intel_iommu=on' argument is passed to the guest
> kernel and right IOMMU/ATS devices are declared in qemu's command line.
>
> Command line:
> /home/qemu/x86_64-softmmu/qemu-system-x86_64 -name \
> guest=rhel7-test,debug-threads=on -machine \
> pc-q35-5.1,accel=kvm,usb=off,dump-guest-core=off,kernel_irqchip=split \
> -cpu \
> Broadwell,vme=on,ss=on,vmx=on,f16c=on,rdrand=on,hypervisor=on,arat=on,tsc-adjust=on,umip=on,arch-capabilities=on,xsaveopt=on,pdpe1gb=on,abm=on,skip-l1dfl-vmentry=on,rtm=on,hle=on \
> -m 8096 -realtime mlock=off -smp 2,sockets=2,cores=1,threads=1 -uuid \
> d022ecbf-679e-4755-87ce-eb87fc5bbc5d -display none -no-user-config \
> -nodefaults -rtc base=utc,driftfix=slew -global \
> kvm-pit.lost_tick_policy=delay -no-hpet -no-shutdown -global \
> ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on \
> -device intel-iommu,intremap=on,device-iotlb=on -device \
> pcie-root-port,port=0x8,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x1 \
> -device \
> pcie-root-port,port=0x9,chassis=2,id=pci.2,bus=pcie.0,addr=0x1.0x1 \
> -device \
> pcie-root-port,port=0xa,chassis=3,id=pci.3,bus=pcie.0,addr=0x1.0x2 \
> -device \
> pcie-root-port,port=0xb,chassis=4,id=pci.4,bus=pcie.0,addr=0x1.0x3 \
> -device \
> pcie-root-port,port=0xc,chassis=5,id=pci.5,bus=pcie.0,addr=0x1.0x4 \
> -device \
> pcie-root-port,port=0xd,chassis=6,id=pci.6,bus=pcie.0,addr=0x1.0x5 \
> -device \
> pcie-root-port,port=0xe,chassis=7,id=pci.7,bus=pcie.0,addr=0x1.0x6 \
> -device qemu-xhci,p2=15,p3=15,id=usb,bus=pci.2,addr=0x0 -device \
> virtio-serial-pci,id=virtio-serial0,bus=pci.3,addr=0x0 -drive \
> file=/home/virtio-test2.qcow2,format=qcow2,if=none,id=drive-virtio-disk0 \
> -device \
> virtio-blk-pci,scsi=off,bus=pci.4,addr=0x0,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \
> -netdev tap,id=hostnet0,vhost=on,vhostforce=on -device \
> virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:0d:1d:f2,bus=pci.1,addr=0x0,iommu_platform=on,ats=on \
> -device virtio-balloon-pci,id=balloon0,bus=pci.5,addr=0x0 -object \
> rng-random,id=objrng0,filename=/dev/urandom -device \
> virtio-rng-pci,rng=objrng0,id=rng0,bus=pci.6,addr=0x0 -s -msg \
> timestamp=on
>
> Full backtrace:
>   #0  0x00007ffff521370f in raise () at /lib64/libc.so.6
>   #1  0x00007ffff51fdb25 in abort () at /lib64/libc.so.6
>   #2  0x00007ffff51fd9f9 in _nl_load_domain.cold.0 () at /lib64/libc.so.6
>   #3  0x00007ffff520bcc6 in .annobin_assert.c_end () at /lib64/libc.so.6
>   #4  0x0000555555888171 in memory_region_notify_one (notifier=0x7ffde0487fa8,
>                                                      entry=0x7ffde5dfe200)
>                            at /home/qemu/memory.c:1918
>   #5  0x0000555555888247 in memory_region_notify_iommu (iommu_mr=0x555556f6c0b0,
>                                                        iommu_idx=0, entry=...)
>                            at /home/qemu/memory.c:1941
>   #6  0x0000555555951c8d in vtd_process_device_iotlb_desc (s=0x555557609000,
>                                                         inv_desc=0x7ffde5dfe2d0)
>                            at /home/qemu/hw/i386/intel_iommu.c:2468
>   #7  0x0000555555951e6a in vtd_process_inv_desc (s=0x555557609000)
>                            at /home/qemu/hw/i386/intel_iommu.c:2531
>   #8  0x0000555555951fa5 in vtd_fetch_inv_desc (s=0x555557609000)
>                            at /home/qemu/hw/i386/intel_iommu.c:2563
>   #9  0x00005555559520e5 in vtd_handle_iqt_write (s=0x555557609000)
>                            at /home/qemu/hw/i386/intel_iommu.c:2590
>   #10 0x0000555555952b45 in vtd_mem_write (opaque=0x555557609000, addr=136,
>                                           val=2688, size=4)
>                            at /home/qemu/hw/i386/intel_iommu.c:2837
>   #11 0x0000555555883e17 in memory_region_write_accessor (mr=0x555557609330,
>                                                          addr=136,
>                                                          value=0x7ffde5dfe478,
>                                                          size=4,
>                                                          shift=0,
>                                                          mask=4294967295,
>                                                          attrs=...)
>                           at /home/qemu/memory.c:483
>   #12 0x000055555588401d in access_with_adjusted_size (addr=136,
>                         value=0x7ffde5dfe478,
>                         size=4,
>                         access_size_min=4,
>                         access_size_max=8,
>                         access_fn=0x555555883d38 <memory_region_write_accessor>,
>                         mr=0x555557609330,
>                         attrs=...)
>                         at /home/qemu/memory.c:544
>   #13 0x0000555555886f37 in memory_region_dispatch_write (mr=0x555557609330,
>                                                         addr=136,
>                                                         data=2688,
>                                                         op=MO_32,
>                                                         attrs=...)
>                           at /home/qemu/memory.c:1476
>   #14 0x0000555555827a03 in flatview_write_continue (fv=0x7ffdd8503150,
>                                                     addr=4275634312,
>                                                     attrs=...,
>                                                     ptr=0x7ffff7ff0028,
>                                                     len=4,
>                                                     addr1=136,
>                                                     l=4,
>                                                     mr=0x555557609330)
>                            at /home/qemu/exec.c:3146
>   #15 0x0000555555827b48 in flatview_write (fv=0x7ffdd8503150,
>                                            addr=4275634312,
>                                            attrs=...,
>                                            buf=0x7ffff7ff0028,
>                                            len=4)
>                            at /home/qemu/exec.c:3186
>   #16 0x0000555555827e9d in address_space_write (
>                                        as=0x5555567ca640 <address_space_memory>,
>                                        addr=4275634312,
>                                        attrs=...,
>                                        buf=0x7ffff7ff0028,
>                                        len=4)
>                            at /home/qemu/exec.c:3277
>   #17 0x0000555555827f0a in address_space_rw (
>                                        as=0x5555567ca640 <address_space_memory>,
>                                        addr=4275634312,
>                                        attrs=...,
>                                        buf=0x7ffff7ff0028,
>                                        len=4,
>                                        is_write=true)
>                            at /home/qemu/exec.c:3287
>   #18 0x000055555589b633 in kvm_cpu_exec (cpu=0x555556b65640)
>                                 at /home/qemu/accel/kvm/kvm-all.c:2511
>   #19 0x0000555555876ba8 in qemu_kvm_cpu_thread_fn (arg=0x555556b65640)
>                                 at /home/qemu/cpus.c:1284
>   #20 0x0000555555dafff1 in qemu_thread_start (args=0x555556b8c3b0)
>                                 at util/qemu-thread-posix.c:521
>   #21 0x00007ffff55a62de in start_thread () at /lib64/libpthread.so.0
>   #22 0x00007ffff52d7e83 in clone () at /lib64/libc.so.6
>
> (gdb) frame 4
>   #4  0x0000555555888171 in memory_region_notify_one
>                        (notifier=0x7ffde0487fa8, entry=0x7ffde5dfe200)
>                        at /home/qemu/memory.c:1918
> 1918        assert(entry->iova >= notifier->start && entry_end <=
> notifier->end);
> (gdb) p *entry
> $1 = {target_as = 0x555556f6c050, iova = 0, translated_addr = 0,
> addr_mask = 18446744073709551615, perm = IOMMU_NONE}
> --
>
> Tested with vhost-net and qemu driver, host<->guest communication.
>
> v2: * Delete underflow assertion
>      * Tested again rebased over ("3e407488349 Merge remote-tracking
>        branch 'remotes/rth/tags/pull-mb-20201014' into staging")
>
> v1: * IOMMU_NOTIFIER_ALL now includes IOMMU_NOTIFIER_DEVIOTLB_EVENTS
>        also. VFIO IOMMU notifier will register for all events (as before
>        of the patching)
>      * Cosmetic changes, like:
>        - Expand commit messages
>        - Better naming and checks
>        - Fix alignment issues
>        - Avoid an already present casting from `void *`
>   at https://lists.gnu.org/archive/html/qemu-devel/2020-09/msg01505.html
>
> RFC v8: Fix use of "tmp" notification in memory.c:memory_region_notify_iommu_one
>
> v7: Add IOMMUTLBNotification, and move introduced "type" from
>      IOMMUTLBEntry to the former.
>
> v6: Introduce "type" field for IOMMUTLBEntry. Fill in all uses.
>      Update tests reports with more fine-tuning (CPU, RPS/XPS tunning).
>
> v5: Skip regular IOTLB notifications in dev_iotlb notifiers
>
> v4: Rename IOMMU_NOTIFIER_IOTLB -> IOMMU_NOTIFIER_DEVIOTLB.
>      Make vhost-net notifier just IOMMU_NOTIFIER_DEVIOTLB, not
>      IOMMU_NOTIFIER_UNMAP
>
> v3: Skip the assertion in case notifier is a IOTLB one, since they can manage
>      arbitrary ranges. Using a flag in the notifier for now, as Peter suggested.
>
> v2: Actually delete assertion instead of just commenting out using C99
>
> Eugenio Pérez (5):
>    memory: Rename memory_region_notify_one to
>      memory_region_notify_iommu_one
>    memory: Add IOMMUTLBEvent
>    memory: Add IOMMU_NOTIFIER_DEVIOTLB_UNMAP IOMMUTLBNotificationType
>    intel_iommu: Skip page walking on device iotlb invalidations
>    memory: Skip bad range assertion if notifier is DEVIOTLB_UNMAP type
>
>   include/exec/memory.h | 40 ++++++++++---------
>   hw/arm/smmu-common.c  | 13 +++---
>   hw/arm/smmuv3.c       | 13 +++---
>   hw/i386/intel_iommu.c | 92 +++++++++++++++++++++++++------------------
>   hw/misc/tz-mpc.c      | 32 ++++++++-------
>   hw/ppc/spapr_iommu.c  | 15 +++----
>   hw/virtio/vhost.c     |  2 +-
>   softmmu/memory.c      | 30 ++++++++------
>   8 files changed, 134 insertions(+), 103 deletions(-)


Acked-by: Jason Wang <jasowang@redhat.com>

Thanks


>