Hi Peter, On 8/16/19 6:00 AM, Peter Xu wrote: > On Tue, Jul 30, 2019 at 07:21:27PM +0200, Eric Auger wrote: > > [...] > >> static void virtio_iommu_get_config(VirtIODevice *vdev, uint8_t >> *config_data) >> { >> VirtIOIOMMU *dev = VIRTIO_IOMMU(vdev); >> @@ -266,6 +333,15 @@ static void virtio_iommu_device_realize(DeviceState >> *dev, Error **errp) >> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MAP_UNMAP); >> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS); >> virtio_add_feature(&s->features, VIRTIO_IOMMU_F_MMIO); >> + >> + memset(s->as_by_bus_num, 0, sizeof(s->as_by_bus_num)); >> + s->as_by_busptr = g_hash_table_new(NULL, NULL); > > VT-d was using g_hash_table_new_full() so that potentially VTDBus can > still be freed. Here for IOMMUPCIBus allocated in > virtio_iommu_find_add_as() I think it'll be leaked if we remove > entries in the hash table? > > So I started to wonder whether PCI/PCIe buses are allowed to be > plugged/unplugged after all because I never tried. With latest > 5.3.0-rc4 guest I gave it a shot and I see the error below. It could > be something that I did wrong or it could be simply that it's not > working at all. Have you tried anything like that? Michael/Alex?
I have never tried this on my end. However looking at docs/pcie_pci_bridge.txt it seems possible to hotplug a pcie_pci_bridge downstream to a pcie-root-port under specific conditions (see limitations section). So I guess the situation you describe may happen. I switched to _full version. Thanks Eric > > bin=x86_64-softmmu/qemu-system-x86_64 > $bin -M q35,accel=kvm,kernel-irqchip=on -smp 8 -m 2G -cpu host \ > -monitor telnet::6666,server,nowait -nographic \ > -device e1000,netdev=net0 \ > -netdev user,id=net0,hostfwd=tcp::5555-:22 \ > -device pcie-pci-bridge,bus=pcie.0,id=pci.1 \ > -drive file=/images/default.qcow2,if=none,cache=none,id=drive0 \ > -device virtio-blk,drive=drive0 > > (qemu) device_add pci-bridge,bus=pci.1,id=pci.2,chassis_nr=1,addr=1.0 > > [ 66.172352] pci 0000:01:01.0: [1b36:0001] type 01 class 0x060400 > [ 66.176897] pci 0000:01:01.0: reg 0x10: [mem 0x00000000-0x000000ff 64bit] > [ 66.186130] pci 0000:01:01.0: No bus number available for hot-added bridge > [ 66.189489] shpchp 0000:00:03.0: BAR 14: assigned [mem > 0x80000000-0x800fffff] > [ 66.193235] pci 0000:01:01.0: BAR 0: assigned [mem 0x80000000-0x800000ff > 64bit] > [ 66.198587] shpchp 0000:00:03.0: PCI bridge to [bus 01] > [ 66.204113] shpchp 0000:00:03.0: bridge window [mem > 0x80000000-0x800fffff] > [ 66.215212] shpchp 0000:01:01.0: HPC vendor_id 1b36 device_id 1 ss_vid 0 > ss_did 0 > [ 66.218531] shpchp 0000:01:01.0: enabling device (0000 -> 0002) > [ 66.229204] BUG: kernel NULL pointer dereference, address: 00000000000000e2 > [ 66.232124] #PF: supervisor write access in kernel mode > [ 66.234369] #PF: error_code(0x0002) - not-present page > [ 66.236585] PGD 0 P4D 0 > [ 66.237431] Oops: 0002 [#1] SMP PTI > [ 66.238617] CPU: 2 PID: 277 Comm: kworker/2:1 Kdump: loaded Not tainted > 5.3.0-rc4 #85 > [ 66.241200] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS > rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 > [ 66.244916] Workqueue: shpchp-1 shpchp_pushbutton_thread > [ 66.246583] RIP: 0010:shpc_init.cold+0x5c3/0x8a1 > [ 66.248041] Code: 24 90 01 00 00 8b 49 08 40 80 fe 02 0f 85 f4 01 00 00 f7 > c1 00 00 00 f0 0f 84 b2 01 00 00 b9 13 00 00 00 80 3d 33 40 38 02 00 <88> 8a > e26 > [ 66.253771] RSP: 0018:ffffc9000025bb68 EFLAGS: 00010246 > [ 66.255418] RAX: 00000000000000ff RBX: 0000000000000000 RCX: > 0000000000000000 > [ 66.257763] RDX: 0000000000000000 RSI: ffffffff826bcd01 RDI: > ffffffff826bcd60 > [ 66.260065] RBP: 0000000000000000 R08: 0000000000000001 R09: > 0000000000000000 > [ 66.263184] R10: 0000000000000005 R11: 0000000000000000 R12: > ffff888032425400 > [ 66.265706] R13: ffffc9000017109c R14: ffff888033da7000 R15: > 000000000000001f > [ 66.268200] FS: 0000000000000000(0000) GS:ffff88807fc80000(0000) > knlGS:0000000000000000 > [ 66.270826] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 66.272731] CR2: 00000000000000e2 CR3: 0000000033afc002 CR4: > 0000000000360ee0 > [ 66.275373] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > 0000000000000000 > [ 66.277947] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > 0000000000000400 > [ 66.279965] Call Trace: > [ 66.280627] shpc_probe+0x91/0x32b > [ 66.281644] local_pci_probe+0x42/0x80 > [ 66.282752] pci_device_probe+0x107/0x1a0 > [ 66.283877] really_probe+0xf0/0x380 > [ 66.284862] driver_probe_device+0x59/0xd0 > [ 66.285988] ? driver_allows_async_probing+0x50/0x50 > [ 66.287937] bus_for_each_drv+0x7e/0xc0 > [ 66.289752] __device_attach+0xe1/0x160 > [ 66.292076] pci_bus_add_device+0x4b/0x70 > [ 66.295244] pci_bus_add_devices+0x2c/0x64 > [ 66.297429] shpchp_configure_device+0xc1/0xe0 > [ 66.299692] board_added+0x117/0x240 > [ 66.301589] shpchp_enable_slot+0x121/0x2e0 > [ 66.303686] shpchp_pushbutton_thread+0x70/0xa0 > [ 66.305941] process_one_work+0x221/0x500 > [ 66.308253] worker_thread+0x50/0x3b0 > [ 66.310512] kthread+0xfb/0x130 > [ 66.312422] ? process_one_work+0x500/0x500 > [ 66.314617] ? kthread_park+0x80/0x80 > [ 66.316489] ret_from_fork+0x3a/0x50 > [ 66.318293] Modules linked in: intel_rapl_msr intel_rapl_common kvm_intel > kvm crct10dif_pclmul bochs_drm crc32_pclmul drm_vram_helper > ghash_clmulni_intel o > [ 66.331179] CR2: 00000000000000e2 > [ 66.333090] ---[ end trace cfc73b2e92e207d4 ]--- > [ 66.335431] RIP: 0010:shpc_init.cold+0x5c3/0x8a1 > [ 66.337790] Code: 24 90 01 00 00 8b 49 08 40 80 fe 02 0f 85 f4 01 00 00 f7 > c1 00 00 00 f0 0f 84 b2 01 00 00 b9 13 00 00 00 80 3d 33 40 38 02 00 <88> 8a > e26 > [ 66.346561] RSP: 0018:ffffc9000025bb68 EFLAGS: 00010246 > [ 66.348659] RAX: 00000000000000ff RBX: 0000000000000000 RCX: > 0000000000000000 > [ 66.351412] RDX: 0000000000000000 RSI: ffffffff826bcd01 RDI: > ffffffff826bcd60 > [ 66.354204] RBP: 0000000000000000 R08: 0000000000000001 R09: > 0000000000000000 > [ 66.357013] R10: 0000000000000005 R11: 0000000000000000 R12: > ffff888032425400 > [ 66.360117] R13: ffffc9000017109c R14: ffff888033da7000 R15: > 000000000000001f > [ 66.362953] FS: 0000000000000000(0000) GS:ffff88807fc80000(0000) > knlGS:0000000000000000 > [ 66.366003] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 66.368756] CR2: 00000000000000e2 CR3: 0000000033afc002 CR4: > 0000000000360ee0 > [ 66.371769] DR0: 0000000000000000 DR1: 0000000000000000 DR2: > 0000000000000000 > [ 66.376036] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: > 0000000000000400 > > Regards, >