On Tue, Aug 13, 2024 at 12:28:41PM -0700, Si-Wei Liu wrote:
>
> Turning out this below commit to unconditionally enable premapped
> virtio-net:
>
> commit f9dac92ba9081062a6477ee015bd3b8c5914efc4
> Author: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> Date: Sat May 11 11:14:01 2024 +0800
>
> leads to regression on VM with no ACCESS_PLATFORM, and with the sysctl value
> of:
>
> - net.core.high_order_alloc_disable=1
>
> which could see reliable crashes or scp failure (scp a file 100M in size to
> VM):
>
> [ 332.079333] __vm_enough_memory: pid: 18440, comm: sshd, bytes:
> 5285790347661783040 not enough memory for the allocation
> [ 332.079651] ------------[ cut here ]------------
> [ 332.079655] kernel BUG at mm/mmap.c:3514!
> [ 332.080095] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
> [ 332.080826] CPU: 18 PID: 18440 Comm: sshd Kdump: loaded Not tainted
> 6.10.0-2.x86_64 #2
> [ 332.081514] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
> 1.16.0-4.module+el8.9.0+90173+a3f3e83a 04/01/2014
> [ 332.082451] RIP: 0010:exit_mmap+0x3a1/0x3b0
> [ 332.082871] Code: be 01 00 00 00 48 89 df e8 0c 94 fe ff eb d7 be 01 00
> 00 00 48 89 df e8 5d 98 fe ff eb be 31 f6 48 89 df e8 31 99 fe ff eb a8 <0f>
> 0b e8 68 bc ae 00 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90
> [ 332.084230] RSP: 0018:ffff9988b1c8f948 EFLAGS: 00010293
> [ 332.084635] RAX: 0000000000000406 RBX: ffff8d47583e7380 RCX:
> 0000000000000000
> [ 332.085171] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
> 0000000000000000
> [ 332.085699] RBP: 000000000000008f R08: 0000000000000000 R09:
> 0000000000000000
> [ 332.086233] R10: 0000000000000000 R11: 0000000000000000 R12:
> ffff8d47583e7430
> [ 332.086761] R13: ffff8d47583e73c0 R14: 0000000000000406 R15:
> 000495ae650dda58
> [ 332.087300] FS: 00007ff443899980(0000) GS:ffff8df1c5700000(0000)
> knlGS:0000000000000000
> [ 332.087888] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 332.088334] CR2: 000055a42d30b730 CR3: 00000102e956a004 CR4:
> 0000000000770ef0
> [ 332.088867] PKRU: 55555554
> [ 332.089114] Call Trace:
> [ 332.089349] <TASK>
> [ 332.089556] ? die+0x36/0x90
> [ 332.089818] ? do_trap+0xed/0x110
> [ 332.090110] ? exit_mmap+0x3a1/0x3b0
> [ 332.090411] ? do_error_trap+0x6a/0xa0
> [ 332.090722] ? exit_mmap+0x3a1/0x3b0
> [ 332.091029] ? exc_invalid_op+0x50/0x80
> [ 332.091348] ? exit_mmap+0x3a1/0x3b0
> [ 332.091648] ? asm_exc_invalid_op+0x1a/0x20
> [ 332.091998] ? exit_mmap+0x3a1/0x3b0
> [ 332.092299] ? exit_mmap+0x1d6/0x3b0
> [ 332.092604] __mmput+0x3e/0x130
> [ 332.092882] dup_mm.constprop.0+0x10c/0x110
> [ 332.093226] copy_process+0xbd0/0x1570
> [ 332.093539] kernel_clone+0xbf/0x430
> [ 332.093838] ? syscall_exit_work+0x103/0x130
> [ 332.094197] __do_sys_clone+0x66/0xa0
> [ 332.094506] do_syscall_64+0x8c/0x1d0
> [ 332.094814] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.095198] ? audit_reset_context+0x232/0x310
> [ 332.095558] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.095936] ? syscall_exit_work+0x103/0x130
> [ 332.096288] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.096668] ? syscall_exit_to_user_mode+0x7d/0x220
> [ 332.097059] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.097436] ? do_syscall_64+0xba/0x1d0
> [ 332.097752] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.098137] ? syscall_exit_to_user_mode+0x7d/0x220
> [ 332.098525] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.098903] ? do_syscall_64+0xba/0x1d0
> [ 332.099227] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.099606] ? __audit_filter_op+0xbe/0x140
> [ 332.099943] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.100328] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.100706] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.101089] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.101468] ? wp_page_reuse+0x8e/0xb0
> [ 332.101779] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.102163] ? do_wp_page+0xe6/0x470
> [ 332.102465] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.102843] ? __handle_mm_fault+0x5ff/0x720
> [ 332.103197] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.103574] ? __count_memcg_events+0x4d/0xd0
> [ 332.103938] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.104323] ? count_memcg_events.constprop.0+0x26/0x50
> [ 332.104729] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.105114] ? handle_mm_fault+0xae/0x320
> [ 332.105442] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 332.105820] ? do_user_addr_fault+0x31f/0x6c0
> [ 332.106181] entry_SYSCALL_64_after_hwframe+0x76/0x7e
> [ 332.106576] RIP: 0033:0x7ff43f8f9a73
> [ 332.106876] Code: db 0f 85 28 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31
> c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11
> 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 b9 00 00 00 41 89 c5
> 85 c0 0f 85 c6 00 00
> [ 332.108163] RSP: 002b:00007ffc690909b0 EFLAGS: 00000246 ORIG_RAX:
> 0000000000000038
> [ 332.108719] RAX: ffffffffffffffda RBX: 0000000000000000 RCX:
> 00007ff43f8f9a73
> [ 332.109253] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
> 0000000001200011
> [ 332.109782] RBP: 0000000000000000 R08: 0000000000000000 R09:
> 00007ff443899980
> [ 332.110313] R10: 00007ff443899c50 R11: 0000000000000246 R12:
> 0000000000000002
> [ 332.110842] R13: 0000562e56cd4780 R14: 0000000000000006 R15:
> 0000562e800346b0
> [ 332.111381] </TASK>
> [ 332.111590] Modules linked in: rdmaip_notify scsi_transport_iscsi
> target_core_mod rfkill mstflint_access cuse rds$
> rdma rds rdma_ucm rdma_cm iw_cm dm_multipath ib_umad ib_ipoib ib_cm mlx5_ib
> iTCO_wdt iTCO_vendor_support intel_rapl_$
> sr ib_uverbs intel_rapl_common ib_core crc32_pclmul i2c_i801 joydev
> virtio_balloon i2c_smbus lpc_ich binfmt_misc xfs
> sd_mod t10_pi crc64_rocksoft sg crct10dif_pclmul mlx5_core virtio_net ahci
> net_failover mlxfw ghash_clmulni_intel vi$
> tio_scsi failover libahci sha512_ssse3 tls sha256_ssse3 pci_hyperv_intf
> virtio_pci libata psample sha1_ssse3 virtio_$
> ci_legacy_dev serio_raw dimlib virtio_pci_modern_dev qemu_fw_cfg dm_mirror
> dm_region_hash dm_log dm_mod fuse aesni_i$
> tel crypto_simd cryptd
> [ 332.115851] ---[ end trace 0000000000000000 ]---
>
> and another instance splats:
>
> BUG: Bad page map in process PsWatcher.sh pte:9402e1e2b18c8ae9
> pmd:10fe4f067
> [ 193.046098] addr:00007ff912a00000 vm_flags:08000070
> anon_vma:0000000000000000 mapping:ffff8ec28047eeb0 index:200
> [ 193.046863] file:libtinfo.so.6.1 fault:xfs_filemap_fault [xfs]
> mmap:xfs_file_mmap [xfs] read_folio:xfs_vm_read_folio [xfs]
> [ 193.049564] get_swap_device: Bad swap file entry 3803ad7a32eab547
> [ 193.050902] BUG: Bad rss-counter state mm:00000000ff28307a
> type:MM_SWAPENTS val:-1
> [ 193.758147] Kernel panic - not syncing: corrupted stack end detected
> inside scheduler
> [ 193.759151] CPU: 5 PID: 22932 Comm: LogFlusher Tainted: G B
> 6.10.0-rc2+ #1
> [ 193.759764] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
> 1.16.0-4.module+el8.9.0+90173+a3f3e83a 04/01/2014
> [ 193.760435] Call Trace:
> [ 193.760624] <TASK>
> [ 193.760799] panic+0x31d/0x340
> [ 193.761033] __schedule+0xb30/0xb30
> [ 193.761283] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.761605] ? enqueue_hrtimer+0x35/0x90
> [ 193.761883] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.762207] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.762532] ? hrtimer_start_range_ns+0x121/0x300
> [ 193.762856] schedule+0x27/0xb0
> [ 193.763083] futex_wait_queue+0x63/0x90
> [ 193.763354] __futex_wait+0x13d/0x1b0
> [ 193.763610] ? __pfx_futex_wake_mark+0x10/0x10
> [ 193.763918] futex_wait+0x69/0xd0
> [ 193.764153] ? pick_next_task+0x9fb/0xa30
> [ 193.764430] ? __pfx_hrtimer_wakeup+0x10/0x10
> [ 193.764734] do_futex+0x11a/0x1d0
> [ 193.764976] __x64_sys_futex+0x68/0x1c0
> [ 193.765243] do_syscall_64+0x80/0x160
> [ 193.765504] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.765834] ? __audit_filter_op+0xaa/0xf0
> [ 193.766117] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.766437] ? audit_reset_context.part.16+0x270/0x2d0
> [ 193.766895] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.767237] ? syscall_exit_to_user_mode_prepare+0x17b/0x1a0
> [ 193.767624] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.767972] ? syscall_exit_to_user_mode+0x80/0x1e0
> [ 193.768309] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.768628] ? do_syscall_64+0x8c/0x160
> [ 193.768901] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.769225] ? audit_reset_context.part.16+0x270/0x2d0
> [ 193.769573] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.769901] ? restore_fpregs_from_fpstate+0x3c/0xa0
> [ 193.770241] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.770561] ? switch_fpu_return+0x4f/0xd0
> [ 193.770848] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.771171] ? syscall_exit_to_user_mode+0x80/0x1e0
> [ 193.771505] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.771830] ? do_syscall_64+0x8c/0x160
> [ 193.772098] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.772426] ? syscall_exit_to_user_mode_prepare+0x17b/0x1a0
> [ 193.772805] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.773124] ? syscall_exit_to_user_mode+0x80/0x1e0
> [ 193.773458] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.773781] ? do_syscall_64+0x8c/0x160
> [ 193.774047] ? srso_alias_return_thunk+0x5/0xfbef5
> [ 193.774376] ? task_mm_cid_work+0x1c1/0x210
> [ 193.774669] entry_SYSCALL_64_after_hwframe+0x76/0x7e
> [ 193.775010] RIP: 0033:0x7f4da640e898
> [ 193.775270] Code: 24 58 48 85 c0 0f 88 8f 00 00 00 e8 f2 2e 00 00 89 ee
> 4c 8b 54 24 38 31 d2 41 89 c0 40 80 f6 80 4c 89 ef b8 ca 00 00 00 0f 05 <48>
> 3d 00 f0 ff ff 0f 87 ff 00 00 00 44 89 c7 e8 24 2f 00 00 48 8b
> [ 193.776404] RSP: 002b:00007f4d797f2750 EFLAGS: 00000282 ORIG_RAX:
> 00000000000000ca
> [ 193.776893] RAX: ffffffffffffffda RBX: 00007f4d402c1b50 RCX:
> 00007f4da640e898
> [ 193.777355] RDX: 0000000000000000 RSI: 0000000000000080 RDI:
> 00007f4d402c1b7c
> [ 193.777813] RBP: 0000000000000000 R08: 0000000000000000 R09:
> 00007f4da6ece000
> [ 193.778276] R10: 00007f4d797f27a0 R11: 0000000000000282 R12:
> 00007f4d402c1b28
> [ 193.778732] R13: 00007f4d402c1b7c R14: 00007f4d797f2840 R15:
> 0000000000000002
> [ 193.779189] </TASK>
> [ 193.780419] Kernel Offset: 0x13c00000 from 0xffffffff81000000 (relocation
> range: 0xffffffff80000000-0xffffffffbfffffff)
> [ 193.781097] Rebooting in 60 seconds..
>
> Even in premapped mode with use_dma_api, in virtnet_rq_alloc(),
> skb_page_frag_refill() could return order-0 page in honor of disabled high
> order page allocation. Though I still see
>
> alloc_frag->offset += size;
>
> gets accounted irrespective of the actual page size returned (dma->len). And
> virtnet_rq_unmap() seems only cares for high order pages.
>
> Suggest to revert this whole series, or at least the
> virtqueue_set_dma_premapped() should block !use_dma_api user from using the
> virtio DMA APIs.
>
> Regards,
> -Siwei
Want to post a patchset to revert?
>
> On 5/10/2024 8:14 PM, Xuan Zhuo wrote:
> > Now, we have virtio DMA APIs, the driver can be the premapped
> > mode whatever the virtio core uses dma api or not.
> >
> > So remove the limit of checking use_dma_api from
> > virtqueue_set_dma_premapped().
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> > Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
> > ---
> > drivers/virtio/virtio_ring.c | 7 +------
> > 1 file changed, 1 insertion(+), 6 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index 6f7e5010a673..2a972752ff1b 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -2782,7 +2782,7 @@ EXPORT_SYMBOL_GPL(virtqueue_resize);
> > *
> > * Returns zero or a negative error.
> > * 0: success.
> > - * -EINVAL: vring does not use the dma api, so we can not enable premapped mode.
> > + * -EINVAL: too late to enable premapped mode, the vq already contains buffers.
> > */
> > int virtqueue_set_dma_premapped(struct virtqueue *_vq)
> > {
> > @@ -2798,11 +2798,6 @@ int virtqueue_set_dma_premapped(struct virtqueue *_vq)
> > return -EINVAL;
> > }
> > - if (!vq->use_dma_api) {
> > - END_USE(vq);
> > - return -EINVAL;
> > - }
> > -
> > vq->premapped = true;
> > vq->do_unmap = false;
