From: renaud@openbsd.org Subject: Re: vio(4): recover from missed RX interrupts in vio_rxtick To: Stefan Fritsch Cc: tech@openbsd.org Date: Fri, 17 Apr 2026 11:16:34 +0200 On Thu, Apr 16, 2026 at 11:16:55PM +0200, Stefan Fritsch wrote: > From: Stefan Fritsch > To: Renaud Allard > cc: tech@openbsd.org > Subject: Re: vio(4): recover from missed RX interrupts in vio_rxtick > Date: Thu, 16 Apr 2026 23:16:55 +0200 (CEST) > > Hi, > > sorry, I missed this mail in February. > > On Sun, 22 Feb 2026, Renaud Allard wrote: > > I've been running an OpenBSD 7.8 VM on Oracle Cloud (arm64, KVM) with a > > I would be interested in a dmesg from this VM with a kernel with > VIRTIO_DEBUG defined to 1. > Here it is: OpenBSD 7.9 (GENERIC) #0: Fri Apr 17 11:01:32 CEST 2026 fuzz@arwen.arnor.org:/home/fuzz/kbuild/sys/arch/arm64/compile/GENERIC real mem = 6436032512 (6137MB) avail mem = 6126092288 (5842MB) random: good seed from bootblocks mainbus0 at root: ACPI psci0 at mainbus0: PSCI 1.0, SMCCC 1.1 efi0 at mainbus0: UEFI 2.7 efi0: EDK II rev 0x10000 smbios0 at efi0: SMBIOS 3.0.0 smbios0: smbios0: QEMU KVM Virtual Machine cpu0 at mainbus0 mpidr 0: ARM Neoverse N1 r3p1 cpu0: 64KB 64b/line 4-way L1 PIPT I-cache, 64KB 64b/line 4-way L1 D-cache cpu0: 1024KB 64b/line 8-way L2 cache cpu0: DP,RDM,Atomic,CRC32,SHA2,SHA1,AES+PMULL,LRCPC,DPB,ASID16,PAN+ATS1E1,LO,HPDS,VH,HAFDBS,CSV3,CSV2,RAS,AdvSIMD+HP,FP+HP,SSBS+MSR apm0 at mainbus0 agintc0 at mainbus0 shift 4:4 nirq 288 nredist 1: "interrupt-controller" agintcmsi0 at agintc0 agtimer0 at mainbus0: 25000 kHz acpi0 at mainbus0: ACPI 6.0 acpi0: sleep states acpi0: tables DSDT FACP APIC GTDT MCFG SPCR DBG2 IORT BGRT acpi0: wakeup devices acpimcfg0 at acpi0 acpimcfg0: addr 0x4010000000, bus 0-255 acpiiort0 at acpi0 acpicpu0 at acpi0 C000 pluart0 at acpi0 COM0 addr 0x9000000/0x1000 irq 33 pluart0: console "LNRO0015" at acpi0 not configured "LNRO0015" at acpi0 not configured "QEMU0002" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured "LNRO0005" at acpi0 not configured acpipci0 at acpi0 PCI0 pci0 at acpipci0 "Red Hat Host" rev 0x00 at pci0 dev 0 function 0 not configured virtio0 at pci0 dev 1 function 0 "Qumranet Virtio 1.x GPU" rev 0x01 virtio_pci_dump_caps: cfgoff 0x84 len 0x14 type 0x5 bar 0: off 0 len 0 virtio_pci_dump_caps: cfgoff 0x70 len 0x14 type 0x2 bar 0x4: off 0x3000 len 0x1000 virtio_pci_dump_caps: cfgoff 0x60 len 0x10 type 0x4 bar 0x4: off 0x2000 len 0x1000 virtio_pci_dump_caps: cfgoff 0x50 len 0x10 type 0x3 bar 0x4: off 0x1000 len 0x1000 virtio_pci_dump_caps: cfgoff 0x40 len 0x10 type 0x1 bar 0x4: off 0 len 0x1000 viogpu0 at virtio0 -EDID +RingIndirectDesc -RingEventIdx +Version1 allocated 8192 byte for virtqueue 0 for control, size 64 allocated 8192 byte for virtqueue 1 for cursor, size 16 virtio0: msix per-VQ viogpu_attach_backing: backing addr 0x43ab0000 length 4096000 : 1280x800, 32bpp wsdisplay0 at viogpu0 mux 1: console (std, vt100 emulation) wsdisplay0: screen 1-5 added (std, vt100 emulation) xhci0 at pci0 dev 2 function 0 "Red Hat xHCI" rev 0x01: msix, xHCI 1.0 usb0 at xhci0: USB revision 3.0 uhub0 at usb0 configuration 1 interface 0 "Red Hat xHCI root hub" rev 3.00/1.00 addr 1 ppb0 at pci0 dev 3 function 0 "Red Hat PCIE" rev 0x00: irq 38 pci1 at ppb0 bus 1 ppb1 at pci0 dev 3 function 1 "Red Hat PCIE" rev 0x00: irq 38 pci2 at ppb1 bus 2 ppb2 at pci0 dev 3 function 2 "Red Hat PCIE" rev 0x00: irq 38 pci3 at ppb2 bus 3 ppb3 at pci0 dev 3 function 3 "Red Hat PCIE" rev 0x00: irq 38 pci4 at ppb3 bus 4 ppb4 at pci0 dev 3 function 4 "Red Hat PCIE" rev 0x00: irq 38 pci5 at ppb4 bus 5 ppb5 at pci0 dev 3 function 5 "Red Hat PCIE" rev 0x00: irq 38 pci6 at ppb5 bus 6 ppb6 at pci0 dev 3 function 6 "Red Hat PCIE" rev 0x00: irq 38 pci7 at ppb6 bus 7 ppb7 at pci0 dev 3 function 7 "Red Hat PCIE" rev 0x00: irq 38 pci8 at ppb7 bus 8 ppb8 at pci0 dev 4 function 0 "Red Hat PCIE" rev 0x00: irq 35 pci9 at ppb8 bus 9 ppb9 at pci0 dev 4 function 1 "Red Hat PCIE" rev 0x00: irq 35 pci10 at ppb9 bus 10 ppb10 at pci0 dev 4 function 2 "Red Hat PCIE" rev 0x00: irq 35 pci11 at ppb10 bus 11 ppb11 at pci0 dev 4 function 3 "Red Hat PCIE" rev 0x00: irq 35 pci12 at ppb11 bus 12 ppb12 at pci0 dev 4 function 4 "Red Hat PCIE" rev 0x00: irq 35 pci13 at ppb12 bus 13 ppb13 at pci0 dev 4 function 5 "Red Hat PCIE" rev 0x00: irq 35 pci14 at ppb13 bus 14 ppb14 at pci0 dev 4 function 6 "Red Hat PCIE" rev 0x00: irq 35 pci15 at ppb14 bus 15 ppb15 at pci0 dev 4 function 7 "Red Hat PCIE" rev 0x00: irq 35 pci16 at ppb15 bus 16 ppb16 at pci0 dev 5 function 0 "Red Hat PCIE" rev 0x00: irq 36 pci17 at ppb16 bus 17 ppb17 at pci0 dev 5 function 1 "Red Hat PCIE" rev 0x00: irq 36 pci18 at ppb17 bus 18 ppb18 at pci0 dev 5 function 2 "Red Hat PCIE" rev 0x00: irq 36 pci19 at ppb18 bus 19 ppb19 at pci0 dev 5 function 3 "Red Hat PCIE" rev 0x00: irq 36 pci20 at ppb19 bus 20 ppb20 at pci0 dev 5 function 4 "Red Hat PCIE" rev 0x00: irq 36 pci21 at ppb20 bus 21 ppb21 at pci0 dev 5 function 5 "Red Hat PCIE" rev 0x00: irq 36 pci22 at ppb21 bus 22 ppb22 at pci0 dev 5 function 6 "Red Hat PCIE" rev 0x00: irq 36 pci23 at ppb22 bus 23 ppb23 at pci0 dev 5 function 7 "Red Hat PCIE" rev 0x00: irq 36 pci24 at ppb23 bus 24 virtio1 at pci24 dev 0 function 0 "Qumranet Virtio 1.x SCSI" rev 0x01 virtio_pci_dump_caps: cfgoff 0xc8 len 0x14 type 0x5 bar 0: off 0 len 0 virtio_pci_dump_caps: cfgoff 0xb4 len 0x14 type 0x2 bar 0x4: off 0x3000 len 0x1000 virtio_pci_dump_caps: cfgoff 0xa4 len 0x10 type 0x4 bar 0x4: off 0x2000 len 0x1000 virtio_pci_dump_caps: cfgoff 0x94 len 0x10 type 0x3 bar 0x4: off 0x1000 len 0x1000 virtio_pci_dump_caps: cfgoff 0x84 len 0x10 type 0x1 bar 0x4: off 0 len 0x1000 virtio_pci_dump_caps: cfgoff 0x7c len 0x3 type 0 bar 0: off 0x1107c09 len 0x4 virtio_pci_dump_caps: cfgoff 0x40 len 0x2 type 0 bar 0: off 0 len 0x411 vioscsi0 at virtio1 allocated 47104 byte for virtqueue 0 for control, size 128 using 38912 byte (2432 entries) indirect descriptors allocated 47104 byte for virtqueue 1 for event, size 128 using 38912 byte (2432 entries) indirect descriptors allocated 47104 byte for virtqueue 2 for request, size 128 using 38912 byte (2432 entries) indirect descriptors : qsize 128 virtio1: msix per-VQ scsibus0 at vioscsi0: 255 targets uk0 at scsibus0 targ 0 lun 0: sd0 at scsibus0 targ 0 lun 1: naa.6051b5d08c7e4bdf864318d1b5f2d1a9 sd0: 47694MB, 512 bytes/sector, 97677312 sectors, thin virtio2 at pci0 dev 6 function 0 "Qumranet Virtio 1.x Network" rev 0x01 virtio_pci_dump_caps: cfgoff 0x84 len 0x14 type 0x5 bar 0: off 0 len 0 virtio_pci_dump_caps: cfgoff 0x70 len 0x14 type 0x2 bar 0x4: off 0x3000 len 0x1000 virtio_pci_dump_caps: cfgoff 0x60 len 0x10 type 0x4 bar 0x4: off 0x2000 len 0x1000 virtio_pci_dump_caps: cfgoff 0x50 len 0x10 type 0x3 bar 0x4: off 0x1000 len 0x1000 virtio_pci_dump_caps: cfgoff 0x40 len 0x10 type 0x1 bar 0x4: off 0 len 0x1000 vio0 at virtio2 +CSum +GuestCSum +CtrlGuestOffl +MAC +GuestTSO4 +GuestTSO6 -GuestECN -GuestUFO +HostTSO4 +HostTSO6 -HostECN -HostUFO +MrgRXBuf +Status +CtrlVQ +CtrlRX -CtrlVLAN -CtrlRXExtra -GuestAnnounce -CtrlMAC +RingIndirectDesc +RingEventIdx +Version1: 1 queue, address 02:00:17:00:93:de allocated 20480 byte for virtqueue 0 for rx, size 256 using 8192 byte (512 entries) indirect descriptors allocated 147456 byte for virtqueue 1 for tx, size 256 using 135168 byte (8448 entries) indirect descriptors 0: q 0xffffff8011209600 rx 0xffffff80112a2800 tx 0xffffff80112a28b0 allocated 8192 byte for virtqueue 2 for control, size 64 virtio2: msix per-VQ acpige0 at acpi0 irq 41 acpibtn0 at acpi0: PWRB uhidev0 at uhub0 port 5 configuration 1 interface 0 "QEMU QEMU USB Tablet" rev 2.00/0.00 addr 2 uhidev0: iclass 3/0 ums0 at uhidev0: 3 buttons, Z dir wsmouse0 at ums0 mux 0 uhidev1 at uhub0 port 6 configuration 1 interface 0 "QEMU QEMU USB Keyboard" rev 2.00/0.00 addr 3 uhidev1: iclass 3/1 ukbd0 at uhidev1: 8 variable keys, 6 key codes wskbd0 at ukbd0 mux 1 wskbd0: connecting to wsdisplay0 uhidev2 at uhub0 port 7 configuration 1 interface 0 "QEMU QEMU USB Mouse" rev 2.00/0.00 addr 4 uhidev2: iclass 3/1 ums1 at uhidev2: 5 buttons, Z dir wsmouse1 at ums1 mux 0 vscsi0 at root scsibus1 at vscsi0: 256 targets softraid0 at root scsibus2 at softraid0: 256 targets root on sd0a (898e7c99458a73ab.a) swap on sd0b dump on sd0b vio_ctrl_rx: cmd 1 0: 0 vio_ctrl_rx: cmd 0 0: 0 vio_ctrl_guest_offloads: offload features 0x182: 0 vio_ctrl_rx: cmd 1 0: 0 vio_ctrl_rx: cmd 0 0: 0