Date: Wed, 09 Jul 2025 14:47:53 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 288122] msi_map: unsupported destination APIC ID 257 Message-ID: <bug-288122-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=288122 Bug ID: 288122 Summary: msi_map: unsupported destination APIC ID 257 Product: Base System Version: 14.3-RELEASE Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: dwmw2@infradead.org I've downloaded FreeBSD-14.3-RELEASE-amd64.qcow2 and I'm running it in qemu under Linux/KVM to test how well it supports having lots of vCPUs (specifically those with APIC IDs > 255). (This might be a good moment to review http://david.woodhou.se/more-than-you-ever-wanted-to-know-about-x86-msis.txt if needed) My QEMU command line looks a bit like this... qemu-system-x86_64 -accel kvm,kernel-irqchip=split \ -drive file=~/FreeBSD-14.3-RELEASE-amd64.qcow2,id=nvm,if=none,snapshot=on \ -device nvme,drive=nvm,serial=1 -m 16G -M q35 \ -accel kvm,kernel-irqchip=split \ -usb -device usb-mouse -device usb-kbd -device usb-tablet \ -smp 1,maxcpus=288,sockets=8 -device host-x86_64-cpu,apic-id=257 \ -cpu host -serial mon:stdio \ -device amd-iommu,intremap=on,xtsup=on So it should have two CPUs, with APIC IDs 0 and 0x101. And it does... > cpu0 BSP: > ID: 0x00000000 VER: 0x01050014 LDR: 0x00000001 DFR: 0x00000000 x2APIC: 1 > lint0: 0x00010700 lint1: 0x00000400 TPR: 0x00000000 SVR: 0x000001ff > timer: 0x000300ef therm: 0x00010000 err: 0x000000f0 pmc: 0x00010400 > SMP: AP CPU #1 Launched! > cpu1 AP: > ID: 0x00000101 VER: 0x01050014 LDR: 0x00100002 DFR: 0x00000000 x2APIC: 1 > lint0: 0x00010700 lint1: 0x00000400 TPR: 0x00000000 SVR: 0x000001ff > timer: 0x000100ef therm: 0x00010000 err: 0x000000f0 pmc: 0x00010400 But it only routes interrupts to CPU0, it seems... > nvme0: <Generic NVMe Device> mem 0x380000000000-0x380000003fff irq 23 at device 3.0 on pci0 > nvme0: attempting to allocate 3 MSI-X vectors (65 supported) > msi: routing MSI-X IRQ 26 to local APIC 0 vector 52 > msi: routing MSI-X IRQ 27 to local APIC 0 vector 53 > msi: routing MSI-X IRQ 28 to local APIC 0 vector 54 FWIW it does say this too, and the 'no driver attached' part is noteworthy. > pci0: <base peripheral, IOMMU> at device 4.0 (no driver attached) But that shouldn't matter anyway because you don't *need* an IOMMU, KVM is advertising that MSIs support 15 bits of APIC ID. -- You are receiving this mail because: You are the assignee for the bug.home | help
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