Date: Tue, 16 Apr 2019 20:59:10 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 237321] vmx(4) iflib driver fails when number of CPU cores is not a power of two Message-ID: <bug-237321-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=237321 Bug ID: 237321 Summary: vmx(4) iflib driver fails when number of CPU cores is not a power of two Product: Base System Version: 12.0-STABLE Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: ncrogers@gmail.com This is regarding the MFC of r343291 to 12-STABLE in r344027 (Convert vmx(4) to being an iflib driver.) If you configure a VMware ESXi guest with vmxnet3 interfaces and atypical number of CPU cores (e.g 6), the iflib/vmx(4) driver throws an error "device enable command failed" at bootup and periodically when trying to use the interface. This is because , for reasons I do not understand, the driver is unhappy when number of TX/RX queues is not a power of two. Because the driver defaults to 8 queues, whenever a guest boots with 6 cores iflib automatically reduces the number of queues to equal the number of CPU cores. This is resolved by setting the number of tx/rx queues to 1,2, or 4, whichever is less than or equal to the number of CPU cores. For example, on a 6 core system the following works: dev.vmx.0.iflib.override_ntxqs=4 dev.vmx.0.iflib.override_nrxqs=4 I believe either iflib or the vmx driver specifically needs to be corrected to handle an irregular number of queues or limit it to powers of two when there is fewer than 8 cores. Note that this for whatever reason does NOT happen in VMware Fusion under macOS, but seems to always happen in an ESXi environment. In all cases, hw.pci.honor_msi_blacklist is set to 0. -- You are receiving this mail because: You are the assignee for the bug.help
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