JustKernel

Ray Of Hope

June, 2015

multipage support for netback driver + Xen

Here are some of my learnings from my work on multipage support for netback driver. Learnings related to how we are making use of multi page and also how netback and netfron communicate. driver/xen/xen_probe.c keeps monitoring the backend and frontend states and calls the appropriate driver.otherend_changed(drivers/net/netfront or driver/net/netback) function. xenbus.c : static DEFINE_XENBUS_DRIVER(netback, , .probe […]

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Broadwell + Xen + Classic guest kernel + WRITE_FAULT + SMAP Violation.

Recently faced an issue where classic guest kernel (2.6.*) were faulting on Broadwell hardware. From the day 1 doubt was on SMAP feature that is exclusive to Broadwell but had to prove it. Approach: Compiled the guest kernel with instrumentation but can’t use it as the guest on Broadwell hangs just during reboot. (I compiled […]

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Posted in virtualization, Xen | No Comments »