27/11/06 – woke up at 6 AM again, despite a most enjoyable evening spent at the pub the day before with yrk and 10 Year Old Springbank. Surprised myself and actually went our for a brisk walk and exercise. Spent the rest of the day in various meetings and conference calls, occasionally stealing a few minutes to work on CalIOC2.
If I was going to lca, which I’m not, upon hearing who the first keynote speaker is, I’d request – nay, demand – a dramatic reenactment in person!
26/11/06 – Started the morning with a vigorous 4 KM walk in the neighborhood. I now ache all over, but it was worth it.
Spent a happy few hours with the hardware specs convincing myself the CalIOC2 code is correct. The more I stare at it, the more I’m convinced it’s a hardware bug. The only reason I haven’t thrown it on the hardware guys lap yet is that I was convinced the HW was at fault at least three times during the initial Calgary bringup, and it was a software bug each time, which I eventually figured out by staring at it long enough. So… more staring required.
19/11/06 – dealt with some of the less enjoyable by-products of work such as patent searches for two new disclosures. Also spent some time thinking about the IOMMU performance paper we want to put together for USENIX.
20/11/06 – watched Yael in the morning, then headed into work to listen to a very interesting talk by Yaron Weinsberg on his NIC operating system work. Yaron will also give the talk in Haifa at the lab in a few weeks, ping me if you’re local and would like to attend. Spent the rest of the day in various meetings. Came up with a Pretty Cool Idea in one of them (heresy, I know – a useful meeting?!), now to see if the rest of the team buys into it. Had some hopes that the CalIOC2 machine will come back up after a lab reorg in the evening, but alas, it didn’t happen. Hopefully I’ll be able to get back to the CalIOC2 bringup and the rest of the Xen IOMMU work tomorrow.
13/11 – Avi Kivity visited the lab and gave an ejoyable talk on talk on KVM. From a theoretical POV, I think hypervisors should be small and lean, not based on full-fledged OS kernels. However, from a pragmatic point of view – after dealing with Xen for so long – it’s certainly nice to see the Linux kernel gaining a subset of Xen’s capabilities, while remaining the Linux kernel we know and love.
Spent the rest of the day bringing up the CalIOC2 IOMMU on the Beaverton machine. The bridge issue previously mentioned was pretty easy to solve, we just check if the bus the device is on is a bridge, and if yes, use the IO address space on the bridge’s parent. There was also a nasty issue with the format of an undocumented Calgary/CalIOC2 register initialized by the BIOS which is initialized to the wrong value on CalIOC2. Once that was taken care of, the kernel came up and Calgary worked fine, but DMA’s weren’t going through for the guinea pig PCI-e NIC attached to CalIOC2. Here is my current debug patch calgary-support-calioc2.
14/11 – more CalIOC2 debugging but no discernible progress. Eventually gave up on the flaky machine for the day and moved on to other things. In the evening spent some time talking with various people about plans for next year.
12/1/06 – went to the doctor with the little rascal in the morning and then to breakfast with Orna (we both ate! at the same time! with both hands! if you don’t understand why this is significant, wait until you have a baby…). Dealt with various odds and ends for the rest of the day, but didn’t get any code written. Some days are like this.
Weekend update – taking care of a very fussy yet adorable baby. Who knew babies were this much work? also managed to update my website for the first time in years, including the new index page (does anyone recognize the inspiration?), publications page and new and improved CV. Not that I’m looking, the old one was just shabby.
09/11/06 – took a day off to run necessary errands, but managed to spend a couple of hours at night with the CalIOC2 machine in Beaverton. CalIOC2 is a PCI-e bridge. It looks like the adapters behind the CalIOC2 are actually behind a PCI-to-PCI bridge, which is something the Calgary code doesn’t know how to handle. By the time I’m done with it, it will 🙂
P.S. This is amazing.
07/11/06 – more debugging of Xen in an attempt to perform an elusive and highly non trivial, in fact, downright *unusual*, hypervisor task
– creating a new domain. Eventually, learned to ignore the misleading
tool messages, got the versions of kernel, hypervisor and tools in sync and found out the kernel I was trying to boot can’t work as a domU kernel. D’oh! at this point it was midnight and the baby had worn me out completely so went to sleep.
08/11/06 – woke up and found an email with the calgary-recognize-calioc2 boot log. It wasn’t pretty, we were dying with a NULL pointer dereference in spin_lock_irqsave because of a NULL iommu_table. Quick perusal of the code revealed that I’m a doofus and only handled CalIOC2 in one place rather than the requisite two. Rewrote the patch – leading to a couple of nice cleanups in the old Calgary code – and shipped it off to be tested again.
05/11/06 – Spotted an annoying thinko in the calgary-bios-cleanup patch and sent Andi Kleen a fix. Also looked into hardware for next year’s planned escapades, listened to talk by Stu Feldman (currently IBM VP, but previously the guy who invented make) on Exploratory Research and Services Science, and installed an ssh client on the mobile toy. Hee hee!
06/11/06 – Spent a few frustrating hours trying to get xen-unstable to create a new domain, so that I could give it direct access to a NIC. Failed miserably. Not quite sure what’s wrong yet, except that do_domctl() is returning -1. Probably an incompatibility between the iommu-xenlinux tree and the xen-unstable tools, but more head banging required. Useful tip – always compile the tools with XEN_PYTHON_NATIVE_INSTALL=y if you have more than one python version installed. Also worked on a research proposal for next year on IOMMU performance and listened to Eliot Jaffe’s talk about the Internet Archive’s storage woes.
Muli Ben-Yehuda's journal 