True myths
The appearance of kvm naturally provoked reactions from the competition, which are interesting in the way they imply some untruths while being 100% accurate:kvm is good for desktop -- that is eminently...
View ArticleParavirtualization is dead
Well, not all paravirtualization. I/O device virtualization is certainly the best way to get good I/O performance out of virtual machines, and paravirtualized clocks are still necessary to avoid...
View ArticleMemory overcommit with kvm
kvm supports (or rather, will support; this is work in progress) several ways of running guests with more memory that you have on the host:SwappingThis is the classical way to support overcommit; the...
View ArticleI/O: Maintainability vs Performance
I/O performance is of great importance to a hypervisor. I/O is also a huge maintenance burden, due to the large number of hardware devices that need to be supported, numerous I/O protocols, high...
View ArticleKVM Forum 2008 Agenda posted
The near-final agenda for the KVM Forum 2008 has been posted! I'm pleased to see a well-rounded set of presentations, covering all aspects of kvm development.If you're interested in kvm development,...
View ArticleComparing code size
Starting with Linux 2.6.26, kvm supports four different machine architectures: x86, s390 (System Z, or mainframes), ia64 (Intel's Itanium), and embedded PowerPC processors. It is interesting to compare...
View ArticleHow kvm does security
Like most software, kvm does security in layers.At the inner privilege layer is the kvm module. This code interacts directly with the guest and also has full access to the machine. If breached, a guest...
View ArticleNested svm virtualization for kvm
Yesterday I found a nice surprise in my inbox - a post, by Alex Graf, adding support for virtualizing AMD's SVM instruction set when running KVM on AMD SVM.What does this mean? up until now, when kvm...
View Articlekvm userspace merging into upstream qemu
Recently, Anthony Liguori, one of the qemu maintainers has included kvm support into stock Qemu. This is tremendously important.Why? you might ask. It has to do with how software forks are managed.When...
View ArticleNested vmx support coming to kvm
Almost exactly a year ago I reported on nested svm for kvm - a way to run hypervisors as kvm guests, on AMD hosts. I'm happy to follow up with the corresponding feature for Intel hosts - nested...
View ArticleC, assembly, and security
Let's look at the innocent C statement: a = b + c;What could possible go wrong? Let us list the ways:a, b, or c are the not the variables we wantWe specified addition, but we wanted something elseThe...
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