Oh no, you're thinking, yet another cookie pop-up. Well, sorry, it's the law. We measure how many people read us, and ensure you see relevant ads, by storing cookies on your device. If you're cool with that, hit “Accept all Cookies”. For more info and to customize your settings, hit “Customize Settings”.

Review and manage your consent

Here's an overview of our use of cookies, similar technologies and how to manage them. You can also change your choices at any time, by hitting the “Your Consent Options” link on the site's footer.

Manage Cookie Preferences
  • These cookies are strictly necessary so that you can navigate the site as normal and use all features. Without these cookies we cannot provide you with the service that you expect.

  • These cookies are used to make advertising messages more relevant to you. They perform functions like preventing the same ad from continuously reappearing, ensuring that ads are properly displayed for advertisers, and in some cases selecting advertisements that are based on your interests.

  • These cookies collect information in aggregate form to help us understand how our websites are being used. They allow us to count visits and traffic sources so that we can measure and improve the performance of our sites. If people say no to these cookies, we do not know how many people have visited and we cannot monitor performance.

See also our Cookie policy and Privacy policy.

This article is more than 1 year old

Xen 4.11 debuts new ‘PVH’ guest type, for the sake of security

Take some paravirtualization, add hardware extensions and – voila – QEMU flies away

The Xen Project has released version 4.11 of its hypervisor.

As we reported last week, it’s more than a month late, but the projects leaders thinks it is worth the wait because this release delivers on an ambition to “create a cleaner architecture for core technology, less code and a smaller computing base for security and performance.”

A big part of delivering on that is increased use of PVH – a type of virtualization that Xen reckons blends the best of paravirtualization (PV) and Hardware Virtual Machines (HVM). PV virtualizes hardware so a guest can offer kit not found on its host, but doesn’t use virtualization extensions in silicon. HVM can use those extensions and therefore offers each VM isolated emulated hardware.

Xen says its PVH guests “are lightweight HVM guests which use Hardware virtualization support for memory and privileged instructions, PV drivers for I/O and native operating system interfaces for everything else” and reckons that’s the best of both worlds. Oh and they also don’t need QEMU to go about their business, so there’s fewer dependencies to worry about.

Xen likes PVH so much it’s added an experimental version of PVH Dom0 and signalled it will be supported in future releases.

Dom0 is Xen’s host layer, so this shows that Xen is betting pretty big on PVH.

Here’s how the project places PVH guests in the continuum of VM possibilities.

Xen modes

Pick a VM type, any VM type. Source: Xen Wiki. Click to enlarge

Other notables in the new release include lots of speculative execution mitigation, moving PCI configuration space from QEMU to the hypervisor and a pretty substantial re-write of Xen for Arm processors.

Full Xen 4.11 release notes can be found here and downloads are here.

But wait, there’s more! The Xen Project on Monday released Xen 4.7.6, a maintenance release that fixes 21 security issues and 180 other issues. Downloads and changelog are available here. ®

 

Similar topics

TIP US OFF

Send us news


Other stories you might like