ARM's lower IPC and frequency may increase the time overhead of pure host-side virtualization or paravirtualization slower, but ARM is also a less convoluted architecture from a system software point of view, and may well have less state to virtualize, so the two may cancel each other out to some extent.
As for other operating systems with ARM support: iOS, several BSDs, RISC OS ( http://www.riscosopen.org/content/downloads ), Haiku ( http://www.haiku-os.org/ ), and all manner of RTOS and other embedded operating systems. Oh, and Windows CE, Windows Embedded Standard, Windows Embedded for Point of Service, Windows Phone 7, etc.
ARM's lower IPC and frequency may increase the time overhead of pure host-side virtualization or paravirtualization slower, but ARM is also a less convoluted architecture from a system software point of view, and may well have less state to virtualize, so the two may cancel each other out to some extent.
As for other operating systems with ARM support: iOS, several BSDs, RISC OS ( http://www.riscosopen.org/content/downloads ), Haiku ( http://www.haiku-os.org/ ), and all manner of RTOS and other embedded operating systems. Oh, and Windows CE, Windows Embedded Standard, Windows Embedded for Point of Service, Windows Phone 7, etc.