[abdulla]

KVM can take better advantage of hardware acceleration than Xen. Xen requires a modified guest, which traps back to the host more frequently.

[wmf]

Is that true with the newer modes? https://wiki.xen.org/wiki/Understanding_the_Virtualization_S...

[abdulla]

This is based on a cursory examination of [1], so I may be off-base. But Xen appears to rely on the host for many things that can be, and often are, hardware accelerated in KVM. Searching for CONFIG_XEN_PVHVM, it doesn't appear to cover much.

[1] https://github.com/torvalds/linux/blob/master/arch/x86/xen/