Re: [Xen-devel] [PATCH v4 1/7] x86/xpti: avoid copying L4 page table contents when possible

2018-03-28 Thread Jan Beulich
>>> On 27.03.18 at 11:06, wrote: > For mitigation of Meltdown the current L4 page table is copied to the > cpu local root page table each time a 64 bit pv guest is entered. > > Copying can be avoided in cases where the guest L4 page table hasn't > been modified while running the

[Xen-devel] [PATCH v4 1/7] x86/xpti: avoid copying L4 page table contents when possible

2018-03-27 Thread Juergen Gross
For mitigation of Meltdown the current L4 page table is copied to the cpu local root page table each time a 64 bit pv guest is entered. Copying can be avoided in cases where the guest L4 page table hasn't been modified while running the hypervisor, e.g. when handling interrupts or any hypercall