On Fri, Mar 11, 2016 at 12:47 PM, David Matlack <dmatl...@google.com> wrote: > From: Eric Northup <digitale...@google.com> > > Add a percpu boolean, tracking whether a KVM vCPU is running on the > host CPU. KVM will set and clear it as it loads/unloads guest XCR0. > (Note that the rest of the guest FPU load/restore is safe, because > kvm_load_guest_fpu and kvm_put_guest_fpu call __kernel_fpu_begin() > and __kernel_fpu_end(), respectively.) irq_fpu_usable() will then > also check for this percpu boolean.
Is this better than just always keeping the host's XCR0 loaded outside if the KVM interrupts-disabled region? --Andy
