2016-03-09 22:46+0100, Radim Krčmář: > 2016-03-04 14:46-0600, Suravee Suthikulpanit: >> From: Suravee Suthikulpanit <[email protected]> >> >> When a vcpu is loaded/unloaded to a physical core, we need to update >> information in the Physical APIC-ID table accordingly. >> >> Signed-off-by: Suravee Suthikulpanit <[email protected]> >> --- >> +static int avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu, bool is_load) > > This function does a lot and there is only one thing that must be done > in svm_vcpu_load: change host physical APIC ID if the CPU changed. > The rest can be done elsewhere: > - is_running when blocking.
Well, we haven't reached an agreement on is_running yet. The situation: if we don't unset vcpu1.is_running when vcpu1 is scheduled out and vcpu2 gets scheduled on vcpu1's physical core, then vcpu2 would receive a doorbell intended to vcpu1. We'd like to keep is_running set when there is no reason to vmexit, but not if a guest can negatively affect other guests. How does receiving a stray doorbell affect the performance? Thanks. (Toggling is_running on load/put is definitely safer, so it's a good choice for first version.)
