Messages in this thread | | | Subject | Re: [PATCH v3 2/5] KVM: add KVM_REQ_EXIT request for userspace exit | From | Paolo Bonzini <> | Date | Sat, 22 Aug 2015 00:04:55 -0700 |
| |
On 19/08/2015 20:55, Wanpeng Li wrote: >> The disadvantage is that it adds an overhead of one bit check for all >> kernel exits. A quick tracing shows that the ratio of userspace exits >> after boot is about 1/5 and in subsequent run of nmap and kernel compile >> has about 1/60, so the check should not regress global performance. >> >> All signal_pending() calls are userspace exit requests, so we add a >> check for KVM_REQ_EXIT there. There is one omitted call in kvm_vcpu_run >> because KVM_REQ_EXIT is implied in earlier check for requests. > > Actually I see more SIGUSR1 signals are intercepted by signal_pending() > in vcpu_enter_guest() and vcpu_run() w/ win7 guest and kernel_irqchip=off.
You need more patches on the QEMU side. I tested a version that is mostly okay but not ready for upstream inclusion.
Paolo
| |