On Thu, 2007-07-26 at 18:03 +0300, Avi Kivity wrote: > Gregory Haskins wrote: > > We need to provide locking around the current_vmcs/VMCS interactions to > > protect against race conditions. > > > > > > Can you explain the race?
Sure. It can happen with two VMs are running simultaneously. Lets call them VM-a and VM-b. Assume the scenario: VM-a is on CPU-x, gets migrated to CPU-y, and VM-b gets scheduled in on CPU-x. There is a race on CPU-x with the VMCS handling logic between the VM-b process context, and the IPI to execute the __vcpu_clear for VM-a. Disabling interrupts was chosen as the sync-primitive, because the code will always be on the CPU in question. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
