On 06/06/2012 02:28 PM, Avi Kivity wrote:
On 06/01/2012 01:20 PM, Paul Mackerras wrote:At the moment we call kvmppc_pin_guest_page() in kvmppc_update_vpa() with two spinlocks held: the vcore lock and the vcpu->vpa_update_lock. This is not good, since kvmppc_pin_guest_page() calls down_read() and get_user_pages_fast(), both of which can sleep. This bug was introduced in 2e25aa5f ("KVM: PPC: Book3S HV: Make virtual processor area registration more robust"). This arranges to drop those spinlocks before calling kvmppc_pin_guest_page() and re-take them afterwards. Dropping the vcore lock in kvmppc_run_core() means we have to set the vcore_state field to VCORE_RUNNING before we drop the lock, so that other vcpus won't try to run this vcore. Signed-off-by: Paul Mackerras<paulus@xxxxxxxxx> --- Since this bug is in Linus' tree, and it can cause a scheduling while atomic bug message, can we send this to Linus for inclusion in 3.5, after review of course?Sure, Alex?
Yup, reviewed and tested. Looks ready to go into the tree to me. Can you pull it in the short way please?
Alex Acked-by: Alexander Graf <agraf@xxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
