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<pau...@samba.org>
---
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 <ag...@suse.de>
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