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author | David Gibson <david@gibson.dropbear.id.au> | 2012-08-06 18:44:45 +0000 |
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committer | Alexander Graf <agraf@suse.de> | 2012-08-15 19:43:14 +0200 |
commit | 78e8fde26c032931ca2ae13bfc7c59e38afd17ee (patch) | |
tree | 88ea082231dfe0bcf791b67aa50edf906583f248 /VERSION | |
parent | 4d5c29ca455ed6adb1fb9f8394e4d7badfd0c532 (diff) |
ppc: Fix bug in handling of PAPR hypercall exits
Currently for powerpc, kvm_arch_handle_exit() always returns 1, meaning
that its caller - kvm_cpu_exec() - will always exit immediately afterwards
to the loop in qemu_kvm_cpu_thread_fn().
There's no need to do this. Once we've handled the hypercall there's no
reason we can't go straight around and KVM_RUN again, which is what ret = 0
will signal. The only exception might be for hypercalls which affect the
state of cpu_can_run(), however the only one that might do this is H_CEDE
and for kvm that is always handled in the kernel, not qemu.
Furtherm setting ret = 0 means that when exit_requested is set from a
hypercall, we will enter KVM_RUN once more with a signal which lets the
the kernel do its internal logic to complete the hypercall with out
actually executing any more guest code. This is important if our hypercall
also triggered a reset, which previously would re-initialize everything
without completing the hypercall. This caused the kernel to get confused
because it thought the guest was still in the middle of a hypercall when
it has actually been reset.
This patch therefore changes to ret = 0, which is both a bugfix and a small
optimization.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'VERSION')
0 files changed, 0 insertions, 0 deletions