diff options
author | David Gibson <david@gibson.dropbear.id.au> | 2012-08-06 18:44:45 +0000 |
---|---|---|
committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2012-08-21 15:36:34 -0500 |
commit | 08e642c00e979b10e3fb293272dc3057ab9f220b (patch) | |
tree | 2b8ec0445f22c59949958320f014333b3595605e | |
parent | 7940c766d470ddb184f6d678d080006d2b668172 (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>
(cherry picked from commit 78e8fde26c032931ca2ae13bfc7c59e38afd17ee)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
-rw-r--r-- | target-ppc/kvm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index c09cc39c7..29997af76 100644 --- a/target-ppc/kvm.c +++ b/target-ppc/kvm.c @@ -558,7 +558,7 @@ int kvm_arch_handle_exit(CPUPPCState *env, struct kvm_run *run) dprintf("handle PAPR hypercall\n"); run->papr_hcall.ret = spapr_hypercall(env, run->papr_hcall.nr, run->papr_hcall.args); - ret = 1; + ret = 0; break; #endif default: |