Patchwork [17/34] pseries: Small cleanup to H_CEDE implementation

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Submitter Alexander Graf
Date Oct. 4, 2012, 1:56 p.m.
Message ID <1349359016-13107-18-git-send-email-agraf@suse.de>
Download mbox | patch
Permalink /patch/189173/
State New
Headers show

Comments

Alexander Graf - Oct. 4, 2012, 1:56 p.m.
From: David Gibson <david@gibson.dropbear.id.au>

The H_CEDE hypercall implementation for the pseries machine doesn't trigger
quite the right path in the main cpu exec loop.  We should set exit_request
to pop up one extra level and recheck state, and we should set the
exception_index to EXCP_HLT (H_CEDE is roughly equivalent to the hlt
instruction on x86).

In practice, this doesn't really matter except for KVM, and KVM implements
H_CEDE internally so we never hit this code path.  But we might as well
get it right, just in case it matters some day.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
 hw/spapr_hcall.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

Patch

diff --git a/hw/spapr_hcall.c b/hw/spapr_hcall.c
index abd847f..2df94d1 100644
--- a/hw/spapr_hcall.c
+++ b/hw/spapr_hcall.c
@@ -544,6 +544,8 @@  static target_ulong h_cede(CPUPPCState *env, sPAPREnvironment *spapr,
     hreg_compute_hflags(env);
     if (!cpu_has_work(env)) {
         env->halted = 1;
+        env->exception_index = EXCP_HLT;
+        env->exit_request = 1;
     }
     return H_SUCCESS;
 }