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[Qemu-devel] [PATCH 03/23] ppc: Fix bug in handling of PAPR hypercall ex
From: |
Michael Roth |
Subject: |
[Qemu-devel] [PATCH 03/23] ppc: Fix bug in handling of PAPR hypercall exits |
Date: |
Tue, 21 Aug 2012 12:05:37 -0500 |
From: David Gibson <address@hidden>
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 <address@hidden>
Signed-off-by: Alexander Graf <address@hidden>
(cherry picked from commit 78e8fde26c032931ca2ae13bfc7c59e38afd17ee)
Signed-off-by: Michael Roth <address@hidden>
---
target-ppc/kvm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index c09cc39..29997af 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:
--
1.7.9.5
- [Qemu-devel] [stable-1.1] Patch Round-up for stable 1.1.2, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 02/23] configure: Don't override user's --cpu on MacOS and Solaris, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 03/23] ppc: Fix bug in handling of PAPR hypercall exits,
Michael Roth <=
- [Qemu-devel] [PATCH 05/23] kvmvapic: Disable if there is insufficient memory, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 04/23] s390: Fix error handling and condition code of service call, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 01/23] qtest: fix infinite loop when QEMU aborts abruptly, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 07/23] virtio-blk: fix use-after-free while handling scsi commands, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 08/23] ehci: fix reset, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 06/23] qdev: fix use-after-free in the error path of qdev_init_nofail, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 13/23] usb-ehci: Fix an assert whenever isoc transfers are used, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 11/23] usb: restore USBDevice->attached on vmload, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 10/23] uhci: fix uhci_async_cancel_all, Michael Roth, 2012/08/21
- [Qemu-devel] [PATCH 14/23] qlist: add qlist_size(), Michael Roth, 2012/08/21