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[Qemu-devel] [PATCH 07/24] ppc: Fix bug in handling of PAPR hypercall ex
From: |
Alexander Graf |
Subject: |
[Qemu-devel] [PATCH 07/24] ppc: Fix bug in handling of PAPR hypercall exits |
Date: |
Wed, 15 Aug 2012 11:58:45 +0200 |
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>
---
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 829e180..a31d278 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -766,7 +766,7 @@ 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:
--
1.6.0.2
- [Qemu-devel] [PULL 00/24] ppc patch queue 2012-08-15, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 03/24] PPC: e500: rename mpc8544ds into generic file, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 02/24] pseries pci: spapr_populate_pci_devices renamed to spapr_populate_pci_dt, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 04/24] PPC: e500: change internal references away from mpc8544ds, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 01/24] pseries pci: removed redundant busdev, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 05/24] PPC: e500: split mpc8544ds machine from generic e500 code, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 06/24] PPC: e500: add generic e500 platform, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 07/24] ppc: Fix bug in handling of PAPR hypercall exits,
Alexander Graf <=
- [Qemu-devel] [PATCH 08/24] Revert "PPC: e500: Use new MPIC dt format", Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 11/24] xbzrle: fix compilation on ppc32, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 09/24] Add one new file vga-pci.h and cleanup on all platforms, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 13/24] PPC: spapr: Remove global variable, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 10/24] spapr: Add support for -vga option, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 12/24] PPC: spapr: Rework VGA select logic, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 15/24] pseries: Remove extraneous prints, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 19/24] pseries: Export find_phb() utility function for PCI code, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 17/24] pseries: Separate PCI RTAS setup from common from emulation specific PCI setup, Alexander Graf, 2012/08/15
- [Qemu-devel] [PATCH 16/24] pseries: Rework irq assignment to avoid carrying qemu_irqs around, Alexander Graf, 2012/08/15