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[Qemu-stable] [PATCH 03/35] target-ppc: kvm: fix floating point register
From: |
Michael Roth |
Subject: |
[Qemu-stable] [PATCH 03/35] target-ppc: kvm: fix floating point registers sync on little-endian hosts |
Date: |
Mon, 21 Mar 2016 12:28:01 -0500 |
From: Greg Kurz <address@hidden>
On VSX capable CPUs, the 32 FP registers are mapped to the high-bits
of the 32 first VSX registers. So if you have:
VSR31 = (uint128) 0x0102030405060708090a0b0c0d0e0f00
then
FPR31 = (uint64) 0x0102030405060708
The kernel stores the VSX registers in the fp_state struct following the
host endian element ordering.
On big-endian:
fp_state.fpr[31][0] = 0x0102030405060708
fp_state.fpr[31][1] = 0x090a0b0c0d0e0f00
On little-endian:
fp_state.fpr[31][0] = 0x090a0b0c0d0e0f00
fp_state.fpr[31][1] = 0x0102030405060708
The KVM_GET_ONE_REG and KVM_SET_ONE_REG ioctls preserve this ordering, but
QEMU considers it as big-endian and always copies element [0] to the
fpr[] array and element [1] to the vsr[] array. This does not work with
little-endian hosts, and you will get:
(qemu) p $f31
0x90a0b0c0d0e0f00
instead of:
(qemu) p $f31
0x102030405060708
This patch fixes the element ordering for little-endian hosts.
Signed-off-by: Greg Kurz <address@hidden>
Signed-off-by: David Gibson <address@hidden>
(cherry picked from commit 3a4b791b4c13e02537a5cc572fa3de70bc5f68da)
Signed-off-by: Michael Roth <address@hidden>
---
target-ppc/kvm.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index ac70f08..acd3275 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -650,8 +650,13 @@ static int kvm_put_fp(CPUState *cs)
for (i = 0; i < 32; i++) {
uint64_t vsr[2];
+#ifdef HOST_WORDS_BIGENDIAN
vsr[0] = float64_val(env->fpr[i]);
vsr[1] = env->vsr[i];
+#else
+ vsr[0] = env->vsr[i];
+ vsr[1] = float64_val(env->fpr[i]);
+#endif
reg.addr = (uintptr_t) &vsr;
reg.id = vsx ? KVM_REG_PPC_VSR(i) : KVM_REG_PPC_FPR(i);
@@ -721,10 +726,17 @@ static int kvm_get_fp(CPUState *cs)
vsx ? "VSR" : "FPR", i, strerror(errno));
return ret;
} else {
+#ifdef HOST_WORDS_BIGENDIAN
env->fpr[i] = vsr[0];
if (vsx) {
env->vsr[i] = vsr[1];
}
+#else
+ env->fpr[i] = vsr[1];
+ if (vsx) {
+ env->vsr[i] = vsr[0];
+ }
+#endif
}
}
}
--
1.9.1
- Re: [Qemu-stable] [PATCH 28/35] spapr: skip configuration section during migration of older machines, (continued)
[Qemu-stable] [PATCH 02/35] net: vmxnet3: avoid memory leakage in activate_device, Michael Roth, 2016/03/21
[Qemu-stable] [PATCH 04/35] configure: Fix shell syntax to placate OpenBSD's pdksh, Michael Roth, 2016/03/21
[Qemu-stable] [PATCH 05/35] xen/blkif: Avoid double access to src->nr_segments, Michael Roth, 2016/03/21
[Qemu-stable] [PATCH 08/35] scsi: initialise info object with appropriate size, Michael Roth, 2016/03/21
[Qemu-stable] [PATCH 07/35] virtio-9p: use accessor to get thread_pool, Michael Roth, 2016/03/21
[Qemu-stable] [PATCH 06/35] xenfb: avoid reading twice the same fields from the shared page, Michael Roth, 2016/03/21
[Qemu-stable] [PATCH 35/35] vl.c: Fix regression in machine error message, Michael Roth, 2016/03/21
[Qemu-stable] [PATCH 03/35] target-ppc: kvm: fix floating point registers sync on little-endian hosts,
Michael Roth <=
Re: [Qemu-stable] [PATCH 00/35] Patch Round-up for stable 2.5.1, freeze on 2016-03-25, Cole Robinson, 2016/03/21
Re: [Qemu-stable] [PATCH 00/35] Patch Round-up for stable 2.5.1, freeze on 2016-03-25, Peter Lieven, 2016/03/22