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author | Greg Kurz <gkurz@linux.vnet.ibm.com> | 2016-01-15 16:00:12 +0100 |
---|---|---|
committer | David Gibson <david@gibson.dropbear.id.au> | 2016-01-30 23:37:37 +1100 |
commit | 3a4b791b4c13e02537a5cc572fa3de70bc5f68da (patch) | |
tree | 49d8aaa7e9e11336797511fd4b1a4545c71ce197 | |
parent | 98a5d100c2dfcc2b6daefd8c176eb34055e5b38d (diff) | |
download | qemu-3a4b791b4c13e02537a5cc572fa3de70bc5f68da.tar.gz |
target-ppc: kvm: fix floating point registers sync on little-endian hosts
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 <gkurz@linux.vnet.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
-rw-r--r-- | target-ppc/kvm.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c index c2e8912745..60ff119488 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 } } } |