From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52792) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ai3f7-0004F5-62 for qemu-devel@nongnu.org; Mon, 21 Mar 2016 13:30:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ai3f3-0001ou-SM for qemu-devel@nongnu.org; Mon, 21 Mar 2016 13:30:41 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:47992) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ai3f3-0001o5-Jx for qemu-devel@nongnu.org; Mon, 21 Mar 2016 13:30:37 -0400 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 21 Mar 2016 11:30:36 -0600 From: Michael Roth Date: Mon, 21 Mar 2016 12:28:01 -0500 Message-Id: <1458581313-19045-4-git-send-email-mdroth@linux.vnet.ibm.com> In-Reply-To: <1458581313-19045-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1458581313-19045-1-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 03/35] target-ppc: kvm: fix floating point registers sync on little-endian hosts List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Michael Roth , David Gibson , qemu-stable@nongnu.org, Greg Kurz From: Greg Kurz 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 Signed-off-by: David Gibson (cherry picked from commit 3a4b791b4c13e02537a5cc572fa3de70bc5f68da) Signed-off-by: Michael Roth --- 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