From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 025311A0CC0 for ; Mon, 19 Jan 2015 03:17:35 +1100 (AEDT) Message-ID: <54BBDB6E.6050808@gmx.net> Date: Sun, 18 Jan 2015 17:12:30 +0100 From: Gerhard Pircher MIME-Version: 1.0 To: Alexander Graf Subject: [PATCH] powerpc: kvm: Set M flag for KVM PTE depending on CPU_FTR_NEED_COHERENT Content-Type: text/plain; charset=utf-8 Cc: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Usually page table entries only have the M (coherence) flag set, if the kernel is in SMP mode or to avoid data corruption due to CPU bugs (e.g. some 74xx CPUs). KVM on book3s_32 however always sets the M flag for a PTE, which locks up machines based on the amigaone platform when running QEMU or MoL. Setting the M flag depending on CPU_FTR_NEED_COHERENT also makes KVM work on this platform and aligns the PTE setup to the rest of the kernel. Signed-off-by: Gerhard Pircher --- With this patch I could successfully run a Debian Wheezy installation inside QEMU started with --enable-kvm on my AmigaOneG3SE. arch/powerpc/kvm/book3s_32_mmu_host.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c index 2035d16..935c7d0 100644 --- a/arch/powerpc/kvm/book3s_32_mmu_host.c +++ b/arch/powerpc/kvm/book3s_32_mmu_host.c @@ -204,7 +204,10 @@ next_pteg: pteg0 = ((eaddr & 0x0fffffff) >> 22) | (vsid << 7) | PTE_V | (primary ? 0 : PTE_SEC); - pteg1 = hpaddr | PTE_M | PTE_R | PTE_C; + pteg1 = hpaddr | PTE_R | PTE_C; + + if (cpu_has_feature(CPU_FTR_NEED_COHERENT)) + pteg1 |= PTE_M; if (orig_pte->may_write && writable) { pteg1 |= PP_RWRW; -- 1.9.1