From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.ru (ozlabs.ru [107.173.13.209]) by lists.ozlabs.org (Postfix) with ESMTP id 3w3Wy10nmkzDqB7 for ; Thu, 13 Apr 2017 17:04:57 +1000 (AEST) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , David Gibson , kvm@vger.kernel.org, Paul Mackerras , kvm-ppc@vger.kernel.org Subject: [PATCH kernel] KVM: PPC: Align the table size to system page size Date: Thu, 13 Apr 2017 17:04:20 +1000 Message-Id: <20170413070420.16927-1-aik@ozlabs.ru> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , At the moment the userspace can request a table smaller than a page size and this value will be stored as kvmppc_spapr_tce_table::size. However the actual allocated size will still be aligned to the system page size as alloc_page() is used there. This aligns the table size up to the system page size. It should not change the existing behaviour but when in-kernel TCE acceleration patchset reaches the upstream kernel, this will allow small TCE tables be accelerated as well: PCI IODA iommu_table allocator already aligns the size and, without this patch, an IOMMU group won't attach to LIOBN due to the mismatching table size. Signed-off-by: Alexey Kardashevskiy --- For sake of bisectability (otherwise in-kernel acceleration won't work hugepages braking DMA completely), this is better be put before [PATCH kernel v11 00/10] powerpc/kvm/vfio: Enable in-kernel acceleration --- arch/powerpc/kvm/book3s_64_vio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index aea3a5b74fb6..45941af9c6d7 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -333,7 +333,7 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, return -EBUSY; } - size = args->size; + size = _ALIGN_UP(args->size, PAGE_SIZE >> 3); npages = kvmppc_tce_pages(size); ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true); if (ret) { -- 2.11.0