From 95f87089d1bdd881775a5d09c59363f5460f7ce2 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 14 Jun 2018 01:31:36 +0200 Subject: [PATCH 5/9] spapr_pci: Remove unhelpful pagesize warning RH-Author: David Gibson Message-id: <20180614013136.3504-1-dgibson@redhat.com> Patchwork-id: 80681 O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH] spapr_pci: Remove unhelpful pagesize warning Bugzilla: 1505664 RH-Acked-by: Laurent Vivier RH-Acked-by: Thomas Huth RH-Acked-by: Serhii Popovych From: David Gibson By default, the IOMMU model built into the spapr virtual PCI host bridge supports 4kiB and 64kiB IOMMU page sizes. However this can be overridden which may be desirable to allow larger IOMMU page sizes when running a guest with hugepage backing and passthrough devices. For that reason a warning was printed when the device wasn't configured to allow the pagesize with which guest RAM is backed. Experience has proven, however, that this message is more confusing than useful. Worse it sometimes makes little sense when the host-available page sizes don't match those available on the guest, which can happen with a POWER8 guest running on a POWER9 KVM host. Long term we do want better handling to allow large IOMMU page sizes to be used, but for now this parameter and warning don't really accomplish it. So, remove the message, pending a better solution. Signed-off-by: David Gibson Signed-off-by: David Gibson Signed-off-by: Miroslav Rezanina --- hw/ppc/spapr_pci.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c index 39a1498..f936ce6 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -1717,13 +1717,6 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp) } /* DMA setup */ - if (((sphb->page_size_mask & qemu_getrampagesize()) == 0) - && kvm_enabled()) { - warn_report("System page size 0x%lx is not enabled in page_size_mask " - "(0x%"PRIx64"). Performance may be slow", - qemu_getrampagesize(), sphb->page_size_mask); - } - for (i = 0; i < windows_supported; ++i) { tcet = spapr_tce_new_table(DEVICE(sphb), sphb->dma_liobn[i]); if (!tcet) { -- 1.8.3.1