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From 7cce70900ecb644004144c999ee082ff79c0c25e Mon Sep 17 00:00:00 2001
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From: David Gibson <dgibson@redhat.com>
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Date: Thu, 14 Jun 2018 01:31:36 +0200
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Subject: [PATCH 008/268] spapr_pci: Remove unhelpful pagesize warning
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RH-Author: David Gibson <dgibson@redhat.com>
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Message-id: <20180614013136.3504-1-dgibson@redhat.com>
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Patchwork-id: 80681
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O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH] spapr_pci: Remove unhelpful pagesize warning
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Bugzilla: 1505664
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RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
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RH-Acked-by: Thomas Huth <thuth@redhat.com>
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RH-Acked-by: Serhii Popovych <spopovyc@redhat.com>
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From: David Gibson <david@gibson.dropbear.id.au>
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By default, the IOMMU model built into the spapr virtual PCI host bridge
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supports 4kiB and 64kiB IOMMU page sizes.  However this can be overridden
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which may be desirable to allow larger IOMMU page sizes when running a
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guest with hugepage backing and passthrough devices.  For that reason a
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warning was printed when the device wasn't configured to allow the pagesize
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with which guest RAM is backed.
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Experience has proven, however, that this message is more confusing than
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useful.  Worse it sometimes makes little sense when the host-available page
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sizes don't match those available on the guest, which can happen with
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a POWER8 guest running on a POWER9 KVM host.
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Long term we do want better handling to allow large IOMMU page sizes to be
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used, but for now this parameter and warning don't really accomplish it.
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So, remove the message, pending a better solution.
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Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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Signed-off-by: David Gibson <dgibson@redhat.com>
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Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
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---
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 hw/ppc/spapr_pci.c | 7 -------
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 1 file changed, 7 deletions(-)
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diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
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index 39a1498..f936ce6 100644
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--- a/hw/ppc/spapr_pci.c
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+++ b/hw/ppc/spapr_pci.c
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@@ -1717,13 +1717,6 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp)
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     }
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     /* DMA setup */
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-    if (((sphb->page_size_mask & qemu_getrampagesize()) == 0)
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-        && kvm_enabled()) {
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-        warn_report("System page size 0x%lx is not enabled in page_size_mask "
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-                    "(0x%"PRIx64"). Performance may be slow",
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-                    qemu_getrampagesize(), sphb->page_size_mask);
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-    }
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-
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     for (i = 0; i < windows_supported; ++i) {
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         tcet = spapr_tce_new_table(DEVICE(sphb), sphb->dma_liobn[i]);
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         if (!tcet) {
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-- 
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1.8.3.1
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