From: David Gibson Date: Tue, 4 Jul 2017 13:53:55 +0000 (+1000) Subject: spapr: Only report host/guest IOMMU page size mismatches on KVM X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2a0d90fed5b09e27854ac5ca2af836a8248c00c1;p=qemu.git spapr: Only report host/guest IOMMU page size mismatches on KVM We print a warning if the spapr IOMMU isn't configured to support a page size matching the host page size backing RAM. When that's the case we need more complex logic to translate VFIO mappings, which is slower. But, it's not so slow that it would be at all noticeable against the general slowness of TCG. So, only warn when using KVM. This removes some noisy and unhelpful warnings from make check on hosts with page sizes which typically differ from those on POWER (e.g. Sparc). Reported-by: Peter Maydell Signed-off-by: David Gibson Reviewed-by: Thomas Huth --- diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c index cc1588d02b..a52dcf8ec0 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -1745,7 +1745,8 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp) } /* DMA setup */ - if ((sphb->page_size_mask & qemu_getrampagesize()) == 0) { + if (((sphb->page_size_mask & qemu_getrampagesize()) == 0) + && kvm_enabled()) { error_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);