From 6ef9f439f68181319e04b5fd6bfb1a2e36d4bbee Mon Sep 17 00:00:00 2001 From: David Gibson Date: Mon, 18 Sep 2017 00:20:08 +0100 Subject: vfio, spapr: Fix levels calculation RH-Author: David Gibson Message-id: <20170918002008.24430-1-dgibson@redhat.com> Patchwork-id: 76404 O-Subject: [Pegas-1.0 qemu-kvm PATCH] vfio, spapr: Fix levels calculation Bugzilla: 1491749 RH-Acked-by: Laurent Vivier RH-Acked-by: Suraj Jitindar Singh RH-Acked-by: Sam Bobroff From: Alexey Kardashevskiy The existing tries to round up the number of pages but @pages is always calculated as the rounded up value minus one which makes ctz64() always return 0 and have create.levels always set 1. This removes wrong "-1" and allows having more than 1 levels. This becomes handy for >128GB guests with standard 64K pages as this requires blocks with zone order 9 and the popular limit of CONFIG_FORCE_MAX_ZONEORDER=9 means that only blocks up to order 8 are allowed. Signed-off-by: Alexey Kardashevskiy Signed-off-by: David Gibson (cherry picked from commit e100161b69f8cf56dae866912dfffe7dcd7140af) Signed-off-by: David Gibson Signed-off-by: Danilo C. L. de Paula (cherry picked from commit b83a6ae1492fa004c6e0e34cfb3ac8efe21e7bd2) --- hw/vfio/spapr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/vfio/spapr.c b/hw/vfio/spapr.c index 32fd6a9..259397c 100644 --- a/hw/vfio/spapr.c +++ b/hw/vfio/spapr.c @@ -163,7 +163,7 @@ int vfio_spapr_create_window(VFIOContainer *container, */ entries = create.window_size >> create.page_shift; pages = MAX((entries * sizeof(uint64_t)) / getpagesize(), 1); - pages = MAX(pow2ceil(pages) - 1, 1); /* Round up */ + pages = MAX(pow2ceil(pages), 1); /* Round up */ create.levels = ctz64(pages) / 6 + 1; ret = ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &create); -- 1.8.3.1