From 96dbc9af35eb6672a3b531da8bba521ce46c26dc Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Mon, 11 Sep 2017 12:14:19 +0200 Subject: [PATCH] spapr_pci: don't create 64-bit MMIO window if we don't need to When running a pseries-2.2 or older machine type, we get the following lines in info mtree: address-space: memory ... ffffffffffffffff-ffffffffffffffff (prio 0, i/o): alias pci@800000020000000.mmio64-alias @pci@800000020000000.mmio ffffffffffffffff-ffffffffffffffff address-space: cpu-memory ... ffffffffffffffff-ffffffffffffffff (prio 0, i/o): alias pci@800000020000000.mmio64-alias @pci@800000020000000.mmio ffffffffffffffff-ffffffffffffffff The same thing occurs when running a pseries-2.7 with -global spapr-pci-host-bridge.mem_win_size=2147483648 This happens because we always create a 64-bit MMIO window, even if we didn't explicitely requested it (ie, mem64_win_size == 0) and the 32-bit window is below 2GiB. It doesn't seem to have an impact on the guest though because spapr_populate_pci_dt() doesn't advertise the bogus windows when mem64_win_size == 0. Since these memory regions don't induce any state, we can safely choose to not create them when their address is equal to -1, without breaking migration from existing setups. Signed-off-by: Greg Kurz Signed-off-by: David Gibson --- hw/ppc/spapr_pci.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c index 7d84b9766e..cf54160526 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -1622,13 +1622,19 @@ static void spapr_phb_realize(DeviceState *dev, Error **errp) memory_region_add_subregion(get_system_memory(), sphb->mem_win_addr, &sphb->mem32window); - namebuf = g_strdup_printf("%s.mmio64-alias", sphb->dtbusname); - memory_region_init_alias(&sphb->mem64window, OBJECT(sphb), - namebuf, &sphb->memspace, - sphb->mem64_win_pciaddr, sphb->mem64_win_size); - g_free(namebuf); - memory_region_add_subregion(get_system_memory(), sphb->mem64_win_addr, - &sphb->mem64window); + if (sphb->mem64_win_pciaddr != (hwaddr)-1) { + namebuf = g_strdup_printf("%s.mmio64-alias", sphb->dtbusname); + memory_region_init_alias(&sphb->mem64window, OBJECT(sphb), + namebuf, &sphb->memspace, + sphb->mem64_win_pciaddr, sphb->mem64_win_size); + g_free(namebuf); + + if (sphb->mem64_win_addr != (hwaddr)-1) { + memory_region_add_subregion(get_system_memory(), + sphb->mem64_win_addr, + &sphb->mem64window); + } + } /* Initialize IO regions */ namebuf = g_strdup_printf("%s.io", sphb->dtbusname); -- 2.11.4.GIT