From ede24a026411c260b5471348f431ec2f3c5e8f2b Mon Sep 17 00:00:00 2001 From: Ladi Prosek Date: Thu, 25 May 2017 09:07:47 +0200 Subject: [PATCH] pc: ACPI BIOS: use highest NUMA node for hotplug mem hole SRAT entry For reasons unknown, Windows won't online all memory, both at command line and hot-plugged later, unless the hotplug mem hole SRAT entry specifies a node greater than or equal to the ones where memory is added. Using the highest node on the machine makes recent versions of Windows happy. With this example command line: ... \ -m 1024,slots=4,maxmem=32G \ -numa node,nodeid=0 \ -numa node,nodeid=1 \ -numa node,nodeid=2 \ -numa node,nodeid=3 \ -object memory-backend-ram,size=1G,id=mem-mem1 \ -device pc-dimm,id=dimm-mem1,memdev=mem-mem1,node=1 Windows reports a total of 1G of RAM without this commit and the expected 2G with this commit. Signed-off-by: Ladi Prosek Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Igor Mammedov Acked-by: Laszlo Ersek --- hw/i386/acpi-build.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index afcadacd2e..82bd44f38e 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -2404,14 +2404,17 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine) } /* - * Entry is required for Windows to enable memory hotplug in OS. + * Entry is required for Windows to enable memory hotplug in OS + * and for Linux to enable SWIOTLB when booted with less than + * 4G of RAM. Windows works better if the entry sets proximity + * to the highest NUMA node in the machine. * Memory devices may override proximity set by this entry, * providing _PXM method if necessary. */ if (hotplugabble_address_space_size) { numamem = acpi_data_push(table_data, sizeof *numamem); build_srat_memory(numamem, pcms->hotplug_memory.base, - hotplugabble_address_space_size, 0, + hotplugabble_address_space_size, pcms->numa_nodes - 1, MEM_AFFINITY_HOTPLUGGABLE | MEM_AFFINITY_ENABLED); }