On Fri, 7 Mar 2025 10:12:57 -0500 Gregory Price <gourry@xxxxxxxxxx> wrote: > On Fri, Mar 07, 2025 at 10:20:31AM +0800, Yuquan Wang wrote: > > > 2a) Is the BIOS programming decoders, or are you programming the > > > decoder after boot? > > Program the decoder after boot. It seems like currently bios for qemu could > > not programm cxl both on x86(q35) and arm64(virt). I am trying to find a > > cxl-enable bios for qemu virt to do some test. > > What's likely happening here then is that QEMU is not emitting an SRAT > (either because the logic is missing or by design). > > From other discussions, this may be the intention of the GenPort work, > which is intended to have placeholders in the SRAT for the Proximity > Domains for devices to be initialized later (i.e. dynamically). > For QEMU you need to provide a whole bunch of config to get SRAT / HMAT etc ( and BIOS never configures the stuff, it's all OS first. I wrote a slightly pathological test case that should give the general idea https://elixir.bootlin.com/qemu/v9.2.2/source/tests/qtest/bios-tables-test.c#L1940 It flushed out a few bugs :) test_acpi_one(" -machine hmat=on,cxl=on" " -smp 3,sockets=3" " -m 128M,maxmem=384M,slots=2" " -device pcie-root-port,chassis=1,id=pci.1" " -device pci-testdev,bus=pci.1," "multifunction=on,addr=00.0" " -device pci-testdev,bus=pci.1,addr=00.1" " -device pci-testdev,bus=pci.1,id=gidev,addr=00.2" " -device pxb-cxl,bus_nr=64,bus=pcie.0,id=cxl.1" " -object memory-backend-ram,size=64M,id=ram0" " -object memory-backend-ram,size=64M,id=ram1" " -numa node,nodeid=0,cpus=0,memdev=ram0" " -numa node,nodeid=1" " -object acpi-generic-initiator,id=gi0,pci-dev=gidev,node=1" " -numa node,nodeid=2" " -object acpi-generic-port,id=gp0,pci-bus=cxl.1,node=2" " -numa node,nodeid=3,cpus=1" " -numa node,nodeid=4,memdev=ram1" " -numa node,nodeid=5,cpus=2" " -numa hmat-lb,initiator=0,target=0,hierarchy=memory," "data-type=access-latency,latency=10" " -numa hmat-lb,initiator=0,target=0,hierarchy=memory," "data-type=access-bandwidth,bandwidth=800M" " -numa hmat-lb,initiator=0,target=2,hierarchy=memory," "data-type=access-latency,latency=100" " -numa hmat-lb,initiator=0,target=2,hierarchy=memory," "data-type=access-bandwidth,bandwidth=200M" " -numa hmat-lb,initiator=0,target=4,hierarchy=memory," "data-type=access-latency,latency=100" " -numa hmat-lb,initiator=0,target=4,hierarchy=memory," "data-type=access-bandwidth,bandwidth=200M" " -numa hmat-lb,initiator=0,target=5,hierarchy=memory," "data-type=access-latency,latency=200" " -numa hmat-lb,initiator=0,target=5,hierarchy=memory," "data-type=access-bandwidth,bandwidth=400M" " -numa hmat-lb,initiator=1,target=0,hierarchy=memory," "data-type=access-latency,latency=500" " -numa hmat-lb,initiator=1,target=0,hierarchy=memory," "data-type=access-bandwidth,bandwidth=100M" " -numa hmat-lb,initiator=1,target=2,hierarchy=memory," "data-type=access-latency,latency=50" " -numa hmat-lb,initiator=1,target=2,hierarchy=memory," "data-type=access-bandwidth,bandwidth=400M" " -numa hmat-lb,initiator=1,target=4,hierarchy=memory," "data-type=access-latency,latency=50" " -numa hmat-lb,initiator=1,target=4,hierarchy=memory," "data-type=access-bandwidth,bandwidth=800M" " -numa hmat-lb,initiator=1,target=5,hierarchy=memory," "data-type=access-latency,latency=500" " -numa hmat-lb,initiator=1,target=5,hierarchy=memory," "data-type=access-bandwidth,bandwidth=100M" " -numa hmat-lb,initiator=3,target=0,hierarchy=memory," "data-type=access-latency,latency=20" " -numa hmat-lb,initiator=3,target=0,hierarchy=memory," "data-type=access-bandwidth,bandwidth=400M" " -numa hmat-lb,initiator=3,target=2,hierarchy=memory," "data-type=access-latency,latency=80" " -numa hmat-lb,initiator=3,target=2,hierarchy=memory," "data-type=access-bandwidth,bandwidth=200M" " -numa hmat-lb,initiator=3,target=4,hierarchy=memory," "data-type=access-latency,latency=80" " -numa hmat-lb,initiator=3,target=4,hierarchy=memory," "data-type=access-bandwidth,bandwidth=200M" " -numa hmat-lb,initiator=3,target=5,hierarchy=memory," "data-type=access-latency,latency=20" " -numa hmat-lb,initiator=3,target=5,hierarchy=memory," "data-type=access-bandwidth,bandwidth=400M" " -numa hmat-lb,initiator=5,target=0,hierarchy=memory," "data-type=access-latency,latency=20" " -numa hmat-lb,initiator=5,target=0,hierarchy=memory," "data-type=access-bandwidth,bandwidth=400M" " -numa hmat-lb,initiator=5,target=2,hierarchy=memory," "data-type=access-latency,latency=80" " -numa hmat-lb,initiator=5,target=4,hierarchy=memory," "data-type=access-bandwidth,bandwidth=200M" " -numa hmat-lb,initiator=5,target=4,hierarchy=memory," "data-type=access-latency,latency=80" " -numa hmat-lb,initiator=5,target=2,hierarchy=memory," "data-type=access-bandwidth,bandwidth=200M" " -numa hmat-lb,initiator=5,target=5,hierarchy=memory," "data-type=access-latency,latency=10" " -numa hmat-lb,initiator=5,target=5,hierarchy=memory," "data-type=access-bandwidth,bandwidth=800M", &data); Jonathan > ~Gregory >
