Re: [PATCH v3 2/2] hw/cxl: Multi-Region CXL Type-3 Devices (Volatile and Persistent)

From: Gregory Price <gourry.memverge(a)gmail.com&gt; This commit enables each CXL Type-3 device to contain one volatile memory region and one persistent region. Two new properties have been added to cxl-type3 device initialization: [volatile-memdev] and [persistent-memdev] The existing [memdev] property has been deprecated and will default the memory region to a persistent memory region (although a user may assign the region to a ram or file backed region). It cannot be used in combination with the new [persistent-memdev] property. Partitioning volatile memory from persistent memory is not yet supported. Volatile memory is mapped at DPA(0x0), while Persistent memory is mapped at DPA(vmem->size), per CXL Spec 8.2.9.8.2.0 - Get Partition Info. Signed-off-by: Gregory Price <gregory.price(a)memverge.com&gt; Reviewed-by: Davidlohr Bueso <dave(a)stgolabs.net&gt; Reviewed-by: Fan Ni <fan.ni(a)samsung.com&gt; Tested-by: Fan Ni <fan.ni(a)samsung.com&gt; Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com&gt; --- v3: - Don't set the DVSEC range register base address v2: - Fixed an off by one in address space selection. - Gather tags. --- docs/system/devices/cxl.rst | 49 ++++-- hw/cxl/cxl-mailbox-utils.c | 26 +-- hw/mem/cxl_type3.c | 294 +++++++++++++++++++++++++-------- include/hw/cxl/cxl_device.h | 11 +- tests/qtest/bios-tables-test.c | 8 +- tests/qtest/cxl-test.c | 76 +++++++-- 6 files changed, 353 insertions(+), 111 deletions(-) diff --git a/docs/system/devices/cxl.rst b/docs/system/devices/cxl.rst index f25783a4ec..89a41cff73 100644 --- a/docs/system/devices/cxl.rst +++ b/docs/system/devices/cxl.rst @@ -300,7 +300,7 @@ Example topology involving a switch:: Example command lines --------------------- -A very simple setup with just one directly attached CXL Type 3 device:: +A very simple setup with just one directly attached CXL Type 3 Persistent Memory device:: qemu-system-aarch64 -M virt,gic-version=3,cxl=on -m 4g,maxmem=8G,slots=8 -cpu max \ ... @@ -308,7 +308,28 @@ A very simple setup with just one directly attached CXL Type 3 device:: -object memory-backend-file,id=cxl-lsa1,share=on,mem-path=/tmp/lsa.raw,size=256M \ -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \ -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \ - -device cxl-type3,bus=root_port13,memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0 \ + -device cxl-type3,bus=root_port13,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0 \ + -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G + +A very simple setup with just one directly attached CXL Type 3 Volatile Memory device:: + + qemu-system-aarch64 -M virt,gic-version=3,cxl=on -m 4g,maxmem=8G,slots=8 -cpu max \ + ... + -object memory-backend-ram,id=vmem0,share=on,size=256M \ + -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \ + -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \ + -device cxl-type3,bus=root_port13,volatile-memdev=vmem0,id=cxl-vmem0 \ + -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G + +The same volatile setup may optionally include an LSA region:: + + qemu-system-aarch64 -M virt,gic-version=3,cxl=on -m 4g,maxmem=8G,slots=8 -cpu max \ + ... + -object memory-backend-ram,id=vmem0,share=on,size=256M \ + -object memory-backend-file,id=cxl-lsa0,share=on,mem-path=/tmp/lsa.raw,size=256M \ + -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \ + -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \ + -device cxl-type3,bus=root_port13,volatile-memdev=vmem0,lsa=cxl-lsa0,id=cxl-vmem0 \ -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G A setup suitable for 4 way interleave. Only one fixed window provided, to enable 2 way @@ -328,13 +349,13 @@ the CXL Type3 device directly attached (no switches).:: -device pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1 \ -device pxb-cxl,bus_nr=222,bus=pcie.0,id=cxl.2 \ -device cxl-rp,port=0,bus=cxl.1,id=root_port13,chassis=0,slot=2 \ - -device cxl-type3,bus=root_port13,memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0 \ + -device cxl-type3,bus=root_port13,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem0 \ -device cxl-rp,port=1,bus=cxl.1,id=root_port14,chassis=0,slot=3 \ - -device cxl-type3,bus=root_port14,memdev=cxl-mem2,lsa=cxl-lsa2,id=cxl-pmem1 \ + -device cxl-type3,bus=root_port14,persistent-memdev=cxl-mem2,lsa=cxl-lsa2,id=cxl-pmem1 \ -device cxl-rp,port=0,bus=cxl.2,id=root_port15,chassis=0,slot=5 \ - -device cxl-type3,bus=root_port15,memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem2 \ + -device cxl-type3,bus=root_port15,persistent-memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem2 \ -device cxl-rp,port=1,bus=cxl.2,id=root_port16,chassis=0,slot=6 \ - -device cxl-type3,bus=root_port16,memdev=cxl-mem4,lsa=cxl-lsa4,id=cxl-pmem3 \ + -device cxl-type3,bus=root_port16,persistent-memdev=cxl-mem4,lsa=cxl-lsa4,id=cxl-pmem3 \ -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.targets.1=cxl.2,cxl-fmw.0.size=4G,cxl-fmw.0.interleave-granularity=8k An example of 4 devices below a switch suitable for 1, 2 or 4 way interleave:: @@ -354,15 +375,23 @@ An example of 4 devices below a switch suitable for 1, 2 or 4 way interleave:: -device cxl-rp,port=1,bus=cxl.1,id=root_port1,chassis=0,slot=1 \ -device cxl-upstream,bus=root_port0,id=us0 \ -device cxl-downstream,port=0,bus=us0,id=swport0,chassis=0,slot=4 \ - -device cxl-type3,bus=swport0,memdev=cxl-mem0,lsa=cxl-lsa0,id=cxl-pmem0,size=256M \ + -device cxl-type3,bus=swport0,persistent-memdev=cxl-mem0,lsa=cxl-lsa0,id=cxl-pmem0,size=256M \ -device cxl-downstream,port=1,bus=us0,id=swport1,chassis=0,slot=5 \ - -device cxl-type3,bus=swport1,memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem1,size=256M \ + -device cxl-type3,bus=swport1,persistent-memdev=cxl-mem1,lsa=cxl-lsa1,id=cxl-pmem1,size=256M \ -device cxl-downstream,port=2,bus=us0,id=swport2,chassis=0,slot=6 \ - -device cxl-type3,bus=swport2,memdev=cxl-mem2,lsa=cxl-lsa2,id=cxl-pmem2,size=256M \ + -device cxl-type3,bus=swport2,persistent-memdev=cxl-mem2,lsa=cxl-lsa2,id=cxl-pmem2,size=256M \ -device cxl-downstream,port=3,bus=us0,id=swport3,chassis=0,slot=7 \ - -device cxl-type3,bus=swport3,memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem3,size=256M \ + -device cxl-type3,bus=swport3,persistent-memdev=cxl-mem3,lsa=cxl-lsa3,id=cxl-pmem3,size=256M \ -M cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=4G,cxl-fmw.0.interleave-granularity=4k +Deprecations +------------ + +The Type 3 device [memdev] attribute has been deprecated in favor of the +[persistent-memdev] attributes. [memdev] will default to a persistent memory +device for backward compatibility and is incapable of being used in combination +with [persistent-memdev]. +