qemu-e2k/hw/cxl/cxl-host-stubs.c

/*
 * CXL host parameter parsing routine stubs
 *
 * Copyright (c) 2022 Huawei
 */
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/cxl/cxl.h"
#include "hw/cxl/cxl_host.h"

void cxl_fmws_link_targets(CXLState *stat, Error **errp) {};
void cxl_machine_init(Object *obj, CXLState *state) {};
void cxl_hook_up_pxb_registers(PCIBus *bus, CXLState *state, Error **errp) {};

const MemoryRegionOps cfmws_ops;
hw/cxl/host: Add support for CXL Fixed Memory Windows. The concept of these is introduced in [1] in terms of the description the CEDT ACPI table. The principal is more general. Unlike once traffic hits the CXL root bridges, the host system memory address routing is implementation defined and effectively static once observable by standard / generic system software. Each CXL Fixed Memory Windows (CFMW) is a region of PA space which has fixed system dependent routing configured so that accesses can be routed to the CXL devices below a set of target root bridges. The accesses may be interleaved across multiple root bridges. For QEMU we could have fully specified these regions in terms of a base PA + size, but as the absolute address does not matter it is simpler to let individual platforms place the memory regions. ExampleS: -cxl-fixed-memory-window targets.0=cxl.0,size=128G -cxl-fixed-memory-window targets.0=cxl.1,size=128G -cxl-fixed-memory-window targets.0=cxl0,targets.1=cxl.1,size=256G,interleave-granularity=2k Specifies * 2x 128G regions not interleaved across root bridges, one for each of the root bridges with ids cxl.0 and cxl.1 * 256G region interleaved across root bridges with ids cxl.0 and cxl.1 with a 2k interleave granularity. When system software enumerates the devices below a given root bridge it can then decide which CFMW to use. If non interleave is desired (or possible) it can use the appropriate CFMW for the root bridge in question. If there are suitable devices to interleave across the two root bridges then it may use the 3rd CFMS. A number of other designs were considered but the following constraints made it hard to adapt existing QEMU approaches to this particular problem. 1) The size must be known before a specific architecture / board brings up it's PA memory map. We need to set up an appropriate region. 2) Using links to the host bridges provides a clean command line interface but these links cannot be established until command line devices have been added. Hence the two step process used here of first establishing the size, interleave-ways and granularity + caching the ids of the host bridges and then, once available finding the actual host bridges so they can be used later to support interleave decoding. [1] CXL 2.0 ECN: CEDT CFMWS & QTG DSM (computeexpresslink.org / specifications) Signed-off-by: Jonathan Cameron <jonathan.cameron@huawei.com> Acked-by: Markus Armbruster <armbru@redhat.com> # QAPI Schema Message-Id: <20220429144110.25167-28-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 2022-04-29 16:40:52 +02:00			`/*`
			`* CXL host parameter parsing routine stubs`
			`*`
			`* Copyright (c) 2022 Huawei`
			`*/`
			`#include "qemu/osdep.h"`
			`#include "qapi/error.h"`
			`#include "hw/cxl/cxl.h"`
hw/cxl: Make the CXL fixed memory window setup a machine parameter. Paolo Bonzini requested this change to simplify the ongoing effort to allow machine setup entirely via RPC. Includes shortening the command line form cxl-fixed-memory-window to cxl-fmw as the command lines are extremely long even with this change. The json change is needed to ensure that there is a CXLFixedMemoryWindowOptionsList even though the actual element in the json is never used. Similar to existing SgxEpcProperties. Update qemu-options.hx to reflect that this is now a -machine parameter. The bulk of -M / -machine parameters are documented under machine, so use that in preference to M. Update cxl-test and bios-tables-test to reflect new parameters. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben@bwidawsk.net> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Message-Id: <20220608145440.26106-2-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 2022-06-08 16:54:33 +02:00			`#include "hw/cxl/cxl_host.h"`
hw/cxl/host: Add support for CXL Fixed Memory Windows. The concept of these is introduced in [1] in terms of the description the CEDT ACPI table. The principal is more general. Unlike once traffic hits the CXL root bridges, the host system memory address routing is implementation defined and effectively static once observable by standard / generic system software. Each CXL Fixed Memory Windows (CFMW) is a region of PA space which has fixed system dependent routing configured so that accesses can be routed to the CXL devices below a set of target root bridges. The accesses may be interleaved across multiple root bridges. For QEMU we could have fully specified these regions in terms of a base PA + size, but as the absolute address does not matter it is simpler to let individual platforms place the memory regions. ExampleS: -cxl-fixed-memory-window targets.0=cxl.0,size=128G -cxl-fixed-memory-window targets.0=cxl.1,size=128G -cxl-fixed-memory-window targets.0=cxl0,targets.1=cxl.1,size=256G,interleave-granularity=2k Specifies * 2x 128G regions not interleaved across root bridges, one for each of the root bridges with ids cxl.0 and cxl.1 * 256G region interleaved across root bridges with ids cxl.0 and cxl.1 with a 2k interleave granularity. When system software enumerates the devices below a given root bridge it can then decide which CFMW to use. If non interleave is desired (or possible) it can use the appropriate CFMW for the root bridge in question. If there are suitable devices to interleave across the two root bridges then it may use the 3rd CFMS. A number of other designs were considered but the following constraints made it hard to adapt existing QEMU approaches to this particular problem. 1) The size must be known before a specific architecture / board brings up it's PA memory map. We need to set up an appropriate region. 2) Using links to the host bridges provides a clean command line interface but these links cannot be established until command line devices have been added. Hence the two step process used here of first establishing the size, interleave-ways and granularity + caching the ids of the host bridges and then, once available finding the actual host bridges so they can be used later to support interleave decoding. [1] CXL 2.0 ECN: CEDT CFMWS & QTG DSM (computeexpresslink.org / specifications) Signed-off-by: Jonathan Cameron <jonathan.cameron@huawei.com> Acked-by: Markus Armbruster <armbru@redhat.com> # QAPI Schema Message-Id: <20220429144110.25167-28-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 2022-04-29 16:40:52 +02:00
hw/cxl: Push linking of CXL targets into i386/pc rather than in machine.c Whilst here take the oportunity to shorten the function name. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben@bwidawsk.net> Message-Id: <20220608145440.26106-4-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 2022-06-08 16:54:35 +02:00			`void cxl_fmws_link_targets(CXLState stat, Error *errp) {};`
hw/cxl: Make the CXL fixed memory window setup a machine parameter. Paolo Bonzini requested this change to simplify the ongoing effort to allow machine setup entirely via RPC. Includes shortening the command line form cxl-fixed-memory-window to cxl-fmw as the command lines are extremely long even with this change. The json change is needed to ensure that there is a CXLFixedMemoryWindowOptionsList even though the actual element in the json is never used. Similar to existing SgxEpcProperties. Update qemu-options.hx to reflect that this is now a -machine parameter. The bulk of -M / -machine parameters are documented under machine, so use that in preference to M. Update cxl-test and bios-tables-test to reflect new parameters. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben@bwidawsk.net> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Message-Id: <20220608145440.26106-2-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 2022-06-08 16:54:33 +02:00			`void cxl_machine_init(Object obj, CXLState state) {};`
pci/pci_expander_bridge: For CXL HB delay the HB register memory region setup. As the CXLState will no long be accessible via MachineState at time of PXB_CXL realization, come back later from the machine specific code to fill in the missing memory region setup. Only at this stage is it possible to check if cxl=on, so that check is moved to this later point. Note that for multiple host bridges, the allocation order of the register spaces is changed. This will be reflected in ACPI CEDT. Stubs are added to handle case of CONFIG_PXB=n for machines that call these functions. The bus walking logic is common to all machines so add a utility function + stub to cxl-host*. Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Ben Widawsky <ben@bwidawsk.net> Message-Id: <20220608145440.26106-6-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 2022-06-08 16:54:37 +02:00			`void cxl_hook_up_pxb_registers(PCIBus bus, CXLState state, Error **errp) {};`
cxl/cxl-host: Add memops for CFMWS region. These memops perform interleave decoding, walking down the CXL topology from CFMWS described host interleave decoder via CXL host bridge HDM decoders, through the CXL root ports and finally call CXL type 3 specific read and write functions. Note that, whilst functional the current implementation does not support: * switches * multiple HDM decoders at a given level. * unaligned accesses across the interleave boundaries Signed-off-by: Jonathan Cameron <jonathan.cameron@huawei.com> Message-Id: <20220429144110.25167-34-Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 2022-04-29 16:40:58 +02:00
			`const MemoryRegionOps cfmws_ops;`