To establish performance characteristics of a CXL device when used via a
particular CXL topology (root ports, switches, end points) it is necessary
to set the appropriate link speed and width in the PCI Express capability
structure. Provide x-speed and x-link properties for this.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
include/hw/cxl/cxl_device.h | 4 ++++
hw/mem/cxl_type3.c | 6 ++++++
2 files changed, 10 insertions(+)
diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
index fdd0f4e62b..e14e56ae4b 100644
--- a/include/hw/cxl/cxl_device.h
+++ b/include/hw/cxl/cxl_device.h
@@ -549,6 +549,10 @@ struct CXLType3Dev {
CXLCCI vdm_fm_owned_ld_mctp_cci;
CXLCCI ld0_cci;
+ /* PCIe link characteristics */
+ PCIExpLinkSpeed speed;
+ PCIExpLinkWidth width;
+
/* DOE */
DOECap doe_cdat;
diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index 235ac40aeb..44d491d8f6 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -17,6 +17,7 @@
#include "hw/mem/pc-dimm.h"
#include "hw/pci/pci.h"
#include "hw/qdev-properties.h"
+#include "hw/qdev-properties-system.h"
#include "qapi/error.h"
#include "qemu/log.h"
#include "qemu/module.h"
@@ -1200,6 +1201,7 @@ static void ct3d_reset(DeviceState *dev)
uint32_t *reg_state = ct3d->cxl_cstate.crb.cache_mem_registers;
uint32_t *write_msk = ct3d->cxl_cstate.crb.cache_mem_regs_write_mask;
+ pcie_cap_fill_link_ep_usp(PCI_DEVICE(dev), ct3d->width, ct3d->speed);
cxl_component_register_init_common(reg_state, write_msk, CXL2_TYPE3_DEVICE);
cxl_device_register_init_t3(ct3d);
@@ -1229,6 +1231,10 @@ static Property ct3_props[] = {
DEFINE_PROP_UINT8("num-dc-regions", CXLType3Dev, dc.num_regions, 0),
DEFINE_PROP_LINK("volatile-dc-memdev", CXLType3Dev, dc.host_dc,
TYPE_MEMORY_BACKEND, HostMemoryBackend *),
+ DEFINE_PROP_PCIE_LINK_SPEED("x-speed", CXLType3Dev,
+ speed, PCIE_LINK_SPEED_32),
+ DEFINE_PROP_PCIE_LINK_WIDTH("x-width", CXLType3Dev,
+ width, PCIE_LINK_WIDTH_16),
DEFINE_PROP_END_OF_LIST(),
};
--
2.43.0