hw/cxl: Add Physical Port Control FMAPI Command (Opcode 5102h)
Added assert-deassert PERST implementation for physical ports (both USP and DSP's). Assert PERST involves bg operation for holding 100ms. Reset PPB implementation for physical ports. Signed-off-by: Arpit Kumar <arpit1.kumar@samsung.com> Co-developed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-Id: <20260204173223.44122-4-Jonathan.Cameron@huawei.com>
Arpit Kumar committed
Feb 4, 2026 at 17:32 UTC
6e1410fdcf7040b2c32a7845b423ab604384aded
6 files changed
+174
hw/cxl/cxl-mailbox-utils.c
+130
@@ -17,6 +17,7 @@
17
#include "hw/cxl/cxl_mailbox.h"
18
#include "hw/cxl/cxl_port.h"
19
#include "hw/pci/pci.h"
20
+#include "hw/pci-bridge/cxl_downstream_port.h"
21
#include "hw/pci-bridge/cxl_upstream_port.h"
22
#include "qemu/cutils.h"
23
#include "qemu/host-utils.h"
@@ -119,6 +120,7 @@ enum {
120
PHYSICAL_SWITCH = 0x51,
121
#define IDENTIFY_SWITCH_DEVICE 0x0
122
#define GET_PHYSICAL_PORT_STATE 0x1
123
+ #define PHYSICAL_PORT_CONTROL 0x2
124
TUNNEL = 0x53,
125
#define MANAGEMENT_COMMAND 0x0
126
FMAPI_DCD_MGMT = 0x56,
@@ -616,6 +618,7 @@ static CXLRetCode cmd_get_physical_port_state(const struct cxl_cmd *cmd,
618
struct cxl_fmapi_port_state_info_block *port;
619
/* First try to match on downstream port */
620
PCIDevice *port_dev;
621
+ CXLPhyPortPerst *perst;
622
uint16_t lnkcap, lnkcap2, lnksta;
623
624
port = &out->ports[i];
@@ -663,6 +666,7 @@ static CXLRetCode cmd_get_physical_port_state(const struct cxl_cmd *cmd,
666
port->supported_cxl_mode_bitmask = CXL_PORT_SUPPORTS_68B_VH |
667
CXL_PORT_SUPPORTS_256B;
668
port->supported_ld_count = 3;
669
+ perst = cxl_dsp_get_perst(CXL_DSP(port_dev));
670
} else if (usp->port == in->ports[i]) { /* USP */
671
port_dev = PCI_DEVICE(usp);
672
port->config_state = CXL_PORT_CONFIG_STATE_USP;
@@ -670,6 +674,7 @@ static CXLRetCode cmd_get_physical_port_state(const struct cxl_cmd *cmd,
674
port->connected_device_mode = 0; /* Reserved for USP */
675
port->supported_cxl_mode_bitmask = CXL_PORT_SUPPORTS_68B_VH |
676
(CXL_USP(usp)->flitmode ? CXL_PORT_SUPPORTS_256B : 0);
677
+ perst = &CXL_USP(usp)->perst;
678
} else {
679
return CXL_MBOX_INVALID_INPUT;
680
}
@@ -698,6 +703,7 @@ static CXLRetCode cmd_get_physical_port_state(const struct cxl_cmd *cmd,
703
/* TODO: Track down if we can get the rest of the info */
704
port->ltssm_state = 0x7;
705
port->first_lane_num = 0;
706
+ port->link_state = perst ? CXL_PORT_LINK_STATE_FLAG_PERST_ASSERTED : 0;
707
}
708
709
pl_size = sizeof(*out) + sizeof(*out->ports) * in->num_ports;
@@ -706,6 +712,115 @@ static CXLRetCode cmd_get_physical_port_state(const struct cxl_cmd *cmd,
712
return CXL_MBOX_SUCCESS;
713
}
714
715
+static void *bg_assertcb(void *opaque)
716
+{
717
+ CXLPhyPortPerst *perst = opaque;
718
+
719
+ /* holding reset phase for 100ms */
720
+ while (perst->asrt_time--) {
721
+ usleep(1000);
722
+ }
723
+ perst->issued_assert_perst = true;
724
+ return NULL;
725
+}
726
+
727
+static CXLRetCode cxl_deassert_perst(Object *obj, CXLPhyPortPerst *perst)
728
+{
729
+ if (!perst->issued_assert_perst) {
730
+ return CXL_MBOX_INTERNAL_ERROR;
731
+ }
732
+
733
+ QEMU_LOCK_GUARD(&perst->lock);
734
+ resettable_release_reset(obj, RESET_TYPE_COLD);
735
+ perst->issued_assert_perst = false;
736
+ perst->asrt_time = ASSERT_WAIT_TIME_MS;
737
+
738
+ return CXL_MBOX_SUCCESS;
739
+}
740
+
741
+static CXLRetCode cxl_assert_perst(Object *obj, CXLPhyPortPerst *perst)
742
+{
743
+ if (cxl_perst_asserted(perst)) {
744
+ return CXL_MBOX_INTERNAL_ERROR;
745
+ }
746
+
747
+ QEMU_LOCK_GUARD(&perst->lock);
748
+ resettable_assert_reset(obj, RESET_TYPE_COLD);
749
+ qemu_thread_create(&perst->asrt_thread, "assert_thread", bg_assertcb,
750
+ perst, QEMU_THREAD_DETACHED);
751
+
752
+ return CXL_MBOX_SUCCESS;
753
+}
754
+
755
+static CXLDownstreamPort *cxl_find_dsp_on_bus(PCIBus *bus, uint8_t pn)
756
+{
757
+
758
+ PCIDevice *port_dev = pcie_find_port_by_pn(bus, pn);
759
+
760
+ if (object_dynamic_cast(OBJECT(port_dev), TYPE_CXL_DSP)) {
761
+ return CXL_DSP(port_dev);
762
+ }
763
+
764
+ return NULL;
765
+}
766
+
767
+/* CXL r3.2 Section 7.6.7.1.3: Get Physical Port Control (Opcode 5102h) */
768
+static CXLRetCode cmd_physical_port_control(const struct cxl_cmd *cmd,
769
+ uint8_t *payload_in,
770
+ size_t len_in,
771
+ uint8_t *payload_out,
772
+ size_t *len_out,
773
+ CXLCCI *cci)
774
+{
775
+ CXLUpstreamPort *pp = CXL_USP(cci->d);
776
+ CXLPhyPortPerst *perst;
777
+ PCIDevice *dev;
778
+
779
+ struct cxl_fmapi_get_physical_port_control_req_pl {
780
+ uint8_t ppb_id;
781
+ uint8_t ports_op;
782
+ } QEMU_PACKED *in = (void *)payload_in;
783
+
784
+ if (len_in < sizeof(*in)) {
785
+ return CXL_MBOX_INVALID_PAYLOAD_LENGTH;
786
+ }
787
+
788
+ if (PCIE_PORT(pp)->port == in->ppb_id) {
789
+ dev = PCI_DEVICE(pp);
790
+ perst = &pp->perst;
791
+ } else {
792
+ CXLDownstreamPort *dsp =
793
+ cxl_find_dsp_on_bus(&PCI_BRIDGE(pp)->sec_bus, in->ppb_id);
794
+
795
+ if (!dsp) {
796
+ return CXL_MBOX_INVALID_INPUT;
797
+ }
798
+ dev = PCI_DEVICE(dsp);
799
+ perst = cxl_dsp_get_perst(dsp);
800
+ }
801
+
802
+ switch (in->ports_op) {
803
+ case 0:
804
+ return cxl_assert_perst(OBJECT(&dev->qdev), perst);
805
+ case 1:
806
+ return cxl_deassert_perst(OBJECT(&dev->qdev), perst);
807
+ case 2: {
808
+ if (!perst) {
809
+ return CXL_MBOX_INVALID_INPUT;
810
+ }
811
+
812
+ if (perst->issued_assert_perst ||
813
+ perst->asrt_time < ASSERT_WAIT_TIME_MS) {
814
+ return CXL_MBOX_INTERNAL_ERROR;
815
+ }
816
+ device_cold_reset(&dev->qdev);
817
+ return CXL_MBOX_SUCCESS;
818
+ }
819
+ default:
820
+ return CXL_MBOX_INVALID_INPUT;
821
+ }
822
+}
823
+
824
/* CXL r3.1 Section 8.2.9.1.2: Background Operation Status (Opcode 0002h) */
825
static CXLRetCode cmd_infostat_bg_op_sts(const struct cxl_cmd *cmd,
826
uint8_t *payload_in,
@@ -4412,6 +4527,8 @@ static const struct cxl_cmd cxl_cmd_set_sw[256][256] = {
4527
cmd_identify_switch_device, 0, 0 },
4528
[PHYSICAL_SWITCH][GET_PHYSICAL_PORT_STATE] = { "SWITCH_PHYSICAL_PORT_STATS",
4529
cmd_get_physical_port_state, ~0, 0 },
4530
+ [PHYSICAL_SWITCH][PHYSICAL_PORT_CONTROL] = { "SWITCH_PHYSICAL_PORT_CONTROL",
4531
+ cmd_physical_port_control, 2, 0 },
4532
[TUNNEL][MANAGEMENT_COMMAND] = { "TUNNEL_MANAGEMENT_COMMAND",
4533
cmd_tunnel_management_cmd, ~0, 0 },
4534
};
@@ -4618,6 +4735,19 @@ static void cxl_rebuild_cel(CXLCCI *cci)
4735
}
4736
}
4737
4738
+void cxl_init_physical_port_control(CXLPhyPortPerst *perst)
4739
+{
4740
+ qemu_mutex_init(&perst->lock);
4741
+ perst->issued_assert_perst = false;
4742
+ /*
4743
+ * Assert PERST involves physical port to be in
4744
+ * hold reset phase for minimum 100ms. No other
4745
+ * physical port control requests are entertained
4746
+ * until Deassert PERST command.
4747
+ */
4748
+ perst->asrt_time = ASSERT_WAIT_TIME_MS;
4749
+}
4750
+
4751
void cxl_init_cci(CXLCCI *cci, size_t payload_max)
4752
{
4753
cci->payload_max = payload_max;
hw/pci-bridge/cxl_downstream.c
+9
@@ -13,9 +13,11 @@
13
#include "hw/pci/msi.h"
14
#include "hw/pci/pcie.h"
15
#include "hw/pci/pcie_port.h"
16
+#include "hw/pci-bridge/cxl_downstream_port.h"
17
#include "hw/core/qdev-properties.h"
18
#include "hw/core/qdev-properties-system.h"
19
#include "hw/cxl/cxl.h"
20
+#include "hw/cxl/cxl_port.h"
21
#include "qapi/error.h"
22
23
typedef struct CXLDownstreamPort {
@@ -24,6 +26,7 @@ typedef struct CXLDownstreamPort {
26
27
/*< public >*/
28
CXLComponentState cxl_cstate;
29
+ CXLPhyPortPerst perst;
30
} CXLDownstreamPort;
31
32
#define CXL_DOWNSTREAM_PORT_MSI_OFFSET 0x70
@@ -81,6 +84,11 @@ static void cxl_dsp_config_write(PCIDevice *d, uint32_t address,
84
cxl_dsp_dvsec_write_config(d, address, val, len);
85
}
86
87
+CXLPhyPortPerst *cxl_dsp_get_perst(CXLDownstreamPort *dsp)
88
+{
89
+ return &dsp->perst;
90
+}
91
+
92
static void cxl_dsp_reset(DeviceState *qdev)
93
{
94
PCIDevice *d = PCI_DEVICE(qdev);
@@ -92,6 +100,7 @@ static void cxl_dsp_reset(DeviceState *qdev)
100
pci_bridge_reset(qdev);
101
102
latch_registers(dsp);
103
+ cxl_init_physical_port_control(&dsp->perst);
104
}
105
106
static void build_dvsecs(PCIDevice *d, CXLComponentState *cxl)
hw/pci-bridge/cxl_upstream.c
+1
@@ -103,6 +103,7 @@ static void cxl_usp_reset(DeviceState *qdev)
103
pcie_cap_deverr_reset(d);
104
pcie_cap_fill_link_ep_usp(d, usp->width, usp->speed, usp->flitmode);
105
latch_registers(usp);
106
+ cxl_init_physical_port_control(&usp->perst);
107
}
108
109
static void build_dvsecs(CXLUpstreamPort *usp)
include/hw/cxl/cxl_port.h
+20
@@ -3,6 +3,8 @@
3
#ifndef CXL_PORT_H
4
#define CXL_PORT_H
5
6
+#include "qemu/thread.h"
7
+
8
/* CXL r3.2 Table 7-19: Get Physical Port State Port Information Block Format */
9
#define CXL_PORT_CONFIG_STATE_DISABLED 0x0
10
#define CXL_PORT_CONFIG_STATE_BIND_IN_PROGRESS 0x1
@@ -50,4 +52,22 @@
52
#define CXL_PORT_LINK_STATE_FLAG_PRSNT BIT(2)
53
#define CXL_PORT_LINK_STATE_FLAG_POWER_OFF BIT(3)
54
55
+#define CXL_MAX_PHY_PORTS 256
56
+#define ASSERT_WAIT_TIME_MS 100 /* Assert - Deassert PERST */
57
+
58
+/* Assert - Deassert PERST */
59
+typedef struct CXLPhyPortPerst {
60
+ bool issued_assert_perst;
61
+ QemuMutex lock; /* protecting assert-deassert reset request */
62
+ uint64_t asrt_time;
63
+ QemuThread asrt_thread; /* thread for 100ms delay */
64
+} CXLPhyPortPerst;
65
+
66
+void cxl_init_physical_port_control(CXLPhyPortPerst *perst);
67
+
68
+static inline bool cxl_perst_asserted(CXLPhyPortPerst *perst)
69
+{
70
+ return perst->issued_assert_perst || perst->asrt_time < ASSERT_WAIT_TIME_MS;
71
+}
72
+
73
#endif /* CXL_PORT_H */
include/hw/pci-bridge/cxl_downstream_port.h
new
+12
@@ -0,0 +1,12 @@
1
+/*
2
+ * SPDX-License-Identifier: GPL-2.0-or-later
3
+ */
4
+
5
+#ifndef CXL_DOWNSTREAM_PORT_H
6
+#define CXL_DOWNSTREAM_PORT_H
7
+#include "include/hw/cxl/cxl_port.h"
8
+
9
+typedef struct CXLDownstreamPort CXLDownstreamPort;
10
+CXLPhyPortPerst *cxl_dsp_get_perst(CXLDownstreamPort *dsp);
11
+
12
+#endif
include/hw/pci-bridge/cxl_upstream_port.h
+2
@@ -4,6 +4,7 @@
4
#include "hw/pci/pcie.h"
5
#include "hw/pci/pcie_port.h"
6
#include "hw/cxl/cxl.h"
7
+#include "hw/cxl/cxl_port.h"
8
9
typedef struct CXLUpstreamPort {
10
/*< private >*/
@@ -12,6 +13,7 @@ typedef struct CXLUpstreamPort {
13
/*< public >*/
14
CXLComponentState cxl_cstate;
15
CXLCCI swcci;
16
+ CXLPhyPortPerst perst;
17
18
PCIExpLinkSpeed speed;
19
PCIExpLinkWidth width;