dm: PTM: Check if hw supports ptm

This patch probes whether hw supports ptm.  It is used to check whether ptm
	can be enabled on the passthru pci device.  It checks whether passthru
	device support PTM requestor capability, then check whether its upstream
	root port support PTM root role.  Errors are reported to user if sanity
	check fails.

Tracked-On: #5915
Signed-off-by: Rong Liu <rong.l.liu@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>

devicemodel/Makefile

@@ -131,6 +131,7 @@ SRCS += hw/pci/platform_gsi_info.c
 SRCS += hw/pci/gsi_sharing.c
 SRCS += hw/pci/passthrough.c
 SRCS += hw/pci/pci_util.c
+SRCS += hw/pci/ptm.c
 SRCS += hw/pci/virtio/virtio_audio.c
 SRCS += hw/pci/virtio/virtio_net.c
 SRCS += hw/pci/virtio/virtio_rnd.c

devicemodel/hw/pci/passthrough.c

@@ -46,7 +46,7 @@
 #include "pci_core.h"
 #include "acpi.h"
 #include "dm.h"
-
+#include "passthru.h"
 
 /* Some audio drivers get topology data from ACPI NHLT table.
  * For such drivers, we need to copy the host NHLT table to make it
@@ -70,32 +70,6 @@ uint32_t gpu_opregion_gpa = 0;
 static int pciaccess_ref_cnt;
 static pthread_mutex_t ref_cnt_mtx = PTHREAD_MUTEX_INITIALIZER;
 
-
-struct passthru_dev {
-	struct pci_vdev *dev;
-	struct pcibar bar[PCI_BARMAX + 1];
-	struct {
-		int		capoff;
-	} msi;
-	struct {
-		int		capoff;
-	} msix;
-	struct {
-		int 		capoff;
-	} pmcap;
-	bool pcie_cap;
-	struct pcisel sel;
-	int phys_pin;
-	uint16_t phys_bdf;
-	struct pci_device *phys_dev;
-	/* Options for passthrough device:
-	 *   need_reset - reset dev before passthrough
-	 */
-	bool need_reset;
-	bool d3hot_reset;
-	bool (*has_virt_pcicfg_regs)(int offset);
-};
-
 static uint32_t
 read_config(struct pci_device *phys_dev, long reg, int width)
 {

devicemodel/hw/pci/ptm.c

@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2021 Intel Corporation.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/queue.h>
+
+#include "pcireg.h"
+#include "pciaccess.h"
+#include "pci_core.h"
+#include "ptm.h"
+#include "passthru.h"
+#include "pci_util.h"
+#include "vmmapi.h"
+
+/* PTM capability register ID*/
+#define PCIZ_PTM    0x1fU
+
+/* PTM register Definitions */
+/* PTM capability register */
+#define PCIR_PTM_CAP				0x04U
+	#define PCIM_PTM_CAP_REQ		0x01U	/* Requestor capable */
+	#define PCIM_PTM_CAP_ROOT		0x4U	/* Root capable */
+	#define PCIM_PTM_GRANULARITY	0xFF00	/* Clock granularity */
+/* PTM control register */
+#define PCIR_PTM_CTRL				0x08U
+	#define PCIM_PTM_CTRL_ENABLE	0x1U	/* PTM enable */
+	#define PCIM_PTM_CTRL_ROOT_SELECT	0x2U	/* Root select */
+
+/* get ptm capability register value */
+static int
+get_ptm_cap(struct pci_device *pdev, int *offset)
+{
+	int pos;
+	uint32_t cap;
+
+	pos = pci_find_ext_cap(pdev, PCIZ_PTM);
+
+	if (!pos) {
+		*offset = 0;
+		return 0;
+	}
+
+	*offset = pos;
+	pci_device_cfg_read_u32(pdev, &cap, pos + PCIR_PTM_CAP);
+
+	pr_notice("<PTM>-%s: device [%x:%x.%x]: ptm-cap=0x%x, offset=0x%x.\n",
+				__func__, pdev->bus, pdev->dev, pdev->func, cap, *offset);
+
+	return cap;
+}
+
+/* Probe whether device and its root port support PTM */
+int ptm_probe(struct vmctx *ctx, struct passthru_dev *ptdev)
+{
+	int pos, pcie_type, cap, rootport_ptm_offset, device_ptm_offset;
+	struct pci_device *phys_dev = ptdev->phys_dev;
+	struct pci_device *root_port;
+
+	if (!ptdev->pcie_cap) {
+		pr_err("%s Error: %x:%x.%x is not a pci-e device.\n", __func__,
+				phys_dev->bus, phys_dev->dev, phys_dev->func);
+		return -EINVAL;
+	}
+
+	pos = pci_find_ext_cap(phys_dev, PCIZ_PTM);
+	if (!pos) {
+		pr_err("%s Error: %x:%x.%x doesn't support ptm.\n", __func__,
+				phys_dev->bus, phys_dev->dev, phys_dev->func);
+		return -EINVAL;
+	}
+
+	pcie_type = pci_get_pcie_type(phys_dev);
+
+	/* Assume that PTM requestor can be enabled on pci ep or rcie.
+	 * If PTM is enabled on an ep, PTM hierarchy requires it has an upstream
+	 * PTM root.  Based on available HW platforms, currently PTM root
+	 * capability is implemented in pci root port.
+	 */
+	if (pcie_type == PCIEM_TYPE_ENDPOINT) {
+		cap = get_ptm_cap(phys_dev, &device_ptm_offset);
+		if (!(cap & PCIM_PTM_CAP_REQ)) {
+			pr_err("%s Error: %x:%x.%x must be PTM requestor.\n", __func__,
+					phys_dev->bus, phys_dev->dev, phys_dev->func);
+			return -EINVAL;
+		}
+
+		root_port = pci_find_root_port(phys_dev);
+		if (root_port == NULL) {
+			pr_err("%s Error: Cannot find root port of %x:%x.%x.\n", __func__,
+					phys_dev->bus, phys_dev->dev, phys_dev->func);
+			return -ENODEV;
+		}
+
+		cap = get_ptm_cap(root_port, &rootport_ptm_offset);
+		if (!(cap & PCIM_PTM_CAP_ROOT)) {
+			pr_err("%s Error: root port %x:%x.%x of %x:%x.%x is not PTM root.\n",
+				__func__, root_port->bus, root_port->dev,
+				root_port->func, phys_dev->bus, phys_dev->dev, phys_dev->func);
+			return -EINVAL;
+		}
+	} else if (pcie_type == PCIEM_TYPE_ROOT_INT_EP) {
+		// No need to emulate root port if ptm requestor is RCIE
+		pr_notice("%s: ptm requestor is root complex integrated device.\n",
+					__func__);
+	} else {
+		pr_err("%s Error: PTM can only be enabled on pci root complex integrated device or endpoint device.\n",
+					__func__);
+		return -EINVAL;
+	}
+
+	return 0;
+}

devicemodel/include/passthru.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2021 Intel Corporation.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef __PASSTHRU_H__
+#define __PASSTHRU_H__
+
+#include <types.h>
+
+#include "pciaccess.h"
+#include "pci_core.h"
+#include "pciio.h"
+
+struct passthru_dev {
+	struct pci_vdev *dev;
+	struct pcibar bar[PCI_BARMAX + 1];
+	struct {
+		int		capoff;
+	} msi;
+	struct {
+		int		capoff;
+	} msix;
+	struct {
+		int 		capoff;
+	} pmcap;
+	bool pcie_cap;
+	struct pcisel sel;
+	int phys_pin;
+	uint16_t phys_bdf;
+	struct pci_device *phys_dev;
+	/* Options for passthrough device:
+	 *   need_reset - reset dev before passthrough
+	 */
+	bool need_reset;
+	bool d3hot_reset;
+	bool (*has_virt_pcicfg_regs)(int offset);
+};
+
+#endif

devicemodel/include/ptm.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) 2021 Intel Corporation.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef __PTM_H__
+#define __PTM_H__
+
+#include "passthru.h"
+
+int ptm_probe(struct vmctx *ctx, struct passthru_dev *pdev);
+
+#endif