Signed-off-by: Clément Mathieu--Drif <clement.mathieu--drif@eviden.com>
---
 hw/pci/pcie.c                             | 24 +++++++++++++++++++++++
 include/hw/pci/pcie.h                     |  6 +++++-
 include/hw/pci/pcie_regs.h                |  3 +++
 include/standard-headers/linux/pci_regs.h |  1 +
 4 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 4b2f0805c6..d6a052b616 100644
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -1177,3 +1177,27 @@ void pcie_acs_reset(PCIDevice *dev)
         pci_set_word(dev->config + dev->exp.acs_cap + PCI_ACS_CTRL, 0);
     }
 }
+
+/* PASID */
+void pcie_pasid_init(PCIDevice *dev, uint16_t offset, uint8_t pasid_width,
+                     bool exec_perm, bool priv_mod)
+{
+    assert(pasid_width <= PCI_EXT_CAP_PASID_MAX_WIDTH);
+    static const uint16_t control_reg_rw_mask = 0x07;
+    uint16_t capability_reg = pasid_width;
+
+    pcie_add_capability(dev, PCI_EXT_CAP_ID_PASID, PCI_PASID_VER, offset,
+                        PCI_EXT_CAP_PASID_SIZEOF);
+
+    capability_reg <<= PCI_PASID_CAP_WIDTH_SHIFT;
+    capability_reg |= exec_perm ? PCI_PASID_CAP_EXEC : 0;
+    capability_reg |= priv_mod  ? PCI_PASID_CAP_PRIV : 0;
+    pci_set_word(dev->config + offset + PCI_PASID_CAP, capability_reg);
+
+    /* Everything is disabled by default */
+    pci_set_word(dev->config + offset + PCI_PASID_CTRL, 0);
+
+    pci_set_word(dev->wmask + offset + PCI_PASID_CTRL, control_reg_rw_mask);
+
+    dev->exp.pasid_cap = offset;
+}
diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
index 5eddb90976..b870958c99 100644
--- a/include/hw/pci/pcie.h
+++ b/include/hw/pci/pcie.h
@@ -72,8 +72,9 @@ struct PCIExpressDevice {
     uint16_t aer_cap;
     PCIEAERLog aer_log;
 
-    /* Offset of ATS capability in config space */
+    /* Offset of ATS and PASID capabilities in config space */
     uint16_t ats_cap;
+    uint16_t pasid_cap;
 
     /* ACS */
     uint16_t acs_cap;
@@ -150,4 +151,7 @@ void pcie_cap_slot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
                              Error **errp);
 void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
                                      DeviceState *dev, Error **errp);
+
+void pcie_pasid_init(PCIDevice *dev, uint16_t offset, uint8_t pasid_width,
+                     bool exec_perm, bool priv_mod);
 #endif /* QEMU_PCIE_H */
diff --git a/include/hw/pci/pcie_regs.h b/include/hw/pci/pcie_regs.h
index 9d3b6868dc..0a86598f80 100644
--- a/include/hw/pci/pcie_regs.h
+++ b/include/hw/pci/pcie_regs.h
@@ -86,6 +86,9 @@ typedef enum PCIExpLinkWidth {
 #define PCI_ARI_VER                     1
 #define PCI_ARI_SIZEOF                  8
 
+/* PASID */
+#define PCI_PASID_VER                   1
+#define PCI_EXT_CAP_PASID_MAX_WIDTH     20
 /* AER */
 #define PCI_ERR_VER                     2
 #define PCI_ERR_SIZEOF                  0x48
diff --git a/include/standard-headers/linux/pci_regs.h b/include/standard-headers/linux/pci_regs.h
index a39193213f..406dce8e82 100644
--- a/include/standard-headers/linux/pci_regs.h
+++ b/include/standard-headers/linux/pci_regs.h
@@ -935,6 +935,7 @@
 #define  PCI_PASID_CAP_EXEC	0x0002	/* Exec permissions Supported */
 #define  PCI_PASID_CAP_PRIV	0x0004	/* Privilege Mode Supported */
 #define  PCI_PASID_CAP_WIDTH	0x1f00
+#define  PCI_PASID_CAP_WIDTH_SHIFT  8
 #define PCI_PASID_CTRL		0x06    /* PASID control register */
 #define  PCI_PASID_CTRL_ENABLE	0x0001	/* Enable bit */
 #define  PCI_PASID_CTRL_EXEC	0x0002	/* Exec permissions Enable */
-- 
2.44.0