pcie: Helper functions to check if PASID is enabled

pasid_enabled checks whether the capability is
present or not. If so, we read the configuration space to get
the status of the feature (enabled or not).

Signed-off-by: Clement Mathieu--Drif <clement.mathieu--drif@eviden.com>
Message-Id: <20250520071823.764266-3-clement.mathieu--drif@eviden.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
index 4f935ff420bc432216279a41d1aadcde2afd6b42..db9756d8619a6bedba3c57cf7f4b8968521f97a1 100644 (file)
--- a/hw/pci/pcie.c
+++ b/hw/pci/pcie.c
@@ -1239,3 +1239,12 @@ void pcie_pasid_init(PCIDevice *dev, uint16_t offset, uint8_t pasid_width,
 
     dev->exp.pasid_cap = offset;
 }
+
+bool pcie_pasid_enabled(const PCIDevice *dev)
+{
+    if (!pci_is_express(dev) || !dev->exp.pasid_cap) {
+        return false;
+    }
+    return (pci_get_word(dev->config + dev->exp.pasid_cap + PCI_PASID_CTRL) &
+                PCI_PASID_CTRL_ENABLE) != 0;
+}

diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
index fe82e0a9152c68f3cbb01ac83b44930660a862e2..dff98ff2c6755a5354a5c7e66a5d0993a675cf4b 100644 (file)
--- a/include/hw/pci/pcie.h
+++ b/include/hw/pci/pcie.h
@@ -154,4 +154,6 @@ void pcie_cap_slot_unplug_request_cb(HotplugHandler *hotplug_dev,
 
 void pcie_pasid_init(PCIDevice *dev, uint16_t offset, uint8_t pasid_width,
                      bool exec_perm, bool priv_mod);
+
+bool pcie_pasid_enabled(const PCIDevice *dev);
 #endif /* QEMU_PCIE_H */