x86/pci/xen: populate MSI sysfs entries

Commit bf5e758f02fc ("genirq/msi: Simplify sysfs handling") reworked the
creation of sysfs entries for MSI IRQs. The creation used to be in
msi_domain_alloc_irqs_descs_locked after calling ops->domain_alloc_irqs.
Then it moved into __msi_domain_alloc_irqs which is an implementation of
domain_alloc_irqs. However, Xen comes with the only other implementation
of domain_alloc_irqs and hence doesn't run the sysfs population code
anymore.

Commit 6c796996ee70 ("x86/pci/xen: Fixup fallout from the PCI/MSI
overhaul") set the flag MSI_FLAG_DEV_SYSFS for the xen msi_domain_info
but that doesn't actually have an effect because Xen uses it's own
domain_alloc_irqs implementation.

Fix this by making use of the fallback functions for sysfs population.

Fixes: bf5e758f02fc ("genirq/msi: Simplify sysfs handling")
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230503131656.15928-1-mheyne@amazon.de
Signed-off-by: Juergen Gross <jgross@suse.com>

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 8babce71915fe514aa24cfdb25f36c98ddc90369..014c508e914d9816bb062621554c65231468870a 100644 (file)
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -198,7 +198,7 @@ static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
                i++;
        }
        kfree(v);
-       return 0;
+       return msi_device_populate_sysfs(&dev->dev);
 
 error:
        if (ret == -ENOSYS)
@@ -254,7 +254,7 @@ static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
                dev_dbg(&dev->dev,
                        "xen: msi --> pirq=%d --> irq=%d\n", pirq, irq);
        }
-       return 0;
+       return msi_device_populate_sysfs(&dev->dev);
 
 error:
        dev_err(&dev->dev, "Failed to create MSI%s! ret=%d!\n",
@@ -346,7 +346,7 @@ static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
                if (ret < 0)
                        goto out;
        }
-       ret = 0;
+       ret = msi_device_populate_sysfs(&dev->dev);
 out:
        return ret;
 }
@@ -394,6 +394,8 @@ static void xen_teardown_msi_irqs(struct pci_dev *dev)
                        xen_destroy_irq(msidesc->irq + i);
                msidesc->irq = 0;
        }
+
+       msi_device_destroy_sysfs(&dev->dev);
 }
 
 static void xen_pv_teardown_msi_irqs(struct pci_dev *dev)

diff --git a/include/linux/msi.h b/include/linux/msi.h
index cdb14a1ef26810c26a54b94efb3b281996bc7b5e..a50ea79522f85af88f82460f979339ce93d7fbce 100644 (file)
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -383,6 +383,13 @@ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);
 void arch_teardown_msi_irq(unsigned int irq);
 int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type);
 void arch_teardown_msi_irqs(struct pci_dev *dev);
+#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */
+
+/*
+ * Xen uses non-default msi_domain_ops and hence needs a way to populate sysfs
+ * entries of MSI IRQs.
+ */
+#if defined(CONFIG_PCI_XEN) || defined(CONFIG_PCI_MSI_ARCH_FALLBACKS)
 #ifdef CONFIG_SYSFS
 int msi_device_populate_sysfs(struct device *dev);
 void msi_device_destroy_sysfs(struct device *dev);
@@ -390,7 +397,7 @@ void msi_device_destroy_sysfs(struct device *dev);
 static inline int msi_device_populate_sysfs(struct device *dev) { return 0; }
 static inline void msi_device_destroy_sysfs(struct device *dev) { }
 #endif /* !CONFIG_SYSFS */
-#endif /* CONFIG_PCI_MSI_ARCH_FALLBACKS */
+#endif /* CONFIG_PCI_XEN || CONFIG_PCI_MSI_ARCH_FALLBACKS */
 
 /*
  * The restore hook is still available even for fully irq domain based

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 7a97bcb086bf39e92f9ac0cf6fb29c946631d2aa..b4c31a5c11473cc61ed6b12f57e90ca1c8bedc0e 100644 (file)
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -542,7 +542,7 @@ static int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc)
        return ret;
 }
 
-#ifdef CONFIG_PCI_MSI_ARCH_FALLBACKS
+#if defined(CONFIG_PCI_MSI_ARCH_FALLBACKS) || defined(CONFIG_PCI_XEN)
 /**
  * msi_device_populate_sysfs - Populate msi_irqs sysfs entries for a device
  * @dev:       The device (PCI, platform etc) which will get sysfs entries
@@ -574,7 +574,7 @@ void msi_device_destroy_sysfs(struct device *dev)
        msi_for_each_desc(desc, dev, MSI_DESC_ALL)
                msi_sysfs_remove_desc(dev, desc);
 }
-#endif /* CONFIG_PCI_MSI_ARCH_FALLBACK */
+#endif /* CONFIG_PCI_MSI_ARCH_FALLBACK || CONFIG_PCI_XEN */
 #else /* CONFIG_SYSFS */
 static inline int msi_sysfs_create_group(struct device *dev) { return 0; }
 static inline int msi_sysfs_populate_desc(struct device *dev, struct msi_desc *desc) { return 0; }