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* [PATCH] x86/pci/xen: populate MSI sysfs entries
@ 2023-05-03 13:16 Maximilian Heyne
  2023-05-08 15:53 ` Juergen Gross
  2023-05-24 15:43 ` Maximilian Heyne
  0 siblings, 2 replies; 5+ messages in thread
From: Maximilian Heyne @ 2023-05-03 13:16 UTC (permalink / raw)
  Cc: Maximilian Heyne, Juergen Gross, Bjorn Helgaas, Thomas Gleixner,
	Ingo Molnar, Borislav Petkov, Dave Hansen, x86, H. Peter Anvin,
	Marc Zyngier, Kevin Tian, Jason Gunthorpe, Ashok Raj,
	Ahmed S. Darwish, Greg Kroah-Hartman, xen-devel, linux-pci,
	linux-kernel

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>
---
 arch/x86/pci/xen.c  | 8 +++++---
 include/linux/msi.h | 9 ++++++++-
 kernel/irq/msi.c    | 4 ++--
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 8babce71915f..014c508e914d 100644
--- 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 cdb14a1ef268..a50ea79522f8 100644
--- 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 7a97bcb086bf..b4c31a5c1147 100644
--- 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; }
-- 
2.39.2




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Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2023-05-03 13:16 [PATCH] x86/pci/xen: populate MSI sysfs entries Maximilian Heyne
2023-05-08 15:53 ` Juergen Gross
2023-05-24 15:43 ` Maximilian Heyne
2023-05-24 15:47   ` Juergen Gross
2023-05-24 16:00     ` Dave Hansen

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