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authorDexuan Cui <decui@microsoft.com>2019-09-02 23:14:56 +0000
committerMarc Zyngier <maz@kernel.org>2019-09-03 09:16:50 +0100
commit711419e504ebd68c8f03656616829c8ad7829389 (patch)
treec7f7e530bc5231b42678ded372058b87483003ad /kernel/irq
parent2178add02238f8352f5b3294a79f4763183aade6 (diff)
downloadlinux-711419e504ebd68c8f03656616829c8ad7829389.tar.bz2
irqdomain: Add the missing assignment of domain->fwnode for named fwnode
Recently device pass-through stops working for Linux VM running on Hyper-V. git-bisect shows the regression is caused by the recent commit 467a3bb97432 ("PCI: hv: Allocate a named fwnode ..."), but the root cause is that the commit d59f6617eef0 forgets to set the domain->fwnode for IRQCHIP_FWNODE_NAMED*, and as a result: 1. The domain->fwnode remains to be NULL. 2. irq_find_matching_fwspec() returns NULL since "h->fwnode == fwnode" is false, and pci_set_bus_msi_domain() sets the Hyper-V PCI root bus's msi_domain to NULL. 3. When the device is added onto the root bus, the device's dev->msi_domain is set to NULL in pci_set_msi_domain(). 4. When a device driver tries to enable MSI-X, pci_msi_setup_msi_irqs() calls arch_setup_msi_irqs(), which uses the native MSI chip (i.e. arch/x86/kernel/apic/msi.c: pci_msi_controller) to set up the irqs, but actually pci_msi_setup_msi_irqs() is supposed to call msi_domain_alloc_irqs() with the hbus->irq_domain, which is created in hv_pcie_init_irq_domain() and is associated with the Hyper-V chip hv_msi_irq_chip. Consequently, the irq line is not properly set up, and the device driver can not receive any interrupt. Fixes: d59f6617eef0 ("genirq: Allow fwnode to carry name information only") Fixes: 467a3bb97432 ("PCI: hv: Allocate a named fwnode instead of an address-based one") Reported-by: Lili Deng <v-lide@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/PU1P153MB01694D9AF625AC335C600C5FBFBE0@PU1P153MB0169.APCP153.PROD.OUTLOOK.COM
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/irqdomain.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index e7bbab149750..132672b74e4b 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -149,6 +149,7 @@ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, int size,
switch (fwid->type) {
case IRQCHIP_FWNODE_NAMED:
case IRQCHIP_FWNODE_NAMED_ID:
+ domain->fwnode = fwnode;
domain->name = kstrdup(fwid->name, GFP_KERNEL);
if (!domain->name) {
kfree(domain);