diff options
| author | Dexuan Cui <decui@microsoft.com> | 2019-09-02 23:14:56 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2019-09-03 09:16:50 +0100 |
| commit | 711419e504ebd68c8f03656616829c8ad7829389 (patch) | |
| tree | c7f7e530bc5231b42678ded372058b87483003ad /kernel/irq | |
| parent | 2178add02238f8352f5b3294a79f4763183aade6 (diff) | |
| download | linux-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.c | 1 |
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); |