Messages in this thread | | | Subject | Re: [patch RFC 23/38] x86/xen: Rework MSI teardown | From | Jürgen Groß <> | Date | Mon, 24 Aug 2020 07:09:35 +0200 |
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On 21.08.20 02:24, Thomas Gleixner wrote: > X86 cannot store the irq domain pointer in struct device without breaking > XEN because the irq domain pointer takes precedence over arch_*_msi_irqs() > fallbacks. > > XENs MSI teardown relies on default_teardown_msi_irqs() which invokes > arch_teardown_msi_irq(). default_teardown_msi_irqs() is a trivial iterator > over the msi entries associated to a device. > > Implement this loop in xen_teardown_msi_irqs() to prepare for removal of > the fallbacks for X86. > > This is a preparatory step to wrap XEN MSI alloc/free into a irq domain > which in turn allows to store the irq domain pointer in struct device and > to use the irq domain functions directly. > > Signed-off-by: Thomas Gleixner<tglx@linutronix.de> > --- > arch/x86/pci/xen.c | 23 ++++++++++++++++++----- > 1 file changed, 18 insertions(+), 5 deletions(-) > > --- a/arch/x86/pci/xen.c > +++ b/arch/x86/pci/xen.c > @@ -376,20 +376,31 @@ static void xen_initdom_restore_msi_irqs > static void xen_teardown_msi_irqs(struct pci_dev *dev) > { > struct msi_desc *msidesc; > + int i; > + > + for_each_pci_msi_entry(msidesc, dev) { > + if (msidesc->irq) { > + for (i = 0; i < msidesc->nvec_used; i++) > + xen_destroy_irq(msidesc->irq + i); > + } > + } > +} > + > +static void xen_pv_teardown_msi_irqs(struct pci_dev *dev) > +{ > + struct msi_desc *msidesc = first_pci_msi_entry(dev); > > - msidesc = first_pci_msi_entry(dev); > if (msidesc->msi_attrib.is_msix) > xen_pci_frontend_disable_msix(dev); > else > xen_pci_frontend_disable_msi(dev); > > - /* Free the IRQ's and the msidesc using the generic code. */ > - default_teardown_msi_irqs(dev); > + xen_teardown_msi_irqs(dev); > } > > static void xen_teardown_msi_irq(unsigned int irq) > { > - xen_destroy_irq(irq); > + WARN_ON_ONCE(1); > } > > #endif > @@ -412,7 +423,7 @@ int __init pci_xen_init(void) > #ifdef CONFIG_PCI_MSI > x86_msi.setup_msi_irqs = xen_setup_msi_irqs; > x86_msi.teardown_msi_irq = xen_teardown_msi_irq; > - x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs; > + x86_msi.teardown_msi_irqs = xen_pv_teardown_msi_irqs; > pci_msi_ignore_mask = 1; > #endif > return 0; > @@ -436,6 +447,7 @@ static void __init xen_hvm_msi_init(void > } > > x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs; > + x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs; > x86_msi.teardown_msi_irq = xen_teardown_msi_irq; > } > #endif > @@ -472,6 +484,7 @@ int __init pci_xen_initial_domain(void) > #ifdef CONFIG_PCI_MSI > x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs; > x86_msi.teardown_msi_irq = xen_teardown_msi_irq; > + x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
This should be xen_pv_teardown_msi_irqs, as pci_xen_initial_domain() is called only for the pv initial domain case today.
> x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs; > pci_msi_ignore_mask = 1; > #endif >
Juergen
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