[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PVH]: Help: msi.c
On Fri, 14 Dec 2012, Mukesh Rathor wrote: > On Thu, 13 Dec 2012 14:25:16 +0000 > Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> wrote: > > > On Thu, 13 Dec 2012, Jan Beulich wrote: > > > >>> On 13.12.12 at 13:19, Stefano Stabellini > > > >>> <stefano.stabellini@xxxxxxxxxxxxx> > > > wrote: > > > > On Thu, 13 Dec 2012, Jan Beulich wrote: > > > >> >>> On 13.12.12 at 02:43, Mukesh Rathor > > > >> >>> <mukesh.rathor@xxxxxxxxxx> wrote: > > > > Actually I think that you might be right: just looking at the code it > > seems that the mask bits get written to the table once as part of the > > initialization process: > > > > pci_enable_msix -> msix_capability_init -> msix_program_entries > > > > Unfortunately msix_program_entries is called few lines after > > arch_setup_msi_irqs, where we call PHYSDEVOP_map_pirq to map the MSI > > as a pirq. > > However after that is done, all the masking/unmask is done via > > irq_mask that we handle properly masking/unmasking the corresponding > > event channels. > > > > > > Possible solutions on top of my head: > > > > - in msix_program_entries instead of writing to the table directly > > (__msix_mask_irq), call desc->irq_data.chip->irq_mask(); > > > > - replace msix_program_entries with arch_msix_program_entries, but it > > would probably be unpopular. > > > Can you or Jan or somebody please take that over? I can focus on other > PVH things then and try to get a patch in asap. The following patch moves the MSI-X masking before arch_setup_msi_irqs, that is when Linux calls PHYSDEVOP_map_pirq that is the hypercall that causes Xen to execute msix_capability_init. I don't have access to a machine with an MSI-X device right now so I have only tested the appended patch with MSI. --- diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index a825d78..ef73e80 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -652,11 +652,22 @@ static void msix_program_entries(struct pci_dev *dev, int i = 0; list_for_each_entry(entry, &dev->msi_list, list) { + entries[i].vector = entry->irq; + irq_set_msi_desc(entry->irq, entry); + i++; + } +} + +static void msix_mask_entries(struct pci_dev *dev, + struct msix_entry *entries) +{ + struct msi_desc *entry; + int i = 0; + + list_for_each_entry(entry, &dev->msi_list, list) { int offset = entries[i].entry * PCI_MSIX_ENTRY_SIZE + PCI_MSIX_ENTRY_VECTOR_CTRL; - entries[i].vector = entry->irq; - irq_set_msi_desc(entry->irq, entry); entry->masked = readl(entry->mask_base + offset); msix_mask_irq(entry, 1); i++; @@ -696,6 +707,8 @@ static int msix_capability_init(struct pci_dev *dev, if (ret) return ret; + msix_mask_entries(dev, entries); + ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX); if (ret) goto error; _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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