From 9c8e9c9681a0f3f1ae90a90230d059c7a1dece5a Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 4 Nov 2021 00:27:29 +0100 Subject: PCI/MSI: Move non-mask check back into low level accessors The recent rework of PCI/MSI[X] masking moved the non-mask checks from the low level accessors into the higher level mask/unmask functions. This missed the fact that these accessors can be invoked from other places as well. The missing checks break XEN-PV which sets pci_msi_ignore_mask and also violates the virtual MSIX and the msi_attrib.maskbit protections. Instead of sprinkling checks all over the place, lift them back into the low level accessor functions. To avoid checking three different conditions combine them into one property of msi_desc::msi_attrib. [ josef: Fixed the missed conversion in the core code ] Fixes: fcacdfbef5a1 ("PCI/MSI: Provide a new set of mask and unmask functions") Reported-by: Josef Johansson Signed-off-by: Thomas Gleixner Tested-by: Josef Johansson Cc: Bjorn Helgaas Cc: stable@vger.kernel.org --- include/linux/msi.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/msi.h b/include/linux/msi.h index 49cf6eb222e7..e616f94c7c58 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -148,7 +148,7 @@ struct msi_desc { u8 is_msix : 1; u8 multiple : 3; u8 multi_cap : 3; - u8 maskbit : 1; + u8 can_mask : 1; u8 is_64 : 1; u8 is_virtual : 1; u16 entry_nr; -- cgit v1.2.3 From 2226667a145db2e1f314d7f57fd644fe69863ab9 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 4 Nov 2021 18:01:29 +0000 Subject: PCI/MSI: Deal with devices lying about their MSI mask capability It appears that some devices are lying about their mask capability, pretending that they don't have it, while they actually do. The net result is that now that we don't enable MSIs on such endpoint. Add a new per-device flag to deal with this. Further patches will make use of it, sadly. Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Link: https://lore.kernel.org/r/20211104180130.3825416-2-maz@kernel.org Cc: Bjorn Helgaas --- drivers/pci/msi.c | 3 +++ include/linux/pci.h | 2 ++ 2 files changed, 5 insertions(+) (limited to 'include/linux') diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 6da791022d2e..70433013897b 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -477,6 +477,9 @@ msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd) goto out; pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control); + /* Lies, damned lies, and MSIs */ + if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING) + control |= PCI_MSI_FLAGS_MASKBIT; entry->msi_attrib.is_msix = 0; entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT); diff --git a/include/linux/pci.h b/include/linux/pci.h index c8afbee5da4b..d0dba7fd9848 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -233,6 +233,8 @@ enum pci_dev_flags { PCI_DEV_FLAGS_NO_FLR_RESET = (__force pci_dev_flags_t) (1 << 10), /* Don't use Relaxed Ordering for TLPs directed at this device */ PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 11), + /* Device does honor MSI masking despite saying otherwise */ + PCI_DEV_FLAGS_HAS_MSI_MASKING = (__force pci_dev_flags_t) (1 << 12), }; enum pci_irq_reroute_variant { -- cgit v1.2.3