Re: [PATCH 04/13] pci: New pci_dma_quirk()
Alex, On Sat, May 12, 2012 at 6:55 AM, Alex Williamson alex.william...@redhat.com wrote: Integrating IOMMU groups more closely into the driver core allows us to more easily work around DMA quirks. The Ricoh multifunction controller is a favorite example of devices that are currently incompatible with IOMMU isolation as all the functions use the requestor ID of function 0 for DMA. Passing this device into pci_dma_quirk returns the PCI device to use for DMA. The IOMMU driver can then construct an IOMMU group including both devices. Please give some thought to the Marvell SATA controller quirk as well. Instead of multiple visible functions using the same requester ID of function 0, the Marvell device only makes function 0 visible, but uses the requestor ID of function 1 as well during DMA. See https://bugzilla.redhat.com/show_bug.cgi?id=757166 -- A. -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/13] pci: New pci_dma_quirk()
On Thu, 2012-05-17 at 15:19 +0800, Anonymous wrote: Alex, On Sat, May 12, 2012 at 6:55 AM, Alex Williamson alex.william...@redhat.com wrote: Integrating IOMMU groups more closely into the driver core allows us to more easily work around DMA quirks. The Ricoh multifunction controller is a favorite example of devices that are currently incompatible with IOMMU isolation as all the functions use the requestor ID of function 0 for DMA. Passing this device into pci_dma_quirk returns the PCI device to use for DMA. The IOMMU driver can then construct an IOMMU group including both devices. Please give some thought to the Marvell SATA controller quirk as well. Instead of multiple visible functions using the same requester ID of function 0, the Marvell device only makes function 0 visible, but uses the requestor ID of function 1 as well during DMA. See https://bugzilla.redhat.com/show_bug.cgi?id=757166 Wow. That one isn't quite as easy to deal with since there's no existing device in the kernel to point to. This comment might be on the right track: https://bugzilla.kernel.org/show_bug.cgi?id=42679#c11 Perhaps David Woodhouse can comment on support for phantom functions. If we had infrastructure for that it might be easy for the quirk to update the pci_dev struct, inserting a new phantom function. Otherwise we'd need to create a new device in the kernel for it. Thanks, Alex -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/13] pci: New pci_dma_quirk()
On Fri, May 11, 2012 at 04:55:55PM -0600, Alex Williamson wrote:
Integrating IOMMU groups more closely into the driver core allows
us to more easily work around DMA quirks. The Ricoh multifunction
controller is a favorite example of devices that are currently
incompatible with IOMMU isolation as all the functions use the
requestor ID of function 0 for DMA. Passing this device into
pci_dma_quirk returns the PCI device to use for DMA. The IOMMU
driver can then construct an IOMMU group including both devices.
Signed-off-by: Alex Williamson alex.william...@redhat.com
---
drivers/pci/quirks.c | 22 ++
include/linux/pci.h |2 ++
2 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 4bf7102..6f9f7f9 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3109,3 +3109,25 @@ int pci_dev_specific_reset(struct pci_dev *dev, int
probe)
return -ENOTTY;
}
+
+struct pci_dev *pci_dma_quirk(struct pci_dev *dev)
+{
+ struct pci_dev *dma_dev = dev;
+
+ /*
+ * https://bugzilla.redhat.com/show_bug.cgi?id=605888
+ *
+ * Some Ricoh devices use the function 0 source ID for DMA on
+ * other functions of a multifunction device. The DMA devices
+ * is therefore function 0, which will have implications of the
+ * iommu grouping of these devices.
+ */
+ if (dev-vendor == PCI_VENDOR_ID_RICOH
+ (dev-device == 0xe822 || dev-device == 0xe230 ||
+ dev-device == 0xe832 || dev-device == 0xe476)) {
+ dma_dev = pci_get_slot(dev-bus,
+PCI_DEVFN(PCI_SLOT(dev-devfn), 0));
+ }
Hrm. This seems like a very generic name for a function performing a
very specific test. We could well have devices with the same problem
in future, so shouldn't this be set up so the same quirk can be easily
added to new device ids without changing the function code itself.
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| _way_ _around_!
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Re: [PATCH 04/13] pci: New pci_dma_quirk()
On Thu, 2012-05-17 at 13:39 +1000, David Gibson wrote:
On Fri, May 11, 2012 at 04:55:55PM -0600, Alex Williamson wrote:
Integrating IOMMU groups more closely into the driver core allows
us to more easily work around DMA quirks. The Ricoh multifunction
controller is a favorite example of devices that are currently
incompatible with IOMMU isolation as all the functions use the
requestor ID of function 0 for DMA. Passing this device into
pci_dma_quirk returns the PCI device to use for DMA. The IOMMU
driver can then construct an IOMMU group including both devices.
Signed-off-by: Alex Williamson alex.william...@redhat.com
---
drivers/pci/quirks.c | 22 ++
include/linux/pci.h |2 ++
2 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 4bf7102..6f9f7f9 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3109,3 +3109,25 @@ int pci_dev_specific_reset(struct pci_dev *dev, int
probe)
return -ENOTTY;
}
+
+struct pci_dev *pci_dma_quirk(struct pci_dev *dev)
+{
+ struct pci_dev *dma_dev = dev;
+
+ /*
+* https://bugzilla.redhat.com/show_bug.cgi?id=605888
+*
+* Some Ricoh devices use the function 0 source ID for DMA on
+* other functions of a multifunction device. The DMA devices
+* is therefore function 0, which will have implications of the
+* iommu grouping of these devices.
+*/
+ if (dev-vendor == PCI_VENDOR_ID_RICOH
+ (dev-device == 0xe822 || dev-device == 0xe230 ||
+dev-device == 0xe832 || dev-device == 0xe476)) {
+ dma_dev = pci_get_slot(dev-bus,
+ PCI_DEVFN(PCI_SLOT(dev-devfn), 0));
+ }
Hrm. This seems like a very generic name for a function performing a
very specific test. We could well have devices with the same problem
in future, so shouldn't this be set up so the same quirk can be easily
added to new device ids without changing the function code itself.
I've since added a USB quirk here to group all the USB functions in a
slot. I'll take a closer look at the quirk helpers to see if anything
makes this easier, but I didn't see much point in spending a lot of time
over-optimizing this for 1 or 2 quirks that we can just step through in
a monolithic function. Thanks,
Alex
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