On 03/10/2014 04:46 PM, Gavin Shan wrote: > The problem is specific to the case of BIST reset issued to IPR > adapter on the guest side. The IPR driver calls pci_save_state(), > issues BIST reset and then pci_restore_state(). The issued BIST > cleans out MSIx table and pci_restore_state() doesn't restore > the MSIx table as expected. Eventually, MSIx messages with all > zeros are sent and causes EEH error on Power platform. > > The patch fixes it by writing MSIx message to MSIx table before > reenabling the individual interrupts in the following path: > > qemu/hw/pci/msix.c::msix_table_mmio_write > msix_handle_mask_update > msix_fire_vector_notifier > qemu/hw/misc/vfio.c::vfio_msix_vector_use > vfio_msix_vector_do_use > > IOCTL Command VFIO_DEVICE_SET_IRQS to VFIO-PCI > vfio/pci/vfio_pci.c::vfio_pci_ioctl > vfio/pci/vfio_pci_intrs.c::vfio_pci_set_irqs_ioctl > vfio_pci_set_msi_trigger > vfio_msi_set_block > vfio_msi_set_vector_signal > > Reported-by: Wen Xiong <wenxiong@xxxxxxxxxx> > Signed-off-by: Gavin Shan <shangw@xxxxxxxxxxxxxxxxxx> > --- > drivers/vfio/pci/vfio_pci_intrs.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c > index 2103576..83e0638 100644 > --- a/drivers/vfio/pci/vfio_pci_intrs.c > +++ b/drivers/vfio/pci/vfio_pci_intrs.c > @@ -17,6 +17,7 @@ > #include <linux/interrupt.h> > #include <linux/eventfd.h> > #include <linux/pci.h> > +#include <linux/msi.h> > #include <linux/file.h> > #include <linux/poll.h> > #include <linux/vfio.h> > @@ -517,6 +518,7 @@ static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev, > struct pci_dev *pdev = vdev->pdev; > int irq = msix ? vdev->msix[vector].vector : pdev->irq + vector; > char *name = msix ? "vfio-msix" : "vfio-msi"; > + struct msi_msg msg; > struct eventfd_ctx *trigger; > int ret; > > @@ -544,6 +546,15 @@ static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev, > return PTR_ERR(trigger); > } > > + /* We possiblly lose the MSI/MSIx message in some cases, one > + * of which is pci_save_state(), BIST reset and pci_restore_state() > + * for IPR adapter. The BIST reset cleans out MSIx table and we > + * don't have chance to restore it. Here, we have the trick to > + * restore it before enabling individual interrupts. For MSI messages, > + * it's harmless to write them back. > + */ > + get_cached_msi_msg(irq, &msg); > + write_msi_msg(irq, &msg); > ret = request_irq(irq, vfio_msihandler, 0, > vdev->ctx[vector].name, trigger); > if (ret) { > This is missing to successfully compile VFIO as modules: diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 2c10752..80ba2e9 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -283,6 +283,7 @@ void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg) __get_cached_msi_msg(entry, msg); } +EXPORT_SYMBOL_GPL(get_cached_msi_msg); void __write_msi_msg(struct msi_desc *entry, struct msi_msg *msg) { @@ -327,6 +328,7 @@ void write_msi_msg(unsigned int irq, struct msi_msg *msg) __write_msi_msg(entry, msg); } +EXPORT_SYMBOL_GPL(write_msi_msg); static void free_msi_irqs(struct pci_dev *dev) { -- Alexey -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html