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 <[email protected]>
> Signed-off-by: Gavin Shan <[email protected]>
> ---
> 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
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