diff options
| -rw-r--r-- | xen/drivers/passthrough/amd/pci_amd_iommu.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c index 43175cd419..7251796330 100644 --- a/xen/drivers/passthrough/amd/pci_amd_iommu.c +++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c @@ -182,8 +182,19 @@ int __init amd_iov_detect(void) { if ( amd_iommu_perdev_intremap ) { - printk("AMD-Vi: Enabling per-device vector maps\n"); - opt_irq_vector_map = OPT_IRQ_VECTOR_MAP_PERDEV; + /* Per-device vector map logic is broken for devices with multiple + * MSI-X interrupts (and would also be for multiple MSI, if Xen + * supported it). + * + * Until this is fixed, use global vector tables as far as the irq + * logic is concerned to avoid the buggy behaviour of per-device + * maps in map_domain_pirq(), and use per-device tables as far as + * intremap code is concerned to avoid the security issue. + */ + printk(XENLOG_WARNING "AMD-Vi: per-device vector map logic is broken. " + "Using per-device-global maps instead until a fix is found.\n"); + + opt_irq_vector_map = OPT_IRQ_VECTOR_MAP_GLOBAL; } else { @@ -194,6 +205,10 @@ int __init amd_iov_detect(void) else { printk("AMD-Vi: Not overriding irq_vector_map setting\n"); + + if ( opt_irq_vector_map != OPT_IRQ_VECTOR_MAP_GLOBAL ) + printk(XENLOG_WARNING "AMD-Vi: per-device vector map logic is broken. " + "Use irq_vector_map=global to work around.\n"); } if ( !amd_iommu_perdev_intremap ) printk(XENLOG_WARNING "AMD-Vi: Using global interrupt remap table is not recommended (see XSA-36)!\n"); |