If x2apic is not available, hyperv-iommu skips remapping
irqs. This breaks root partition which always needs irqs
remapped.
Fix this by allowing irq remapping regardless of x2apic,
and change hyperv_enable_irq_remapping() to return
IRQ_REMAP_XAPIC_MODE in case x2apic is missing.
Tested with root and non-root hyperv partitions.
Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
---
drivers/iommu/Kconfig | 6 +++---
drivers/iommu/hyperv-iommu.c | 7 ++++---
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index dc5f7a156ff5..cf7433652db0 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -474,13 +474,13 @@ config QCOM_IOMMU
Support for IOMMU on certain Qualcomm SoCs.
config HYPERV_IOMMU
- bool "Hyper-V x2APIC IRQ Handling"
+ bool "Hyper-V IRQ Handling"
depends on HYPERV && X86
select IOMMU_API
default HYPERV
help
- Stub IOMMU driver to handle IRQs as to allow Hyper-V Linux
- guests to run with x2APIC mode enabled.
+ Stub IOMMU driver to handle IRQs to support Hyper-V Linux
+ guest and root partitions.
config VIRTIO_IOMMU
tristate "Virtio IOMMU driver"
diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-iommu.c
index e190bb8c225c..abd1826a9e63 100644
--- a/drivers/iommu/hyperv-iommu.c
+++ b/drivers/iommu/hyperv-iommu.c
@@ -123,8 +123,7 @@ static int __init hyperv_prepare_irq_remapping(void)
const struct irq_domain_ops *ops;
if (!hypervisor_is_type(X86_HYPER_MS_HYPERV) ||
- x86_init.hyper.msi_ext_dest_id() ||
- !x2apic_supported())
+ x86_init.hyper.msi_ext_dest_id())
return -ENODEV;
if (hv_root_partition) {
@@ -170,7 +169,9 @@ static int __init hyperv_prepare_irq_remapping(void)
static int __init hyperv_enable_irq_remapping(void)
{
- return IRQ_REMAP_X2APIC_MODE;
+ if (x2apic_supported())
+ return IRQ_REMAP_X2APIC_MODE;
+ return IRQ_REMAP_XAPIC_MODE;
}
struct irq_remap_ops hyperv_irq_remap_ops = {
--
2.25.1
