From fea858dc5d901626e5d794037b5bff9f59b9ded7 Mon Sep 17 00:00:00 2001 From: Nuno Das Neves Date: Thu, 17 Nov 2022 12:11:39 -0800 Subject: iommu/hyper-v: Allow hyperv irq remapping without x2apic 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 Reviewed-by: Tianyu Lan Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/1668715899-8971-1-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu --- drivers/iommu/Kconfig | 6 +++--- drivers/iommu/hyperv-iommu.c | 11 ++++++++--- 2 files changed, 11 insertions(+), 6 deletions(-) (limited to 'drivers/iommu') 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..8302db7f783e 100644 --- a/drivers/iommu/hyperv-iommu.c +++ b/drivers/iommu/hyperv-iommu.c @@ -122,9 +122,12 @@ static int __init hyperv_prepare_irq_remapping(void) const char *name; const struct irq_domain_ops *ops; + /* + * For a Hyper-V root partition, ms_hyperv_msi_ext_dest_id() + * will always return false. + */ 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 +173,9 @@ 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 = { -- cgit v1.2.3