From c95a438d2c37748541b696053cd5c72042c838ad Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 19 Mar 2025 10:20:59 +0800 Subject: [PATCH] iommu/vt-d: Put IRTE back into posted MSI mode if vCPU posting is disabled commit 2454823e97a63d85a6b215905f71e5a06324eab7 upstream. Add a helper to take care of reconfiguring an IRTE to deliver IRQs to the host, i.e. not to a vCPU, and use the helper when an IRTE's vCPU affinity is nullified, i.e. when KVM puts an IRTE back into "host" mode. Because posted MSIs use an ephemeral IRTE, using modify_irte() puts the IRTE into full remapped mode, i.e. unintentionally disables posted MSIs on the IRQ. Fixes: ed1e48ea4370 ("iommu/vt-d: Enable posted mode for device MSIs") Cc: stable@vger.kernel.org Cc: Thomas Gleixner Cc: Jacob Pan Signed-off-by: Sean Christopherson Link: https://lore.kernel.org/r/20250315025135.2365846-2-seanjc@google.com Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/intel/irq_remapping.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/intel/irq_remapping.c b/drivers/iommu/intel/irq_remapping.c index 7a6d188e3bea0..6166ad999b0ee 100644 --- a/drivers/iommu/intel/irq_remapping.c +++ b/drivers/iommu/intel/irq_remapping.c @@ -1173,7 +1173,17 @@ static void intel_ir_reconfigure_irte_posted(struct irq_data *irqd) static inline void intel_ir_reconfigure_irte_posted(struct irq_data *irqd) {} #endif -static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force) +static void __intel_ir_reconfigure_irte(struct irq_data *irqd, bool force_host) +{ + struct intel_ir_data *ir_data = irqd->chip_data; + + if (ir_data->irq_2_iommu.posted_msi) + intel_ir_reconfigure_irte_posted(irqd); + else if (force_host || ir_data->irq_2_iommu.mode == IRQ_REMAPPING) + modify_irte(&ir_data->irq_2_iommu, &ir_data->irte_entry); +} + +static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force_host) { struct intel_ir_data *ir_data = irqd->chip_data; struct irte *irte = &ir_data->irte_entry; @@ -1186,10 +1196,7 @@ static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force) irte->vector = cfg->vector; irte->dest_id = IRTE_DEST(cfg->dest_apicid); - if (ir_data->irq_2_iommu.posted_msi) - intel_ir_reconfigure_irte_posted(irqd); - else if (force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING) - modify_irte(&ir_data->irq_2_iommu, irte); + __intel_ir_reconfigure_irte(irqd, force_host); } /* @@ -1244,7 +1251,7 @@ static int intel_ir_set_vcpu_affinity(struct irq_data *data, void *info) /* stop posting interrupts, back to the default mode */ if (!vcpu_pi_info) { - modify_irte(&ir_data->irq_2_iommu, &ir_data->irte_entry); + __intel_ir_reconfigure_irte(data, true); } else { struct irte irte_pi;