From aae251a380fe4741594368e0d7836a082b17ae3e Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 4 Apr 2025 12:38:21 -0700 Subject: [PATCH] iommu/amd: WARN if KVM attempts to set vCPU affinity without posted intrrupts WARN if KVM attempts to set vCPU affinity when posted interrupts aren't enabled, as KVM shouldn't try to enable posting when they're unsupported, and the IOMMU driver darn well should only advertise posting support when AMD_IOMMU_GUEST_IR_VAPIC() is true. Note, KVM consumes is_guest_mode only on success. Signed-off-by: Sean Christopherson Message-ID: <20250404193923.1413163-7-seanjc@google.com> Signed-off-by: Paolo Bonzini --- drivers/iommu/amd/iommu.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 00965518b802..f34209b08b4c 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -3869,6 +3869,9 @@ static int amd_ir_set_vcpu_affinity(struct irq_data *data, void *vcpu_info) struct irq_2_irte *irte_info = &ir_data->irq_2_irte; struct iommu_dev_data *dev_data; + if (WARN_ON_ONCE(!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))) + return -EINVAL; + if (ir_data->iommu == NULL) return -EINVAL; @@ -3884,16 +3887,6 @@ static int amd_ir_set_vcpu_affinity(struct irq_data *data, void *vcpu_info) ir_data->cfg = irqd_cfg(data); pi_data->ir_data = ir_data; - /* Note: - * SVM tries to set up for VAPIC mode, but we are in - * legacy mode. So, we force legacy mode instead. - */ - if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir)) { - pr_debug("%s: Fall back to using intr legacy remap\n", - __func__); - pi_data->is_guest_mode = false; - } - pi_data->prev_ga_tag = ir_data->cached_ga_tag; if (pi_data->is_guest_mode) { ir_data->ga_root_ptr = (pi_data->base >> 12);