Commit aae251a3 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

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: default avatarSean Christopherson <seanjc@google.com>
Message-ID: <20250404193923.1413163-7-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 07172206

drivers/iommu/amd/iommu.c

+3 −10
Original line number Diff line number Diff line
@@ -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);