Subject: [PATCH AUTOSEL 5.14 38/99] KVM: PPC: Book3S HV: XICS: Fix mapping of passthrough interrupts

From: Sasha Levin <[email-masked]>
Date: Thu, 9 Sep 2021 20:14:57 -0400

From: Cédric Le Goater <[email-masked]>

[ Upstream commit 1753081f2d445f9157550692fcc4221cd3ff0958 ]

PCI MSIs now live in an MSI domain but the underlying calls, which
will EOI the interrupt in real mode, need an HW IRQ number mapped in
the XICS IRQ domain. Grab it there.

Signed-off-by: Cédric Le Goater <[email-masked]>
Signed-off-by: Michael Ellerman <[email-masked]>
Link: https://lore.kernel.org/r/[email-masked]
Signed-off-by: Sasha Levin <[email-masked]>
---
 arch/powerpc/kvm/book3s_hv.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 085fb8ecbf68..1ca0a4f760bc 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -5328,6 +5328,7 @@ static int kvmppc_set_passthru_irq(struct kvm *kvm, int host_irq, int guest_gsi)
 	struct kvmppc_passthru_irqmap *pimap;
 	struct irq_chip *chip;
 	int i, rc = 0;
+	struct irq_data *host_data;
 
 	if (!kvm_irq_bypass)
 		return 1;
@@ -5392,7 +5393,14 @@ static int kvmppc_set_passthru_irq(struct kvm *kvm, int host_irq, int guest_gsi)
 	 * the KVM real mode handler.
 	 */
 	smp_wmb();
-	irq_map->r_hwirq = desc->irq_data.hwirq;
+
+	/*
+	 * The 'host_irq' number is mapped in the PCI-MSI domain but
+	 * the underlying calls, which will EOI the interrupt in real
+	 * mode, need an HW IRQ number mapped in the XICS IRQ domain.
+	 */
+	host_data = irq_domain_get_irq_data(irq_get_default_host(), host_irq);
+	irq_map->r_hwirq = (unsigned int)irqd_to_hwirq(host_data);
 
 	if (i == pimap->n_mapped)
 		pimap->n_mapped++;
@@ -5400,7 +5408,7 @@ static int kvmppc_set_passthru_irq(struct kvm *kvm, int host_irq, int guest_gsi)
 	if (xics_on_xive())
 		rc = kvmppc_xive_set_mapped(kvm, guest_gsi, desc);
 	else
-		kvmppc_xics_set_mapped(kvm, guest_gsi, desc->irq_data.hwirq);
+		kvmppc_xics_set_mapped(kvm, guest_gsi, irq_map->r_hwirq);
 	if (rc)
 		irq_map->r_hwirq = 0;
 
-- 
2.30.2