[PATCH v2 5/5] x86: virtio-mmio: support virtio-mmio with MSI for x86

[Zha Bin <zhabin@linux.alibaba.com>]

From: Liu Jiang <gerry@linux.alibaba.com>

virtio-mmio supports a generic MSI irq domain for all archs. This
patch adds the x86 architecture support.

Signed-off-by: Liu Jiang <gerry@linux.alibaba.com>
Co-developed-by: Zha Bin <zhabin@linux.alibaba.com>
Signed-off-by: Zha Bin <zhabin@linux.alibaba.com>
Co-developed-by: Jing Liu <jing2.liu@linux.intel.com>
Signed-off-by: Jing Liu <jing2.liu@linux.intel.com>
Co-developed-by: Chao Peng <chao.p.peng@linux.intel.com>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
---
 arch/x86/kernel/apic/msi.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
index 159bd0c..2fcd602 100644
--- a/arch/x86/kernel/apic/msi.c
+++ b/arch/x86/kernel/apic/msi.c
@@ -45,7 +45,11 @@ static void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg)
 		MSI_DATA_VECTOR(cfg->vector);
 }
 
-static void irq_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
+/*
+ * x86 PCI-MSI/HPET/DMAR related method.
+ * Also can be used as arch specific method for virtio-mmio MSI.
+ */
+void irq_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
 {
 	__irq_msi_compose_msg(irqd_cfg(data), msg);
 }
@@ -166,6 +170,11 @@ static void irq_msi_update_msg(struct irq_data *irqd, struct irq_cfg *cfg)
 	return ret;
 }
 
+struct irq_domain *arch_msi_root_irq_domain(void)
+{
+	return x86_vector_domain;
+}
+
 /*
  * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
  * which implement the MSI or MSI-X Capability Structure.
-- 
1.8.3.1