xen: support GSI -> pirq remapping in PV on HVM guests
Disable pcifront when running on HVM: it is meant to be used with pv
guests that don't have PCI bus.
Use acpi_register_gsi_xen_hvm to remap GSIs into pirqs.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
index 449c82f..f89a42a 100644
--- a/arch/x86/include/asm/xen/pci.h
+++ b/arch/x86/include/asm/xen/pci.h
@@ -3,10 +3,15 @@
#if defined(CONFIG_PCI_XEN)
extern int __init pci_xen_init(void);
+extern int __init pci_xen_hvm_init(void);
#define pci_xen 1
#else
#define pci_xen 0
#define pci_xen_init (0)
+static inline int pci_xen_hvm_init(void)
+{
+ return -1;
+}
#endif
#if defined(CONFIG_PCI_MSI)
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 3a4ab0b..d5284c4 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -14,6 +14,7 @@
#include <asm/xen/hypervisor.h>
+#include <xen/features.h>
#include <xen/events.h>
#include <asm/xen/pci.h>
@@ -184,3 +185,18 @@
#endif
return 0;
}
+
+int __init pci_xen_hvm_init(void)
+{
+ if (!xen_feature(XENFEAT_hvm_pirqs))
+ return 0;
+
+#ifdef CONFIG_ACPI
+ /*
+ * We don't want to change the actual ACPI delivery model,
+ * just how GSIs get registered.
+ */
+ __acpi_register_gsi = acpi_register_gsi_xen_hvm;
+#endif
+ return 0;
+}
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 239b011..32269bc 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -623,7 +623,8 @@
/* If we are a PV guest, we don't have GSIs (no ACPI passed). Therefore
* we are using the !xen_initial_domain() to drop in the function.*/
- if (identity_mapped_irq(gsi) || !xen_initial_domain()) {
+ if (identity_mapped_irq(gsi) || (!xen_initial_domain() &&
+ xen_pv_domain())) {
irq = gsi;
irq_alloc_desc_at(irq, 0);
} else
@@ -1397,6 +1398,9 @@
if (xen_hvm_domain()) {
xen_callback_vector();
native_init_IRQ();
+ /* pci_xen_hvm_init must be called after native_init_IRQ so that
+ * __acpi_register_gsi can point at the right function */
+ pci_xen_hvm_init();
} else {
irq_ctx_init(smp_processor_id());
}
diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h
index 70d2563..b6ca39a 100644
--- a/include/xen/interface/features.h
+++ b/include/xen/interface/features.h
@@ -47,6 +47,9 @@
/* x86: pvclock algorithm is safe to use on HVM */
#define XENFEAT_hvm_safe_pvclock 9
+/* x86: pirq can be used by HVM guests */
+#define XENFEAT_hvm_pirqs 10
+
#define XENFEAT_NR_SUBMAPS 1
#endif /* __XEN_PUBLIC_FEATURES_H__ */