[RFC KERNEL PATCH v7 1/2] xen/pvh: Setup gsi for passthrough device

[Jiqian Chen <Jiqian.Chen@xxxxxxx>]

In PVH dom0, the gsis don't get registered, but the gsi of
a passthrough device must be configured for it to be able to be
mapped into a domU.

When assign a device to passthrough, proactively setup the gsi
of the device during that process.

Co-developed-by: Huang Rui <ray.huang@xxxxxxx>
Signed-off-by: Jiqian Chen <Jiqian.Chen@xxxxxxx>
Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 arch/x86/xen/enlighten_pvh.c       | 21 +++++++++++++
 drivers/acpi/pci_irq.c             |  2 +-
 drivers/xen/acpi.c                 | 50 ++++++++++++++++++++++++++++++
 drivers/xen/xen-pciback/pci_stub.c | 21 +++++++++++++
 include/linux/acpi.h               |  1 +
 include/xen/acpi.h                 | 10 ++++++
 6 files changed, 104 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
index 27a2a02ef8fb..711cdcbc6916 100644
--- a/arch/x86/xen/enlighten_pvh.c
+++ b/arch/x86/xen/enlighten_pvh.c
@@ -4,6 +4,7 @@
 #include <linux/mm.h>
 
 #include <xen/hvc-console.h>
+#include <xen/acpi.h>
 
 #include <asm/bootparam.h>
 #include <asm/io_apic.h>
@@ -27,6 +28,26 @@
 bool __ro_after_init xen_pvh;
 EXPORT_SYMBOL_GPL(xen_pvh);
 
+int xen_pvh_setup_gsi(int gsi, int trigger, int polarity)
+{
+       int ret;
+       struct physdev_setup_gsi setup_gsi;
+
+       setup_gsi.gsi = gsi;
+       setup_gsi.triggering = (trigger == ACPI_EDGE_SENSITIVE ? 0 : 1);
+       setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
+
+       ret = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
+       if (ret == -EEXIST) {
+               xen_raw_printk("Already setup the GSI :%d\n", gsi);
+               ret = 0;
+       } else if (ret)
+               xen_raw_printk("Fail to setup GSI (%d)!\n", gsi);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(xen_pvh_setup_gsi);
+
 void __init xen_pvh_init(struct boot_params *boot_params)
 {
        u32 msr;
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index ff30ceca2203..630fe0a34bc6 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -288,7 +288,7 @@ static int acpi_reroute_boot_interrupt(struct pci_dev *dev,
 }
 #endif /* CONFIG_X86_IO_APIC */
 
-static struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
+struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin)
 {
        struct acpi_prt_entry *entry = NULL;
        struct pci_dev *bridge;
diff --git a/drivers/xen/acpi.c b/drivers/xen/acpi.c
index 6893c79fd2a1..9e2096524fbc 100644
--- a/drivers/xen/acpi.c
+++ b/drivers/xen/acpi.c
@@ -30,6 +30,7 @@
  * IN THE SOFTWARE.
  */
 
+#include <linux/pci.h>
 #include <xen/acpi.h>
 #include <xen/interface/platform.h>
 #include <asm/xen/hypercall.h>
@@ -75,3 +76,52 @@ int xen_acpi_notify_hypervisor_extended_sleep(u8 sleep_state,
        return xen_acpi_notify_hypervisor_state(sleep_state, val_a,
                                                val_b, true);
 }
+
+struct acpi_prt_entry {
+       struct acpi_pci_id      id;
+       u8                      pin;
+       acpi_handle             link;
+       u32                     index;
+};
+
+int xen_acpi_get_gsi_info(struct pci_dev *dev,
+                                                 int *gsi_out,
+                                                 int *trigger_out,
+                                                 int *polarity_out)
+{
+       int gsi;
+       u8 pin;
+       struct acpi_prt_entry *entry;
+       int trigger = ACPI_LEVEL_SENSITIVE;
+       int polarity = acpi_irq_model == ACPI_IRQ_MODEL_GIC ?
+                                     ACPI_ACTIVE_HIGH : ACPI_ACTIVE_LOW;
+
+       if (!dev || !gsi_out || !trigger_out || !polarity_out)
+               return -EINVAL;
+
+       pin = dev->pin;
+       if (!pin)
+               return -EINVAL;
+
+       entry = acpi_pci_irq_lookup(dev, pin);
+       if (entry) {
+               if (entry->link)
+                       gsi = acpi_pci_link_allocate_irq(entry->link,
+                                                        entry->index,
+                                                        &trigger, &polarity,
+                                                        NULL);
+               else
+                       gsi = entry->index;
+       } else
+               gsi = -1;
+
+       if (gsi < 0)
+               return -EINVAL;
+
+       *gsi_out = gsi;
+       *trigger_out = trigger;
+       *polarity_out = polarity;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(xen_acpi_get_gsi_info);
diff --git a/drivers/xen/xen-pciback/pci_stub.c 
b/drivers/xen/xen-pciback/pci_stub.c
index 46c40ec8a18e..2b90d832d0a7 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -21,6 +21,9 @@
 #include <xen/events.h>
 #include <xen/pci.h>
 #include <xen/xen.h>
+#ifdef CONFIG_ACPI
+#include <xen/acpi.h>
+#endif
 #include <asm/xen/hypervisor.h>
 #include <xen/interface/physdev.h>
 #include "pciback.h"
@@ -367,6 +370,9 @@ static int pcistub_match(struct pci_dev *dev)
 static int pcistub_init_device(struct pci_dev *dev)
 {
        struct xen_pcibk_dev_data *dev_data;
+#ifdef CONFIG_ACPI
+       int gsi, trigger, polarity;
+#endif
        int err = 0;
 
        dev_dbg(&dev->dev, "initializing...\n");
@@ -435,6 +441,21 @@ static int pcistub_init_device(struct pci_dev *dev)
                        goto config_release;
                pci_restore_state(dev);
        }
+
+#ifdef CONFIG_ACPI
+       err = xen_acpi_get_gsi_info(dev, &gsi, &trigger, &polarity);
+       if (err) {
+               dev_err(&dev->dev, "Fail to get gsi info!\n");
+               goto config_release;
+       }
+
+       if (xen_initial_domain() && xen_pvh_domain()) {
+               err = xen_pvh_setup_gsi(gsi, trigger, polarity);
+               if (err)
+                       goto config_release;
+       }
+#endif
+
        /* Now disable the device (this also ensures some private device
         * data is setup before we export)
         */
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 34829f2c517a..f8690b02bba4 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -361,6 +361,7 @@ void acpi_unregister_gsi (u32 gsi);
 
 struct pci_dev;
 
+struct acpi_prt_entry *acpi_pci_irq_lookup(struct pci_dev *dev, int pin);
 int acpi_pci_irq_enable (struct pci_dev *dev);
 void acpi_penalize_isa_irq(int irq, int active);
 bool acpi_isa_irq_available(int irq);
diff --git a/include/xen/acpi.h b/include/xen/acpi.h
index b1e11863144d..9b50027113f3 100644
--- a/include/xen/acpi.h
+++ b/include/xen/acpi.h
@@ -67,10 +67,20 @@ static inline void xen_acpi_sleep_register(void)
                acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel;
        }
 }
+int xen_pvh_setup_gsi(int gsi, int trigger, int polarity);
 #else
 static inline void xen_acpi_sleep_register(void)
 {
 }
+
+static inline int xen_pvh_setup_gsi(int gsi, int trigger, int polarity)
+{
+       return -1;
+}
 #endif
 
+int xen_acpi_get_gsi_info(struct pci_dev *dev,
+                                                 int *gsi_out,
+                                                 int *trigger_out,
+                                                 int *polarity_out);
 #endif /* _XEN_ACPI_H */
-- 
2.34.1