There are several functions involved for performing the functionality
of evtchn_do_upcall():

- __xen_evtchn_do_upcall() doing the real work
- xen_hvm_evtchn_do_upcall() just being a wrapper for
  __xen_evtchn_do_upcall(), exposed for external callers
- xen_evtchn_do_upcall() calling __xen_evtchn_do_upcall(), too, but
  without any user

Simplify this maze by:

- removing the unused xen_evtchn_do_upcall()
- removing xen_hvm_evtchn_do_upcall() as the only left caller of
  __xen_evtchn_do_upcall(), while renaming __xen_evtchn_do_upcall() to
  xen_evtchn_do_upcall()

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/entry/common.c          |  2 +-
 arch/x86/xen/enlighten.c         |  2 +-
 arch/x86/xen/enlighten_hvm.c     |  2 +-
 drivers/xen/events/events_base.c | 21 ++-------------------
 drivers/xen/platform-pci.c       |  2 +-
 include/xen/events.h             |  3 +--
 6 files changed, 7 insertions(+), 25 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 6c2826417b33..93c60c0c9d4a 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -294,7 +294,7 @@ static void __xen_pv_evtchn_do_upcall(struct pt_regs *regs)
 
 	inc_irq_stat(irq_hv_callback_count);
 
-	xen_hvm_evtchn_do_upcall();
+	xen_evtchn_do_upcall();
 
 	set_irq_regs(old_regs);
 }
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index b8db2148c07d..0337392a3121 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -32,7 +32,7 @@ EXPORT_SYMBOL_GPL(hypercall_page);
  * &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info
  * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info
  * but during boot it is switched to point to xen_vcpu_info.
- * The pointer is used in __xen_evtchn_do_upcall to acknowledge pending events.
+ * The pointer is used in xen_evtchn_do_upcall to acknowledge pending events.
  */
 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
 DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info);
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index a6820ca940bf..fbf37ae825bf 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -136,7 +136,7 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback)
 
 	inc_irq_stat(irq_hv_callback_count);
 
-	xen_hvm_evtchn_do_upcall();
+	xen_evtchn_do_upcall();
 
 	set_irq_regs(old_regs);
 }
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index 3bdd5b59661d..0bb86e6c4d0a 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -1704,7 +1704,7 @@ void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
 	generic_handle_irq(irq);
 }
 
-static int __xen_evtchn_do_upcall(void)
+int xen_evtchn_do_upcall(void)
 {
 	struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
 	int ret = vcpu_info->evtchn_upcall_pending ? IRQ_HANDLED : IRQ_NONE;
@@ -1735,24 +1735,7 @@ static int __xen_evtchn_do_upcall(void)
 
 	return ret;
 }
-
-void xen_evtchn_do_upcall(struct pt_regs *regs)
-{
-	struct pt_regs *old_regs = set_irq_regs(regs);
-
-	irq_enter();
-
-	__xen_evtchn_do_upcall();
-
-	irq_exit();
-	set_irq_regs(old_regs);
-}
-
-int xen_hvm_evtchn_do_upcall(void)
-{
-	return __xen_evtchn_do_upcall();
-}
-EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
+EXPORT_SYMBOL_GPL(xen_evtchn_do_upcall);
 
 /* Rebind a new event channel to an existing irq. */
 void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index fcc819131572..544d3f9010b9 100644
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -64,7 +64,7 @@ static uint64_t get_callback_via(struct pci_dev *pdev)
 
 static irqreturn_t do_hvm_evtchn_intr(int irq, void *dev_id)
 {
-	return xen_hvm_evtchn_do_upcall();
+	return xen_evtchn_do_upcall();
 }
 
 static int xen_allocate_irq(struct pci_dev *pdev)
diff --git a/include/xen/events.h b/include/xen/events.h
index 95970a2f7695..8f62d15eef90 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -106,8 +106,7 @@ int irq_from_virq(unsigned int cpu, unsigned int virq);
 evtchn_port_t evtchn_from_irq(unsigned irq);
 
 int xen_set_callback_via(uint64_t via);
-void xen_evtchn_do_upcall(struct pt_regs *regs);
-int xen_hvm_evtchn_do_upcall(void);
+int xen_evtchn_do_upcall(void);
 
 /* Bind a pirq for a physical interrupt to an irq. */
 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
-- 
2.35.3

On Thu, Aug 24 2023 at 17:41, Juergen Gross wrote:
> There are several functions involved for performing the functionality
> of evtchn_do_upcall():
>
> - __xen_evtchn_do_upcall() doing the real work
> - xen_hvm_evtchn_do_upcall() just being a wrapper for
>   __xen_evtchn_do_upcall(), exposed for external callers
> - xen_evtchn_do_upcall() calling __xen_evtchn_do_upcall(), too, but
>   without any user
>
> Simplify this maze by:
>
> - removing the unused xen_evtchn_do_upcall()
> - removing xen_hvm_evtchn_do_upcall() as the only left caller of
>   __xen_evtchn_do_upcall(), while renaming __xen_evtchn_do_upcall() to
>   xen_evtchn_do_upcall()
>
> Signed-off-by: Juergen Gross <jgross@suse.com>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

On 8/24/23 11:41 AM, Juergen Gross wrote:
> There are several functions involved for performing the functionality
> of evtchn_do_upcall():
> 
> - __xen_evtchn_do_upcall() doing the real work
> - xen_hvm_evtchn_do_upcall() just being a wrapper for
>    __xen_evtchn_do_upcall(), exposed for external callers
> - xen_evtchn_do_upcall() calling __xen_evtchn_do_upcall(), too, but
>    without any user
> 
> Simplify this maze by:
> 
> - removing the unused xen_evtchn_do_upcall()
> - removing xen_hvm_evtchn_do_upcall() as the only left caller of
>    __xen_evtchn_do_upcall(), while renaming __xen_evtchn_do_upcall() to
>    xen_evtchn_do_upcall()
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>