Commit a0bb51f2 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Thomas Gleixner
Browse files

x86/xen: Split HVM vector callback setup and interrupt gate allocation 



As a preparatory change for making alloc_intr_gate() __init split
xen_callback_vector() into callback vector setup via hypercall
(xen_setup_callback_vector()) and interrupt gate allocation
(xen_alloc_callback_vector()).

xen_setup_callback_vector() is being called twice: on init and upon
system resume from xen_hvm_post_suspend(). alloc_intr_gate() only
needs to be called once.

Suggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200428093824.1451532-2-vkuznets@redhat.com
parent fbaed278

arch/x86/xen/suspend_hvm.c

+1 −1
Original line number Diff line number Diff line
@@ -13,6 +13,6 @@ void xen_hvm_post_suspend(int suspend_cancelled) 
		xen_hvm_init_shared_info();

		xen_vcpu_restore();

	}

	xen_callback_vector();

	xen_setup_callback_vector();

	xen_unplug_emulated_devices();

}

arch/x86/xen/xen-ops.h

+1 −1
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ void xen_enable_sysenter(void); 
void xen_enable_syscall(void);

void xen_vcpu_restore(void);



void xen_callback_vector(void);

void xen_setup_callback_vector(void);

void xen_hvm_init_shared_info(void);

void xen_unplug_emulated_devices(void);

drivers/xen/events/events_base.c

+17 −11
Original line number Diff line number Diff line
@@ -1639,26 +1639,30 @@ EXPORT_SYMBOL_GPL(xen_set_callback_via); 
/* Vector callbacks are better than PCI interrupts to receive event

 * channel notifications because we can receive vector callbacks on any

 * vcpu and we don't need PCI support or APIC interactions. */

void xen_callback_vector(void)

void xen_setup_callback_vector(void)

{

	int rc;

	uint64_t callback_via;



	if (xen_have_vector_callback) {

		callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);

		rc = xen_set_callback_via(callback_via);

		if (rc) {

		if (xen_set_callback_via(callback_via)) {

			pr_err("Request for Xen HVM callback vector failed\n");

			xen_have_vector_callback = 0;

			return;

		}

		pr_info_once("Xen HVM callback vector for event delivery is enabled\n");

		alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,

				xen_hvm_callback_vector);

	}

}



static __init void xen_alloc_callback_vector(void)

{

	if (!xen_have_vector_callback)

		return;



	pr_info("Xen HVM callback vector for event delivery is enabled\n");

	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, xen_hvm_callback_vector);

}

#else

void xen_callback_vector(void) {}

void xen_setup_callback_vector(void) {}

static inline void xen_alloc_callback_vector(void) {}

#endif



#undef MODULE_PARAM_PREFIX
@@ -1692,8 +1696,10 @@ void __init xen_init_IRQ(void) 
		if (xen_initial_domain())

			pci_xen_initial_domain();

	}

	if (xen_feature(XENFEAT_hvm_callback_vector))

		xen_callback_vector();

	if (xen_feature(XENFEAT_hvm_callback_vector)) {

		xen_setup_callback_vector();

		xen_alloc_callback_vector();

	}



	if (xen_hvm_domain()) {

		native_init_IRQ();

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