Commit 9957c86d authored by Paul Mackerras's avatar Paul Mackerras Committed by Paolo Bonzini
Browse files

KVM: Move all accesses to kvm::irq_routing into irqchip.c 



Now that struct _irqfd does not keep a reference to storage pointed
to by the irq_routing field of struct kvm, we can move the statement
that updates it out from under the irqfds.lock and put it in
kvm_set_irq_routing() instead.  That means we then have to take a
srcu_read_lock on kvm->irq_srcu around the irqfd_update call in
kvm_irqfd_assign(), since holding the kvm->irqfds.lock no longer
ensures that that the routing can't change.

Combined with changing kvm_irq_map_gsi() and kvm_irq_map_chip_pin()
to take a struct kvm * argument instead of the pointer to the routing
table, this allows us to to move all references to kvm->irq_routing
into irqchip.c.  That in turn allows us to move the definition of the
kvm_irq_routing_table struct into irqchip.c as well.

Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
Tested-by: default avatarEric Auger <eric.auger@linaro.org>
Tested-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 8ba918d4

include/linux/kvm_host.h

+7 −28
Original line number Diff line number Diff line
@@ -325,24 +325,7 @@ struct kvm_kernel_irq_routing_entry { 
	struct hlist_node link;

};



#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING



struct kvm_irq_routing_table {

	int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];

	struct kvm_kernel_irq_routing_entry *rt_entries;

	u32 nr_rt_entries;

	/*

	 * Array indexed by gsi. Each entry contains list of irq chips

	 * the gsi is connected to.

	 */

	struct hlist_head map[0];

};



#else



struct kvm_irq_routing_table {};



#endif

struct kvm_irq_routing_table;



#ifndef KVM_PRIVATE_MEM_SLOTS

#define KVM_PRIVATE_MEM_SLOTS 0
@@ -401,8 +384,7 @@ struct kvm { 
	struct mutex irq_lock;

#ifdef CONFIG_HAVE_KVM_IRQCHIP

	/*

	 * Update side is protected by irq_lock and,

	 * if configured, irqfds.lock.

	 * Update side is protected by irq_lock.

	 */

	struct kvm_irq_routing_table __rcu *irq_routing;

	struct hlist_head mask_notifier_list;
@@ -752,10 +734,9 @@ void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq, 
void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,

			     bool mask);



int kvm_irq_map_gsi(struct kvm_kernel_irq_routing_entry *entries,

		    struct kvm_irq_routing_table *irq_rt, int gsi);

int kvm_irq_map_chip_pin(struct kvm_irq_routing_table *irq_rt,

			 unsigned irqchip, unsigned pin);

int kvm_irq_map_gsi(struct kvm *kvm,

		    struct kvm_kernel_irq_routing_entry *entries, int gsi);

int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin);



int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,

		bool line_status);
@@ -967,7 +948,7 @@ int kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args); 
#ifdef CONFIG_HAVE_KVM_IRQCHIP

int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args);

void kvm_irqfd_release(struct kvm *kvm);

void kvm_irq_routing_update(struct kvm *, struct kvm_irq_routing_table *);

void kvm_irq_routing_update(struct kvm *);

#else

static inline int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)

{
@@ -989,10 +970,8 @@ static inline int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args) 
static inline void kvm_irqfd_release(struct kvm *kvm) {}



#ifdef CONFIG_HAVE_KVM_IRQCHIP

static inline void kvm_irq_routing_update(struct kvm *kvm,

					  struct kvm_irq_routing_table *irq_rt)

static inline void kvm_irq_routing_update(struct kvm *kvm)

{

	rcu_assign_pointer(kvm->irq_routing, irq_rt);

}

#endif

virt/kvm/eventfd.c

+9 −13
Original line number Diff line number Diff line
@@ -278,14 +278,13 @@ irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, 
}



/* Must be called under irqfds.lock */

static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd,

			 struct kvm_irq_routing_table *irq_rt)

static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd)

{

	struct kvm_kernel_irq_routing_entry *e;

	struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];

	int i, n_entries;



	n_entries = kvm_irq_map_gsi(entries, irq_rt, irqfd->gsi);

	n_entries = kvm_irq_map_gsi(kvm, entries, irqfd->gsi);



	write_seqcount_begin(&irqfd->irq_entry_sc);
@@ -304,12 +303,12 @@ static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd, 
static int

kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)

{

	struct kvm_irq_routing_table *irq_rt;

	struct _irqfd *irqfd, *tmp;

	struct fd f;

	struct eventfd_ctx *eventfd = NULL, *resamplefd = NULL;

	int ret;

	unsigned int events;

	int idx;



	irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);

	if (!irqfd)
@@ -403,9 +402,9 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) 
		goto fail;

	}



	irq_rt = rcu_dereference_protected(kvm->irq_routing,

					   lockdep_is_held(&kvm->irqfds.lock));

	irqfd_update(kvm, irqfd, irq_rt);

	idx = srcu_read_lock(&kvm->irq_srcu);

	irqfd_update(kvm, irqfd);

	srcu_read_unlock(&kvm->irq_srcu, idx);



	list_add_tail(&irqfd->list, &kvm->irqfds.items);
@@ -539,20 +538,17 @@ kvm_irqfd_release(struct kvm *kvm) 
}



/*

 * Change irq_routing and irqfd.

 * Take note of a change in irq routing.

 * Caller must invoke synchronize_srcu(&kvm->irq_srcu) afterwards.

 */

void kvm_irq_routing_update(struct kvm *kvm,

			    struct kvm_irq_routing_table *irq_rt)

void kvm_irq_routing_update(struct kvm *kvm)

{

	struct _irqfd *irqfd;



	spin_lock_irq(&kvm->irqfds.lock);



	rcu_assign_pointer(kvm->irq_routing, irq_rt);



	list_for_each_entry(irqfd, &kvm->irqfds.items, list)

		irqfd_update(kvm, irqfd, irq_rt);

		irqfd_update(kvm, irqfd);



	spin_unlock_irq(&kvm->irqfds.lock);

}

virt/kvm/irq_comm.c

+2 −4
Original line number Diff line number Diff line
@@ -163,7 +163,6 @@ int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level) 
	struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];

	struct kvm_kernel_irq_routing_entry *e;

	int ret = -EINVAL;

	struct kvm_irq_routing_table *irq_rt;

	int idx;



	trace_kvm_set_irq(irq, level, irq_source_id);
@@ -177,8 +176,7 @@ int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level) 
	 * which is limited to 1:1 GSI mapping.

	 */

	idx = srcu_read_lock(&kvm->irq_srcu);

	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);

	if (kvm_irq_map_gsi(entries, irq_rt, irq) > 0) {

	if (kvm_irq_map_gsi(kvm, entries, irq) > 0) {

		e = &entries[0];

		if (likely(e->type == KVM_IRQ_ROUTING_MSI))

			ret = kvm_set_msi_inatomic(e, kvm);
@@ -264,7 +262,7 @@ void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin, 
	int idx, gsi;



	idx = srcu_read_lock(&kvm->irq_srcu);

	gsi = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu)->chip[irqchip][pin];

	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);

	if (gsi != -1)

		hlist_for_each_entry_rcu(kimn, &kvm->mask_notifier_list, link)

			if (kimn->irq == gsi)

virt/kvm/irqchip.c

+25 −14
Original line number Diff line number Diff line
@@ -31,12 +31,26 @@ 
#include <trace/events/kvm.h>

#include "irq.h"



int kvm_irq_map_gsi(struct kvm_kernel_irq_routing_entry *entries,

		    struct kvm_irq_routing_table *irq_rt, int gsi)

struct kvm_irq_routing_table {

	int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];

	struct kvm_kernel_irq_routing_entry *rt_entries;

	u32 nr_rt_entries;

	/*

	 * Array indexed by gsi. Each entry contains list of irq chips

	 * the gsi is connected to.

	 */

	struct hlist_head map[0];

};



int kvm_irq_map_gsi(struct kvm *kvm,

		    struct kvm_kernel_irq_routing_entry *entries, int gsi)

{

	struct kvm_irq_routing_table *irq_rt;

	struct kvm_kernel_irq_routing_entry *e;

	int n = 0;



	irq_rt = srcu_dereference_check(kvm->irq_routing, &kvm->irq_srcu,

					lockdep_is_held(&kvm->irq_lock));

	if (gsi < irq_rt->nr_rt_entries) {

		hlist_for_each_entry(e, &irq_rt->map[gsi], link) {

			entries[n] = *e;
@@ -47,21 +61,21 @@ int kvm_irq_map_gsi(struct kvm_kernel_irq_routing_entry *entries, 
	return n;

}



int kvm_irq_map_chip_pin(struct kvm_irq_routing_table *irq_rt,

			 unsigned irqchip, unsigned pin)

int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin)

{

	struct kvm_irq_routing_table *irq_rt;



	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);

	return irq_rt->chip[irqchip][pin];

}



bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)

{

	struct kvm_irq_routing_table *irq_rt;

	struct kvm_irq_ack_notifier *kian;

	int gsi, idx;



	idx = srcu_read_lock(&kvm->irq_srcu);

	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);

	gsi = kvm_irq_map_chip_pin(irq_rt, irqchip, pin);

	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);

	if (gsi != -1)

		hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,

					 link)
@@ -78,15 +92,13 @@ EXPORT_SYMBOL_GPL(kvm_irq_has_notifier); 


void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)

{

	struct kvm_irq_routing_table *irq_rt;

	struct kvm_irq_ack_notifier *kian;

	int gsi, idx;



	trace_kvm_ack_irq(irqchip, pin);



	idx = srcu_read_lock(&kvm->irq_srcu);

	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);

	gsi = kvm_irq_map_chip_pin(irq_rt, irqchip, pin);

	gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);

	if (gsi != -1)

		hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,

					 link)
@@ -143,7 +155,6 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level, 
{

	struct kvm_kernel_irq_routing_entry irq_set[KVM_NR_IRQCHIPS];

	int ret = -1, i, idx;

	struct kvm_irq_routing_table *irq_rt;



	trace_kvm_set_irq(irq, level, irq_source_id);
@@ -152,8 +163,7 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level, 
	 * writes to the unused one.

	 */

	idx = srcu_read_lock(&kvm->irq_srcu);

	irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);

	i = kvm_irq_map_gsi(irq_set, irq_rt, irq);

	i = kvm_irq_map_gsi(kvm, irq_set, irq);

	srcu_read_unlock(&kvm->irq_srcu, idx);



	while(i--) {
@@ -250,7 +260,8 @@ int kvm_set_irq_routing(struct kvm *kvm, 


	mutex_lock(&kvm->irq_lock);

	old = kvm->irq_routing;

	kvm_irq_routing_update(kvm, new);

	rcu_assign_pointer(kvm->irq_routing, new);

	kvm_irq_routing_update(kvm);

	mutex_unlock(&kvm->irq_lock);



	synchronize_srcu_expedited(&kvm->irq_srcu);

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