Commit 3ef5ba66 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

Merge branch kvm-arm64/debugfs-fixes into kvmarm-master/next 



* kvm-arm64/debugfs-fixes:
  : .
  : Cleanup of the debugfs iterator, which are way more complicated
  : than they ought to be, courtesy of Fuad Tabba. From the cover letter:
  :
  : "This series refactors the debugfs implementations for `idregs` and
  :  `vgic-state` to use standard `seq_file` iterator patterns.
  :
  :  The existing implementations relied on storing iterator state within
  :  global VM structures (`kvm_arch` and `vgic_dist`). This approach
  :  prevented concurrent reads of the debugfs files (returning -EBUSY) and
  :  created improper dependencies between transient file operations and
  :  long-lived VM state."
  : .
  KVM: arm64: Use standard seq_file iterator for vgic-debug debugfs
  KVM: arm64: Reimplement vgic-debug XArray iteration
  KVM: arm64: Use standard seq_file iterator for idregs debugfs

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parents 47e89feb fb21cb08

arch/arm64/include/asm/kvm_host.h

+0 −3
Original line number Diff line number Diff line
@@ -373,9 +373,6 @@ struct kvm_arch { 
	/* Maximum number of counters for the guest */

	u8 nr_pmu_counters;



	/* Iterator for idreg debugfs */

	u8	idreg_debugfs_iter;



	/* Hypercall features firmware registers' descriptor */

	struct kvm_smccc_features smccc_feat;

	struct maple_tree smccc_filter;

arch/arm64/kvm/sys_regs.c

+8 −42
Original line number Diff line number Diff line
@@ -4993,7 +4993,7 @@ static bool emulate_sys_reg(struct kvm_vcpu *vcpu, 
	return false;

}



static const struct sys_reg_desc *idregs_debug_find(struct kvm *kvm, u8 pos)

static const struct sys_reg_desc *idregs_debug_find(struct kvm *kvm, loff_t pos)

{

	unsigned long i, idreg_idx = 0;
@@ -5003,10 +5003,8 @@ static const struct sys_reg_desc *idregs_debug_find(struct kvm *kvm, u8 pos) 
		if (!is_vm_ftr_id_reg(reg_to_encoding(r)))

			continue;



		if (idreg_idx == pos)

		if (idreg_idx++ == pos)

			return r;



		idreg_idx++;

	}



	return NULL;
@@ -5015,23 +5013,11 @@ static const struct sys_reg_desc *idregs_debug_find(struct kvm *kvm, u8 pos) 
static void *idregs_debug_start(struct seq_file *s, loff_t *pos)

{

	struct kvm *kvm = s->private;

	u8 *iter;



	mutex_lock(&kvm->arch.config_lock);



	iter = &kvm->arch.idreg_debugfs_iter;

	if (test_bit(KVM_ARCH_FLAG_ID_REGS_INITIALIZED, &kvm->arch.flags) &&

	    *iter == (u8)~0) {

		*iter = *pos;

		if (!idregs_debug_find(kvm, *iter))

			iter = NULL;

	} else {

		iter = ERR_PTR(-EBUSY);

	}



	mutex_unlock(&kvm->arch.config_lock);

	if (!test_bit(KVM_ARCH_FLAG_ID_REGS_INITIALIZED, &kvm->arch.flags))

		return NULL;



	return iter;

	return (void *)idregs_debug_find(kvm, *pos);

}



static void *idregs_debug_next(struct seq_file *s, void *v, loff_t *pos)
@@ -5040,37 +5026,19 @@ static void *idregs_debug_next(struct seq_file *s, void *v, loff_t *pos) 


	(*pos)++;



	if (idregs_debug_find(kvm, kvm->arch.idreg_debugfs_iter + 1)) {

		kvm->arch.idreg_debugfs_iter++;



		return &kvm->arch.idreg_debugfs_iter;

	}



	return NULL;

	return (void *)idregs_debug_find(kvm, *pos);

}



static void idregs_debug_stop(struct seq_file *s, void *v)

{

	struct kvm *kvm = s->private;



	if (IS_ERR(v))

		return;



	mutex_lock(&kvm->arch.config_lock);



	kvm->arch.idreg_debugfs_iter = ~0;



	mutex_unlock(&kvm->arch.config_lock);

}



static int idregs_debug_show(struct seq_file *s, void *v)

{

	const struct sys_reg_desc *desc;

	const struct sys_reg_desc *desc = v;

	struct kvm *kvm = s->private;



	desc = idregs_debug_find(kvm, kvm->arch.idreg_debugfs_iter);



	if (!desc->name)

	if (!desc)

		return 0;



	seq_printf(s, "%20s:\t%016llx\n",
@@ -5090,8 +5058,6 @@ DEFINE_SEQ_ATTRIBUTE(idregs_debug); 


void kvm_sys_regs_create_debugfs(struct kvm *kvm)

{

	kvm->arch.idreg_debugfs_iter = ~0;



	debugfs_create_file("idregs", 0444, kvm->debugfs_dentry, kvm,

			    &idregs_debug_fops);

}

arch/arm64/kvm/vgic/vgic-debug.c

+32 −76
Original line number Diff line number Diff line
@@ -25,11 +25,9 @@ 
struct vgic_state_iter {

	int nr_cpus;

	int nr_spis;

	int nr_lpis;

	int dist_id;

	int vcpu_id;

	unsigned long intid;

	int lpi_idx;

};



static void iter_next(struct kvm *kvm, struct vgic_state_iter *iter)
@@ -45,13 +43,15 @@ static void iter_next(struct kvm *kvm, struct vgic_state_iter *iter) 
	 * Let the xarray drive the iterator after the last SPI, as the iterator

	 * has exhausted the sequentially-allocated INTID space.

	 */

	if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS - 1) &&

	    iter->nr_lpis) {

		if (iter->lpi_idx < iter->nr_lpis)

			xa_find_after(&dist->lpi_xa, &iter->intid,

				      VGIC_LPI_MAX_INTID,

				      LPI_XA_MARK_DEBUG_ITER);

		iter->lpi_idx++;

	if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS - 1)) {

		if (iter->intid == VGIC_LPI_MAX_INTID + 1)

			return;



		rcu_read_lock();

		if (!xa_find_after(&dist->lpi_xa, &iter->intid,

				   VGIC_LPI_MAX_INTID, XA_PRESENT))

			iter->intid = VGIC_LPI_MAX_INTID + 1;

		rcu_read_unlock();

		return;

	}
@@ -61,44 +61,21 @@ static void iter_next(struct kvm *kvm, struct vgic_state_iter *iter) 
		iter->intid = 0;

}



static int iter_mark_lpis(struct kvm *kvm)

static int vgic_count_lpis(struct kvm *kvm)

{

	struct vgic_dist *dist = &kvm->arch.vgic;

	unsigned long intid, flags;

	struct vgic_irq *irq;

	unsigned long intid;

	int nr_lpis = 0;



	xa_lock_irqsave(&dist->lpi_xa, flags);



	xa_for_each(&dist->lpi_xa, intid, irq) {

		if (!vgic_try_get_irq_ref(irq))

			continue;



		__xa_set_mark(&dist->lpi_xa, intid, LPI_XA_MARK_DEBUG_ITER);

	rcu_read_lock();

	xa_for_each(&dist->lpi_xa, intid, irq)

		nr_lpis++;

	}



	xa_unlock_irqrestore(&dist->lpi_xa, flags);

	rcu_read_unlock();



	return nr_lpis;

}



static void iter_unmark_lpis(struct kvm *kvm)

{

	struct vgic_dist *dist = &kvm->arch.vgic;

	unsigned long intid, flags;

	struct vgic_irq *irq;



	xa_for_each_marked(&dist->lpi_xa, intid, irq, LPI_XA_MARK_DEBUG_ITER) {

		xa_lock_irqsave(&dist->lpi_xa, flags);

		__xa_clear_mark(&dist->lpi_xa, intid, LPI_XA_MARK_DEBUG_ITER);

		xa_unlock_irqrestore(&dist->lpi_xa, flags);



		/* vgic_put_irq() expects to be called outside of the xa_lock */

		vgic_put_irq(kvm, irq);

	}

}



static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter,

		      loff_t pos)

{
@@ -108,8 +85,6 @@ static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter, 


	iter->nr_cpus = nr_cpus;

	iter->nr_spis = kvm->arch.vgic.nr_spis;

	if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)

		iter->nr_lpis = iter_mark_lpis(kvm);



	/* Fast forward to the right position if needed */

	while (pos--)
@@ -121,7 +96,7 @@ static bool end_of_vgic(struct vgic_state_iter *iter) 
	return iter->dist_id > 0 &&

		iter->vcpu_id == iter->nr_cpus &&

		iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS) &&

		(!iter->nr_lpis || iter->lpi_idx > iter->nr_lpis);

		iter->intid > VGIC_LPI_MAX_INTID;

}



static void *vgic_debug_start(struct seq_file *s, loff_t *pos)
@@ -129,72 +104,56 @@ static void *vgic_debug_start(struct seq_file *s, loff_t *pos) 
	struct kvm *kvm = s->private;

	struct vgic_state_iter *iter;



	mutex_lock(&kvm->arch.config_lock);

	iter = kvm->arch.vgic.iter;

	if (iter) {

		iter = ERR_PTR(-EBUSY);

		goto out;

	}



	iter = kmalloc(sizeof(*iter), GFP_KERNEL);

	if (!iter) {

		iter = ERR_PTR(-ENOMEM);

		goto out;

	}

	if (!iter)

		return ERR_PTR(-ENOMEM);



	iter_init(kvm, iter, *pos);

	kvm->arch.vgic.iter = iter;



	if (end_of_vgic(iter))

	if (end_of_vgic(iter)) {

		kfree(iter);

		iter = NULL;

out:

	mutex_unlock(&kvm->arch.config_lock);

	}



	return iter;

}



static void *vgic_debug_next(struct seq_file *s, void *v, loff_t *pos)

{

	struct kvm *kvm = s->private;

	struct vgic_state_iter *iter = kvm->arch.vgic.iter;

	struct vgic_state_iter *iter = v;



	++*pos;

	iter_next(kvm, iter);

	if (end_of_vgic(iter))

	if (end_of_vgic(iter)) {

		kfree(iter);

		iter = NULL;

	}

	return iter;

}



static void vgic_debug_stop(struct seq_file *s, void *v)

{

	struct kvm *kvm = s->private;

	struct vgic_state_iter *iter;

	struct vgic_state_iter *iter = v;



	/*

	 * If the seq file wasn't properly opened, there's nothing to clearn

	 * up.

	 */

	if (IS_ERR(v))

	if (IS_ERR_OR_NULL(v))

		return;



	mutex_lock(&kvm->arch.config_lock);

	iter = kvm->arch.vgic.iter;

	iter_unmark_lpis(kvm);

	kfree(iter);

	kvm->arch.vgic.iter = NULL;

	mutex_unlock(&kvm->arch.config_lock);

}



static void print_dist_state(struct seq_file *s, struct vgic_dist *dist,

			     struct vgic_state_iter *iter)

{

	bool v3 = dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;

	struct kvm *kvm = s->private;



	seq_printf(s, "Distributor\n");

	seq_printf(s, "===========\n");

	seq_printf(s, "vgic_model:\t%s\n", v3 ? "GICv3" : "GICv2");

	seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);

	if (v3)

		seq_printf(s, "nr_lpis:\t%d\n", iter->nr_lpis);

		seq_printf(s, "nr_lpis:\t%d\n", vgic_count_lpis(kvm));

	seq_printf(s, "enabled:\t%d\n", dist->enabled);

	seq_printf(s, "\n");
@@ -291,16 +250,13 @@ static int vgic_debug_show(struct seq_file *s, void *v) 
	if (iter->vcpu_id < iter->nr_cpus)

		vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);



	/*

	 * Expect this to succeed, as iter_mark_lpis() takes a reference on

	 * every LPI to be visited.

	 */

	if (iter->intid < VGIC_NR_PRIVATE_IRQS)

		irq = vgic_get_vcpu_irq(vcpu, iter->intid);

	else

		irq = vgic_get_irq(kvm, iter->intid);

	if (WARN_ON_ONCE(!irq))

		return -EINVAL;



	if (!irq)

		return 0;



	raw_spin_lock_irqsave(&irq->irq_lock, flags);

	print_irq_state(s, irq, vcpu);

include/kvm/arm_vgic.h

+0 −4
Original line number Diff line number Diff line
@@ -300,12 +300,8 @@ struct vgic_dist { 
	 */

	u64			propbaser;



#define LPI_XA_MARK_DEBUG_ITER	XA_MARK_0

	struct xarray		lpi_xa;



	/* used by vgic-debug */

	struct vgic_state_iter *iter;



	/*

	 * GICv4 ITS per-VM data, containing the IRQ domain, the VPE

	 * array, the property table pointer as well as allocation