Re: [PATCH 20/20] KVM: arm64: Add debugfs file dumping computed RESx values

[Fuad Tabba <tabba@google.com>]

...

>
> Yes please. We might as well do the right thing, and I can fold that
> into my current series with you as a co-author.
>
> Thanks,

Here you go.

Cheers,
/fuad

---
 arch/arm64/include/asm/kvm_host.h |  1 -
 arch/arm64/kvm/sys_regs.c         | 42 +++++--------------------------
 2 files changed, 6 insertions(+), 37 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 54072f6ec9d4..c82b071ade2a 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -375,7 +375,6 @@ struct kvm_arch {
 
 	/* Iterator for idreg debugfs */
 	u8	idreg_debugfs_iter;
-	u16	sr_resx_iter;
 
 	/* Hypercall features firmware registers' descriptor */
 	struct kvm_smccc_features smccc_feat;
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index f3f92b489b58..d33c39ea8fad 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -5090,7 +5090,7 @@ static const struct seq_operations idregs_debug_sops = {
 
 DEFINE_SEQ_ATTRIBUTE(idregs_debug);
 
-static const struct sys_reg_desc *sr_resx_find(struct kvm *kvm, u16 pos)
+static const struct sys_reg_desc *sr_resx_find(struct kvm *kvm, loff_t pos)
 {
 	unsigned long i, sr_idx = 0;
 
@@ -5100,10 +5100,8 @@ static const struct sys_reg_desc *sr_resx_find(struct kvm *kvm, u16 pos)
 		if (r->reg < __SANITISED_REG_START__)
 			continue;
 
-		if (sr_idx == pos)
+		if (sr_idx++ == pos)
 			return r;
-
-		sr_idx++;
 	}
 
 	return NULL;
@@ -5112,22 +5110,11 @@ static const struct sys_reg_desc *sr_resx_find(struct kvm *kvm, u16 pos)
 static void *sr_resx_start(struct seq_file *s, loff_t *pos)
 {
 	struct kvm *kvm = s->private;
-	u16 *iter;
-
-	guard(mutex)(&kvm->arch.config_lock);
 
 	if (!kvm->arch.sysreg_masks)
 		return NULL;
 
-	iter = &kvm->arch.sr_resx_iter;
-	if (*iter != (u16)~0)
-		return ERR_PTR(-EBUSY);
-
-	*iter = *pos;
-	if (!sr_resx_find(kvm, *iter))
-		iter = NULL;
-
-	return iter;
+	return (void *)sr_resx_find(kvm, *pos);
 }
 
 static void *sr_resx_next(struct seq_file *s, void *v, loff_t *pos)
@@ -5136,36 +5123,20 @@ static void *sr_resx_next(struct seq_file *s, void *v, loff_t *pos)
 
 	(*pos)++;
 
-	if (sr_resx_find(kvm, kvm->arch.sr_resx_iter + 1)) {
-		kvm->arch.sr_resx_iter++;
-
-		return &kvm->arch.sr_resx_iter;
-	}
-
-	return NULL;
+	return (void *)sr_resx_find(kvm, *pos);
 }
 
 static void sr_resx_stop(struct seq_file *s, void *v)
 {
-	struct kvm *kvm = s->private;
-
-	if (IS_ERR(v))
-		return;
-
-	guard(mutex)(&kvm->arch.config_lock);
-
-	kvm->arch.sr_resx_iter = ~0;
 }
 
 static int sr_resx_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;
 	struct resx resx;
 
-	desc = sr_resx_find(kvm, kvm->arch.sr_resx_iter);
-
-	if (!desc->name)
+	if (!desc)
 		return 0;
 
 	resx = kvm_get_sysreg_resx(kvm, desc->reg);
@@ -5188,7 +5159,6 @@ DEFINE_SEQ_ATTRIBUTE(sr_resx);
 void kvm_sys_regs_create_debugfs(struct kvm *kvm)
 {
 	kvm->arch.idreg_debugfs_iter = ~0;
-	kvm->arch.sr_resx_iter = ~0;
 
 	debugfs_create_file("idregs", 0444, kvm->debugfs_dentry, kvm,
 			    &idregs_debug_fops);
-- 
2.53.0.rc1.225.gd81095ad13-goog