[PATCH v2 4/9] KVM: s390: Fix dirty marking in adapter_indicators_set*()

[Claudio Imbrenda]

When the indicator and/or summary bits are set in the guest, the
accessed page was only marked dirty if the access was performed using
the slow path; accesses through the new kvm_arch_set_irq_inatomic fast
inject path would not mark the page as dirty.

Fix by adding/moving the missing calls to set_page_dirty() and
mark_page_dirty().

Opportunistically reorder the local variables to be in reverse
Christmas tree order.

Fixes: 1e95e3bc6b05 ("KVM: s390: Enable adapter_indicators_set to use mapped pages")
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
 arch/s390/kvm/interrupt.c | 48 ++++++++++++++++++++++-----------------
 1 file changed, 27 insertions(+), 21 deletions(-)

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 61e75d10110e..8e4b88bce31f 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -2953,12 +2953,14 @@ static int adapter_indicators_set(struct kvm *kvm,
 				  struct s390_io_adapter *adapter,
 				  struct kvm_s390_adapter_int *adapter_int)
 {
-	unsigned long bit;
-	int summary_set, idx;
 	struct s390_map_info *ind_info, *summary_info;
-	void *map;
 	struct page *ind_page, *summary_page;
 	unsigned long flags;
+	unsigned long bit;
+	int summary_set;
+	void *map;
+
+	guard(srcu)(&kvm->srcu);
 
 	ind_page = NULL;
 
@@ -2969,21 +2971,20 @@ static int adapter_indicators_set(struct kvm *kvm,
 		ind_page = pin_map_page(kvm, adapter_int->ind_addr, 0);
 		if (!ind_page)
 			return -1;
-		idx = srcu_read_lock(&kvm->srcu);
 		map = page_address(ind_page);
 		bit = get_ind_bit(adapter_int->ind_addr,
 				  adapter_int->ind_offset, adapter->swap);
 		set_bit(bit, map);
-		mark_page_dirty(kvm, adapter_int->ind_gaddr >> PAGE_SHIFT);
-		set_page_dirty_lock(ind_page);
-		srcu_read_unlock(&kvm->srcu, idx);
+		set_page_dirty(ind_page);
 		unpin_user_page(ind_page);
 	} else {
 		map = page_address(ind_info->page);
 		bit = get_ind_bit(ind_info->addr, adapter_int->ind_offset, adapter->swap);
 		set_bit(bit, map);
+		set_page_dirty(ind_info->page);
 		spin_unlock_irqrestore(&adapter->maps_lock, flags);
 	}
+	mark_page_dirty(kvm, gpa_to_gfn(adapter_int->ind_gaddr));
 
 	spin_lock_irqsave(&adapter->maps_lock, flags);
 	summary_info = get_map_info(adapter, adapter_int->summary_addr);
@@ -2992,22 +2993,21 @@ static int adapter_indicators_set(struct kvm *kvm,
 		summary_page = pin_map_page(kvm, adapter_int->summary_addr, 0);
 		if (WARN_ON_ONCE(!summary_page))
 			return -1;
-		idx = srcu_read_lock(&kvm->srcu);
 		map = page_address(summary_page);
 		bit = get_ind_bit(adapter_int->summary_addr,
 				  adapter_int->summary_offset, adapter->swap);
 		summary_set = test_and_set_bit(bit, map);
-		mark_page_dirty(kvm, adapter_int->summary_gaddr >> PAGE_SHIFT);
-		set_page_dirty_lock(summary_page);
-		srcu_read_unlock(&kvm->srcu, idx);
+		set_page_dirty(summary_page);
 		unpin_user_page(summary_page);
 	} else {
 		map = page_address(summary_info->page);
 		bit = get_ind_bit(summary_info->addr, adapter_int->summary_offset,
 				  adapter->swap);
 		summary_set = test_and_set_bit(bit, map);
+		set_page_dirty(summary_info->page);
 		spin_unlock_irqrestore(&adapter->maps_lock, flags);
 	}
+	mark_page_dirty(kvm, gpa_to_gfn(adapter_int->summary_gaddr));
 
 	return summary_set ? 0 : 1;
 }
@@ -3017,26 +3017,30 @@ static int adapter_indicators_set_fast(struct kvm *kvm,
 				       struct kvm_s390_adapter_int *adapter_int,
 				       int setbit)
 {
+	struct s390_map_info *ind_info, *summary_info;
 	unsigned long bit;
 	int summary_set;
-	struct s390_map_info *ind_info, *summary_info;
 	void *map;
 
-	spin_lock(&adapter->maps_lock);
+	guard(srcu)(&kvm->srcu);
+	guard(spinlock)(&adapter->maps_lock);
+
 	ind_info = get_map_info(adapter, adapter_int->ind_addr);
-	if (!ind_info) {
-		spin_unlock(&adapter->maps_lock);
+	if (!ind_info)
 		return -EWOULDBLOCK;
-	}
+
 	map = page_address(ind_info->page);
 	bit = get_ind_bit(ind_info->addr, adapter_int->ind_offset, adapter->swap);
-	if (setbit)
+	if (setbit) {
+		mark_page_dirty(kvm, gpa_to_gfn(adapter_int->ind_gaddr));
+		set_page_dirty(ind_info->page);
 		set_bit(bit, map);
+	}
+
 	summary_info = get_map_info(adapter, adapter_int->summary_addr);
-	if (!summary_info) {
-		spin_unlock(&adapter->maps_lock);
+	if (!summary_info)
 		return -EWOULDBLOCK;
-	}
+
 	map = page_address(summary_info->page);
 	bit = get_ind_bit(summary_info->addr, adapter_int->summary_offset,
 			  adapter->swap);
@@ -3046,7 +3050,9 @@ static int adapter_indicators_set_fast(struct kvm *kvm,
 		summary_set = test_and_set_bit(bit, map);
 	else
 		summary_set = test_and_clear_bit(bit, map);
-	spin_unlock(&adapter->maps_lock);
+	mark_page_dirty(kvm, gpa_to_gfn(adapter_int->summary_gaddr));
+	set_page_dirty(summary_info->page);
+
 	return summary_set ? 0 : 1;
 }
 
-- 
2.55.0