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KVM: s390: Fix dirty marking in adapter_indicators_set*()

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When the indicator and/or summary bits are set in the guest, the
accessed page was only marked dirty in KVM 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 mark_page_dirty(). Note that
for the inatomic path set_page_dirty{,_lock}() is not needed as the
page stays pinned; the unpin path correctly marks it as dirty.

Opportunistically reorder the local variables to be in reverse
Christmas tree order and refactor to use guard().

Fixes: 1e95e3bc6b ("KVM: s390: Enable adapter_indicators_set to use mapped pages")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-ID: <20260828115439.145885-2-imbrenda@linux.ibm.com>
This commit is contained in:
Claudio Imbrenda 2026-08-28 13:54:32 +02:00
parent 786262be60
commit d215f014b3
1 changed files with 39 additions and 38 deletions
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77
arch/s390/kvm/s390/interrupt.c
View File

@ -2984,61 +2984,58 @@ 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;
ind_page = NULL;
spin_lock_irqsave(&adapter->maps_lock, flags);
ind_info = get_map_info(adapter, adapter_int->ind_addr);
scoped_guard(spinlock_irqsave, &adapter->maps_lock) {
ind_info = get_map_info(adapter, adapter_int->ind_addr);
if (ind_info) {
map = page_address(ind_info->page);
bit = get_ind_bit(ind_info->addr, adapter_int->ind_offset, adapter->swap);
set_bit(bit, map);
}
}
if (!ind_info) {
spin_unlock_irqrestore(&adapter->maps_lock, flags);
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);
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);
spin_unlock_irqrestore(&adapter->maps_lock, flags);
}
scoped_guard(srcu, &kvm->srcu)
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);
scoped_guard(spinlock_irqsave, &adapter->maps_lock) {
summary_info = get_map_info(adapter, adapter_int->summary_addr);
if (summary_info) {
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);
}
}
if (!summary_info) {
spin_unlock_irqrestore(&adapter->maps_lock, flags);
summary_page = pin_map_page(kvm, adapter_int->summary_addr, 0);
if (!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);
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);
spin_unlock_irqrestore(&adapter->maps_lock, flags);
}
scoped_guard(srcu, &kvm->srcu)
mark_page_dirty(kvm, gpa_to_gfn(adapter_int->summary_gaddr));
return summary_set ? 0 : 1;
}
@ -3048,26 +3045,29 @@ 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) {
set_bit(bit, map);
summary_info = get_map_info(adapter, adapter_int->summary_addr);
if (!summary_info) {
spin_unlock(&adapter->maps_lock);
return -EWOULDBLOCK;
mark_page_dirty(kvm, gpa_to_gfn(adapter_int->ind_gaddr));
}
summary_info = get_map_info(adapter, adapter_int->summary_addr);
if (!summary_info)
return -EWOULDBLOCK;
map = page_address(summary_info->page);
bit = get_ind_bit(summary_info->addr, adapter_int->summary_offset,
adapter->swap);
@ -3077,7 +3077,8 @@ 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));
return summary_set ? 0 : 1;
}