Documentation/virt/kvm/devices/s390_flic.rst | 11 +++- arch/s390/include/asm/kvm_host.h | 5 ++ arch/s390/kvm/interrupt.c | 59 +++++++++++++++----- 3 files changed, 58 insertions(+), 17 deletions(-)
FOLL_LONGTERM pinning fails for some memory types, such as file-backed
guest memory. As a result, kvm_s390_adapter_map() returns -EINVAL and
irqfd adapter registration fails even though interrupt delivery could
still work via the existing non-atomic path.
When FOLL_LONGTERM pinning fails, verify that the page is accessible
using a short-term pin instead. If the short-term pin succeeds, unpin
the page and add a map entry with pinned=false to preserve MAP/UNMAP
symmetry. The non-atomic irqfd path already performs short-term pinning
for interrupt delivery, so this restores the previous behavior for
memory that cannot be pinned long-term.
get_map_info() is updated to return NULL for unpinned entries so that
the atomic irqfd fast path falls back to the non-atomic path.
kvm_s390_adapter_unmap() and kvm_s390_unmap_all_adapters() skip dirty
marking and unpin for unpinned entries.
Update Documentation/virt/kvm/devices/s390_flic.rst to reflect the
new MAP/UNMAP behavior.
Fixes: adcd5b3e758b ("KVM: s390: Add map/unmap ioctl and clean mappings post-guest")
Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com>
Reviewed-by: Douglas Freimuth <freimuth@linux.ibm.com>
---
Documentation/virt/kvm/devices/s390_flic.rst | 11 +++-
arch/s390/include/asm/kvm_host.h | 5 ++
arch/s390/kvm/interrupt.c | 59 +++++++++++++++-----
3 files changed, 58 insertions(+), 17 deletions(-)
diff --git a/Documentation/virt/kvm/devices/s390_flic.rst b/Documentation/virt/kvm/devices/s390_flic.rst
index b784f8016748..ec9aaae04e22 100644
--- a/Documentation/virt/kvm/devices/s390_flic.rst
+++ b/Documentation/virt/kvm/devices/s390_flic.rst
@@ -112,9 +112,16 @@ Groups:
mask or unmask the adapter, as specified in mask
KVM_S390_IO_ADAPTER_MAP
- This is now a no-op. The mapping is purely done by the irq route.
+ Map an adapter indicator or summary page for long-term pinning so that
+ interrupt injection can be performed in atomic context. If long-term
+ pinning is not possible (e.g. file-backed memory), the page is verified
+ via a short-term pin and the ioctl returns success; interrupt injection
+ will use the non-atomic irqfd path with short-term pinning on each
+ interrupt. In Secure Execution mode this is a no-op.
KVM_S390_IO_ADAPTER_UNMAP
- This is now a no-op. The mapping is purely done by the irq route.
+ Unmap a previously mapped adapter indicator or summary page and release
+ the long-term pin. If the page was not long-term pinned (e.g. file-backed
+ memory or Secure Execution mode), this is a no-op and returns success.
KVM_DEV_FLIC_AISM
modify the adapter-interruption-suppression mode for a given isc if the
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index eaa34c5bd3c1..c172f9b212d1 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -476,6 +476,11 @@ struct s390_map_info {
__u64 guest_addr;
__u64 addr;
struct page *page;
+ /*
+ * True if the page is long-term pinned. False if long-term pinning
+ * failed and this entry exists only to preserve MAP/UNMAP symmetry.
+ */
+ bool pinned;
};
struct s390_io_adapter {
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 9e3e6b0d72ad..75eacd1578ef 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -2520,8 +2520,22 @@ static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)
map->addr = host_addr;
map->page = pin_map_page(kvm, host_addr, FOLL_LONGTERM);
if (!map->page) {
- ret = -EINVAL;
- goto out;
+ /*
+ * Long-term pinning may fail for memory types such as file-backed
+ * memory. Verify that short-term pinning succeeds so that the
+ * non-atomic irqfd path can handle interrupt injection.
+ */
+ map->page = pin_map_page(kvm, host_addr, 0);
+ if (!map->page) {
+ ret = -EINVAL;
+ goto out;
+ }
+ unpin_user_page(map->page);
+ map->page = NULL;
+ map->pinned = false;
+ /* Add an entry to preserve MAP/UNMAP symmetry. */
+ } else {
+ map->pinned = true;
}
spin_lock_irqsave(&adapter->maps_lock, flags);
if (adapter->nr_maps < MAX_S390_ADAPTER_MAPS) {
@@ -2532,7 +2546,7 @@ static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)
ret = -EINVAL;
}
spin_unlock_irqrestore(&adapter->maps_lock, flags);
- if (ret)
+ if (ret && map->page)
unpin_user_page(map->page);
out:
if (ret)
@@ -2546,6 +2560,7 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
struct s390_map_info *map, *tmp, *map_to_free;
struct page *map_page_to_put = NULL;
u64 map_addr_to_mark = 0;
+ bool map_pinned = false;
unsigned long flags;
int found = 0, idx;
@@ -2560,6 +2575,7 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
list_del(&map->list);
map_page_to_put = map->page;
map_addr_to_mark = map->guest_addr;
+ map_pinned = map->pinned;
map_to_free = map;
break;
}
@@ -2568,11 +2584,18 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
if (found) {
kfree(map_to_free);
- idx = srcu_read_lock(&kvm->srcu);
- mark_page_dirty(kvm, map_addr_to_mark >> PAGE_SHIFT);
- set_page_dirty_lock(map_page_to_put);
- srcu_read_unlock(&kvm->srcu, idx);
- unpin_user_page(map_page_to_put);
+ if (map_pinned) {
+ /*
+ * Only long-term pinned pages need to be marked dirty
+ * and released. Fallback entries exist only for
+ * MAP/UNMAP symmetry.
+ */
+ idx = srcu_read_lock(&kvm->srcu);
+ mark_page_dirty(kvm, map_addr_to_mark >> PAGE_SHIFT);
+ set_page_dirty_lock(map_page_to_put);
+ srcu_read_unlock(&kvm->srcu, idx);
+ unpin_user_page(map_page_to_put);
+ }
}
return found ? 0 : -ENOENT;
@@ -2598,11 +2621,13 @@ void kvm_s390_unmap_all_adapters(struct kvm *kvm)
list_for_each_entry_safe(map, tmp, &local_list, list) {
list_del(&map->list);
- idx = srcu_read_lock(&kvm->srcu);
- mark_page_dirty(kvm, map->guest_addr >> PAGE_SHIFT);
- set_page_dirty_lock(map->page);
- srcu_read_unlock(&kvm->srcu, idx);
- unpin_user_page(map->page);
+ if (map->pinned) {
+ idx = srcu_read_lock(&kvm->srcu);
+ mark_page_dirty(kvm, map->guest_addr >> PAGE_SHIFT);
+ set_page_dirty_lock(map->page);
+ srcu_read_unlock(&kvm->srcu, idx);
+ unpin_user_page(map->page);
+ }
kfree(map);
}
}
@@ -2929,8 +2954,12 @@ static struct s390_map_info *get_map_info(struct s390_io_adapter *adapter,
return NULL;
list_for_each_entry(map, &adapter->maps, list) {
- if (map->addr == addr)
- return map;
+ if (map->addr == addr) {
+ if (map->pinned)
+ return map;
+ else
+ return NULL;
+ }
}
return NULL;
}
--
2.54.0On 7/23/26 2:10 PM, Jaehoon Kim wrote:
> FOLL_LONGTERM pinning fails for some memory types, such as file-backed
> guest memory. As a result, kvm_s390_adapter_map() returns -EINVAL and
> irqfd adapter registration fails even though interrupt delivery could
> still work via the existing non-atomic path.
>
> When FOLL_LONGTERM pinning fails, verify that the page is accessible
> using a short-term pin instead. If the short-term pin succeeds, unpin
> the page and add a map entry with pinned=false to preserve MAP/UNMAP
> symmetry. The non-atomic irqfd path already performs short-term pinning
> for interrupt delivery, so this restores the previous behavior for
> memory that cannot be pinned long-term.
>
> get_map_info() is updated to return NULL for unpinned entries so that
> the atomic irqfd fast path falls back to the non-atomic path.
> kvm_s390_adapter_unmap() and kvm_s390_unmap_all_adapters() skip dirty
> marking and unpin for unpinned entries.
>
> Update Documentation/virt/kvm/devices/s390_flic.rst to reflect the
> new MAP/UNMAP behavior.
>
> Fixes: adcd5b3e758b ("KVM: s390: Add map/unmap ioctl and clean mappings post-guest")
cc stable?
> Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com>
> Reviewed-by: Douglas Freimuth <freimuth@linux.ibm.com>
> ---
> Documentation/virt/kvm/devices/s390_flic.rst | 11 +++-
> arch/s390/include/asm/kvm_host.h | 5 ++
> arch/s390/kvm/interrupt.c | 59 +++++++++++++++-----
> 3 files changed, 58 insertions(+), 17 deletions(-)
>
> diff --git a/Documentation/virt/kvm/devices/s390_flic.rst b/Documentation/virt/kvm/devices/s390_flic.rst
> index b784f8016748..ec9aaae04e22 100644
> --- a/Documentation/virt/kvm/devices/s390_flic.rst
> +++ b/Documentation/virt/kvm/devices/s390_flic.rst
> @@ -112,9 +112,16 @@ Groups:
> mask or unmask the adapter, as specified in mask
>
> KVM_S390_IO_ADAPTER_MAP
> - This is now a no-op. The mapping is purely done by the irq route.
> + Map an adapter indicator or summary page for long-term pinning so that
> + interrupt injection can be performed in atomic context. If long-term
> + pinning is not possible (e.g. file-backed memory), the page is verified
> + via a short-term pin and the ioctl returns success; interrupt injection
> + will use the non-atomic irqfd path with short-term pinning on each
> + interrupt. In Secure Execution mode this is a no-op.
Nit:
... this is a no-op and the ioctl returns success.
> KVM_S390_IO_ADAPTER_UNMAP
> - This is now a no-op. The mapping is purely done by the irq route.
> + Unmap a previously mapped adapter indicator or summary page and release
> + the long-term pin. If the page was not long-term pinned (e.g. file-backed
> + memory or Secure Execution mode), this is a no-op and returns success.
Technically not a no-op in the file-backed case, you will still remove a
list entry.
How about a little re-wording:
KVM_S390_IO_ADAPTER_UNMAP
Unmap a previously mapped adapter indicator or summary page and release
the long-term pin. If the page was not long-term pinned (e.g. file-backed
memory), the map entry is removed and success is returned; if no prior
map entry exists, -ENOENT is returned. In Secure Execution mode this is
a no-op and the ioctl returns success.
Otherwise, code looks good to me. Thanks Jaehoon!
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
>
> KVM_DEV_FLIC_AISM
> modify the adapter-interruption-suppression mode for a given isc if the
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index eaa34c5bd3c1..c172f9b212d1 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -476,6 +476,11 @@ struct s390_map_info {
> __u64 guest_addr;
> __u64 addr;
> struct page *page;
> + /*
> + * True if the page is long-term pinned. False if long-term pinning
> + * failed and this entry exists only to preserve MAP/UNMAP symmetry.
> + */
> + bool pinned;
> };
>
> struct s390_io_adapter {
> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
> index 9e3e6b0d72ad..75eacd1578ef 100644
> --- a/arch/s390/kvm/interrupt.c
> +++ b/arch/s390/kvm/interrupt.c
> @@ -2520,8 +2520,22 @@ static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)
> map->addr = host_addr;
> map->page = pin_map_page(kvm, host_addr, FOLL_LONGTERM);
> if (!map->page) {
> - ret = -EINVAL;
> - goto out;
> + /*
> + * Long-term pinning may fail for memory types such as file-backed
> + * memory. Verify that short-term pinning succeeds so that the
> + * non-atomic irqfd path can handle interrupt injection.
> + */
> + map->page = pin_map_page(kvm, host_addr, 0);
> + if (!map->page) {
> + ret = -EINVAL;
> + goto out;
> + }
> + unpin_user_page(map->page);
> + map->page = NULL;
> + map->pinned = false;
> + /* Add an entry to preserve MAP/UNMAP symmetry. */
> + } else {
> + map->pinned = true;
> }
> spin_lock_irqsave(&adapter->maps_lock, flags);
> if (adapter->nr_maps < MAX_S390_ADAPTER_MAPS) {
> @@ -2532,7 +2546,7 @@ static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)
> ret = -EINVAL;
> }
> spin_unlock_irqrestore(&adapter->maps_lock, flags);
> - if (ret)
> + if (ret && map->page)
> unpin_user_page(map->page);
> out:
> if (ret)
> @@ -2546,6 +2560,7 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
> struct s390_map_info *map, *tmp, *map_to_free;
> struct page *map_page_to_put = NULL;
> u64 map_addr_to_mark = 0;
> + bool map_pinned = false;
> unsigned long flags;
> int found = 0, idx;
>
> @@ -2560,6 +2575,7 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
> list_del(&map->list);
> map_page_to_put = map->page;
> map_addr_to_mark = map->guest_addr;
> + map_pinned = map->pinned;
> map_to_free = map;
> break;
> }
> @@ -2568,11 +2584,18 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
>
> if (found) {
> kfree(map_to_free);
> - idx = srcu_read_lock(&kvm->srcu);
> - mark_page_dirty(kvm, map_addr_to_mark >> PAGE_SHIFT);
> - set_page_dirty_lock(map_page_to_put);
> - srcu_read_unlock(&kvm->srcu, idx);
> - unpin_user_page(map_page_to_put);
> + if (map_pinned) {
> + /*
> + * Only long-term pinned pages need to be marked dirty
> + * and released. Fallback entries exist only for
> + * MAP/UNMAP symmetry.
> + */
> + idx = srcu_read_lock(&kvm->srcu);
> + mark_page_dirty(kvm, map_addr_to_mark >> PAGE_SHIFT);
> + set_page_dirty_lock(map_page_to_put);
> + srcu_read_unlock(&kvm->srcu, idx);
> + unpin_user_page(map_page_to_put);
> + }
> }
>
> return found ? 0 : -ENOENT;
> @@ -2598,11 +2621,13 @@ void kvm_s390_unmap_all_adapters(struct kvm *kvm)
>
> list_for_each_entry_safe(map, tmp, &local_list, list) {
> list_del(&map->list);
> - idx = srcu_read_lock(&kvm->srcu);
> - mark_page_dirty(kvm, map->guest_addr >> PAGE_SHIFT);
> - set_page_dirty_lock(map->page);
> - srcu_read_unlock(&kvm->srcu, idx);
> - unpin_user_page(map->page);
> + if (map->pinned) {
> + idx = srcu_read_lock(&kvm->srcu);
> + mark_page_dirty(kvm, map->guest_addr >> PAGE_SHIFT);
> + set_page_dirty_lock(map->page);
> + srcu_read_unlock(&kvm->srcu, idx);
> + unpin_user_page(map->page);
> + }
> kfree(map);
> }
> }
> @@ -2929,8 +2954,12 @@ static struct s390_map_info *get_map_info(struct s390_io_adapter *adapter,
> return NULL;
>
> list_for_each_entry(map, &adapter->maps, list) {
> - if (map->addr == addr)
> - return map;
> + if (map->addr == addr) {
> + if (map->pinned)
> + return map;
> + else
> + return NULL;
> + }
> }
> return NULL;
> }
On 7/23/2026 2:12 PM, Matthew Rosato wrote:
> On 7/23/26 2:10 PM, Jaehoon Kim wrote:
>> FOLL_LONGTERM pinning fails for some memory types, such as file-backed
>> guest memory. As a result, kvm_s390_adapter_map() returns -EINVAL and
>> irqfd adapter registration fails even though interrupt delivery could
>> still work via the existing non-atomic path.
>>
>> When FOLL_LONGTERM pinning fails, verify that the page is accessible
>> using a short-term pin instead. If the short-term pin succeeds, unpin
>> the page and add a map entry with pinned=false to preserve MAP/UNMAP
>> symmetry. The non-atomic irqfd path already performs short-term pinning
>> for interrupt delivery, so this restores the previous behavior for
>> memory that cannot be pinned long-term.
>>
>> get_map_info() is updated to return NULL for unpinned entries so that
>> the atomic irqfd fast path falls back to the non-atomic path.
>> kvm_s390_adapter_unmap() and kvm_s390_unmap_all_adapters() skip dirty
>> marking and unpin for unpinned entries.
>>
>> Update Documentation/virt/kvm/devices/s390_flic.rst to reflect the
>> new MAP/UNMAP behavior.
>>
>> Fixes: adcd5b3e758b ("KVM: s390: Add map/unmap ioctl and clean mappings post-guest")
> cc stable?
Thanks for your feedback.
Since the fixed commit first landed in v7.2-rc1, I don't think this needs to be
CC'd to stable.
The Fixes: tag should reference the mainline commit c9a5688380865b instead of
adcd5b3e758b, which is from the development branch.
I'll update it in the next version.
>
>> Signed-off-by: Jaehoon Kim <jhkim@linux.ibm.com>
>> Reviewed-by: Douglas Freimuth <freimuth@linux.ibm.com>
>> ---
>> Documentation/virt/kvm/devices/s390_flic.rst | 11 +++-
>> arch/s390/include/asm/kvm_host.h | 5 ++
>> arch/s390/kvm/interrupt.c | 59 +++++++++++++++-----
>> 3 files changed, 58 insertions(+), 17 deletions(-)
>>
>> diff --git a/Documentation/virt/kvm/devices/s390_flic.rst b/Documentation/virt/kvm/devices/s390_flic.rst
>> index b784f8016748..ec9aaae04e22 100644
>> --- a/Documentation/virt/kvm/devices/s390_flic.rst
>> +++ b/Documentation/virt/kvm/devices/s390_flic.rst
>> @@ -112,9 +112,16 @@ Groups:
>> mask or unmask the adapter, as specified in mask
>>
>> KVM_S390_IO_ADAPTER_MAP
>> - This is now a no-op. The mapping is purely done by the irq route.
>> + Map an adapter indicator or summary page for long-term pinning so that
>> + interrupt injection can be performed in atomic context. If long-term
>> + pinning is not possible (e.g. file-backed memory), the page is verified
>> + via a short-term pin and the ioctl returns success; interrupt injection
>> + will use the non-atomic irqfd path with short-term pinning on each
>> + interrupt. In Secure Execution mode this is a no-op.
> Nit:
> ... this is a no-op and the ioctl returns success.
I will fix in the next version, thanks.
>
>> KVM_S390_IO_ADAPTER_UNMAP
>> - This is now a no-op. The mapping is purely done by the irq route.
>> + Unmap a previously mapped adapter indicator or summary page and release
>> + the long-term pin. If the page was not long-term pinned (e.g. file-backed
>> + memory or Secure Execution mode), this is a no-op and returns success.
> Technically not a no-op in the file-backed case, you will still remove a
> list entry.
>
> How about a little re-wording:
>
> KVM_S390_IO_ADAPTER_UNMAP
> Unmap a previously mapped adapter indicator or summary page and release
> the long-term pin. If the page was not long-term pinned (e.g. file-backed
> memory), the map entry is removed and success is returned; if no prior
> map entry exists, -ENOENT is returned. In Secure Execution mode this is
> a no-op and the ioctl returns success.
You're right. In the file-backed case, the map entry is still removed, so
describing it as a no-op is inaccurate. I'll update the documentation based
on your suggested in the next version.
Thanks for the review!
>
> Otherwise, code looks good to me. Thanks Jaehoon!
>
> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
>
>>
>> KVM_DEV_FLIC_AISM
>> modify the adapter-interruption-suppression mode for a given isc if the
>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
>> index eaa34c5bd3c1..c172f9b212d1 100644
>> --- a/arch/s390/include/asm/kvm_host.h
>> +++ b/arch/s390/include/asm/kvm_host.h
>> @@ -476,6 +476,11 @@ struct s390_map_info {
>> __u64 guest_addr;
>> __u64 addr;
>> struct page *page;
>> + /*
>> + * True if the page is long-term pinned. False if long-term pinning
>> + * failed and this entry exists only to preserve MAP/UNMAP symmetry.
>> + */
>> + bool pinned;
>> };
>>
>> struct s390_io_adapter {
>> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
>> index 9e3e6b0d72ad..75eacd1578ef 100644
>> --- a/arch/s390/kvm/interrupt.c
>> +++ b/arch/s390/kvm/interrupt.c
>> @@ -2520,8 +2520,22 @@ static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)
>> map->addr = host_addr;
>> map->page = pin_map_page(kvm, host_addr, FOLL_LONGTERM);
>> if (!map->page) {
>> - ret = -EINVAL;
>> - goto out;
>> + /*
>> + * Long-term pinning may fail for memory types such as file-backed
>> + * memory. Verify that short-term pinning succeeds so that the
>> + * non-atomic irqfd path can handle interrupt injection.
>> + */
>> + map->page = pin_map_page(kvm, host_addr, 0);
>> + if (!map->page) {
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> + unpin_user_page(map->page);
>> + map->page = NULL;
>> + map->pinned = false;
>> + /* Add an entry to preserve MAP/UNMAP symmetry. */
>> + } else {
>> + map->pinned = true;
>> }
>> spin_lock_irqsave(&adapter->maps_lock, flags);
>> if (adapter->nr_maps < MAX_S390_ADAPTER_MAPS) {
>> @@ -2532,7 +2546,7 @@ static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)
>> ret = -EINVAL;
>> }
>> spin_unlock_irqrestore(&adapter->maps_lock, flags);
>> - if (ret)
>> + if (ret && map->page)
>> unpin_user_page(map->page);
>> out:
>> if (ret)
>> @@ -2546,6 +2560,7 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
>> struct s390_map_info *map, *tmp, *map_to_free;
>> struct page *map_page_to_put = NULL;
>> u64 map_addr_to_mark = 0;
>> + bool map_pinned = false;
>> unsigned long flags;
>> int found = 0, idx;
>>
>> @@ -2560,6 +2575,7 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
>> list_del(&map->list);
>> map_page_to_put = map->page;
>> map_addr_to_mark = map->guest_addr;
>> + map_pinned = map->pinned;
>> map_to_free = map;
>> break;
>> }
>> @@ -2568,11 +2584,18 @@ static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)
>>
>> if (found) {
>> kfree(map_to_free);
>> - idx = srcu_read_lock(&kvm->srcu);
>> - mark_page_dirty(kvm, map_addr_to_mark >> PAGE_SHIFT);
>> - set_page_dirty_lock(map_page_to_put);
>> - srcu_read_unlock(&kvm->srcu, idx);
>> - unpin_user_page(map_page_to_put);
>> + if (map_pinned) {
>> + /*
>> + * Only long-term pinned pages need to be marked dirty
>> + * and released. Fallback entries exist only for
>> + * MAP/UNMAP symmetry.
>> + */
>> + idx = srcu_read_lock(&kvm->srcu);
>> + mark_page_dirty(kvm, map_addr_to_mark >> PAGE_SHIFT);
>> + set_page_dirty_lock(map_page_to_put);
>> + srcu_read_unlock(&kvm->srcu, idx);
>> + unpin_user_page(map_page_to_put);
>> + }
>> }
>>
>> return found ? 0 : -ENOENT;
>> @@ -2598,11 +2621,13 @@ void kvm_s390_unmap_all_adapters(struct kvm *kvm)
>>
>> list_for_each_entry_safe(map, tmp, &local_list, list) {
>> list_del(&map->list);
>> - idx = srcu_read_lock(&kvm->srcu);
>> - mark_page_dirty(kvm, map->guest_addr >> PAGE_SHIFT);
>> - set_page_dirty_lock(map->page);
>> - srcu_read_unlock(&kvm->srcu, idx);
>> - unpin_user_page(map->page);
>> + if (map->pinned) {
>> + idx = srcu_read_lock(&kvm->srcu);
>> + mark_page_dirty(kvm, map->guest_addr >> PAGE_SHIFT);
>> + set_page_dirty_lock(map->page);
>> + srcu_read_unlock(&kvm->srcu, idx);
>> + unpin_user_page(map->page);
>> + }
>> kfree(map);
>> }
>> }
>> @@ -2929,8 +2954,12 @@ static struct s390_map_info *get_map_info(struct s390_io_adapter *adapter,
>> return NULL;
>>
>> list_for_each_entry(map, &adapter->maps, list) {
>> - if (map->addr == addr)
>> - return map;
>> + if (map->addr == addr) {
>> + if (map->pinned)
>> + return map;
>> + else
>> + return NULL;
>> + }
>> }
>> return NULL;
>> }
>>> Fixes: adcd5b3e758b ("KVM: s390: Add map/unmap ioctl and clean
>>> mappings post-guest")
>> cc stable?
>
> Thanks for your feedback.
>
> Since the fixed commit first landed in v7.2-rc1, I don't think this
> needs to be
> CC'd to stable.
Ah right, good point. Forgot it landed in -rc1.
>
> The Fixes: tag should reference the mainline commit c9a5688380865b
> instead of
> adcd5b3e758b, which is from the development branch.
>
> I'll update it in the next version.
Good catch, thanks. I just double-checked and yes c9a568838086 is the
one you want.
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