* [PATCH v2 01/10] s390/uv: don't call folio_wait_writeback() without a folio reference
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-04-12 14:21 ` [PATCH v2 02/10] s390/uv: gmap_make_secure() cleanups for further changes David Hildenbrand
` (9 subsequent siblings)
10 siblings, 0 replies; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
folio_wait_writeback() requires that no spinlocks are held and that
a folio reference is held, as documented. After we dropped the PTL, the
folio could get freed concurrently. So grab a temporary reference.
Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests")
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/kernel/uv.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 265fea37e030..016993e9eb72 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -318,6 +318,13 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
rc = make_folio_secure(folio, uvcb);
folio_unlock(folio);
}
+
+ /*
+ * Once we drop the PTL, the folio may get unmapped and
+ * freed immediately. We need a temporary reference.
+ */
+ if (rc == -EAGAIN)
+ folio_get(folio);
}
unlock:
pte_unmap_unlock(ptep, ptelock);
@@ -330,6 +337,7 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
* completion, this is just a useless check, but it is safe.
*/
folio_wait_writeback(folio);
+ folio_put(folio);
} else if (rc == -EBUSY) {
/*
* If we have tried a local drain and the folio refcount
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* [PATCH v2 02/10] s390/uv: gmap_make_secure() cleanups for further changes
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
2024-04-12 14:21 ` [PATCH v2 01/10] s390/uv: don't call folio_wait_writeback() without a folio reference David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-05-07 15:27 ` Claudio Imbrenda
2024-04-12 14:21 ` [PATCH v2 03/10] s390/uv: split large folios in gmap_make_secure() David Hildenbrand
` (8 subsequent siblings)
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
Let's factor out handling of LRU cache draining and convert the if-else
chain to a switch-case.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/kernel/uv.c | 66 ++++++++++++++++++++++++++-----------------
1 file changed, 40 insertions(+), 26 deletions(-)
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 016993e9eb72..25fe28d189df 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -266,6 +266,36 @@ static bool should_export_before_import(struct uv_cb_header *uvcb, struct mm_str
return atomic_read(&mm->context.protected_count) > 1;
}
+/*
+ * Drain LRU caches: the local one on first invocation and the ones of all
+ * CPUs on successive invocations. Returns "true" on the first invocation.
+ */
+static bool drain_lru(bool *drain_lru_called)
+{
+ /*
+ * If we have tried a local drain and the folio refcount
+ * still does not match our expected safe value, try with a
+ * system wide drain. This is needed if the pagevecs holding
+ * the page are on a different CPU.
+ */
+ if (*drain_lru_called) {
+ lru_add_drain_all();
+ /* We give up here, don't retry immediately. */
+ return false;
+ }
+ /*
+ * We are here if the folio refcount does not match the
+ * expected safe value. The main culprits are usually
+ * pagevecs. With lru_add_drain() we drain the pagevecs
+ * on the local CPU so that hopefully the refcount will
+ * reach the expected safe value.
+ */
+ lru_add_drain();
+ *drain_lru_called = true;
+ /* The caller should try again immediately */
+ return true;
+}
+
/*
* Requests the Ultravisor to make a page accessible to a guest.
* If it's brought in the first time, it will be cleared. If
@@ -275,7 +305,7 @@ static bool should_export_before_import(struct uv_cb_header *uvcb, struct mm_str
int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
{
struct vm_area_struct *vma;
- bool local_drain = false;
+ bool drain_lru_called = false;
spinlock_t *ptelock;
unsigned long uaddr;
struct folio *folio;
@@ -331,37 +361,21 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
out:
mmap_read_unlock(gmap->mm);
- if (rc == -EAGAIN) {
+ switch (rc) {
+ case -EAGAIN:
/*
* If we are here because the UVC returned busy or partial
* completion, this is just a useless check, but it is safe.
*/
folio_wait_writeback(folio);
folio_put(folio);
- } else if (rc == -EBUSY) {
- /*
- * If we have tried a local drain and the folio refcount
- * still does not match our expected safe value, try with a
- * system wide drain. This is needed if the pagevecs holding
- * the page are on a different CPU.
- */
- if (local_drain) {
- lru_add_drain_all();
- /* We give up here, and let the caller try again */
- return -EAGAIN;
- }
- /*
- * We are here if the folio refcount does not match the
- * expected safe value. The main culprits are usually
- * pagevecs. With lru_add_drain() we drain the pagevecs
- * on the local CPU so that hopefully the refcount will
- * reach the expected safe value.
- */
- lru_add_drain();
- local_drain = true;
- /* And now we try again immediately after draining */
- goto again;
- } else if (rc == -ENXIO) {
+ return -EAGAIN;
+ case -EBUSY:
+ /* Additional folio references. */
+ if (drain_lru(&drain_lru_called))
+ goto again;
+ return -EAGAIN;
+ case -ENXIO:
if (gmap_fault(gmap, gaddr, FAULT_FLAG_WRITE))
return -EFAULT;
return -EAGAIN;
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* Re: [PATCH v2 02/10] s390/uv: gmap_make_secure() cleanups for further changes
2024-04-12 14:21 ` [PATCH v2 02/10] s390/uv: gmap_make_secure() cleanups for further changes David Hildenbrand
@ 2024-05-07 15:27 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 15:27 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Fri, 12 Apr 2024 16:21:12 +0200
David Hildenbrand <david@redhat.com> wrote:
> Let's factor out handling of LRU cache draining and convert the if-else
> chain to a switch-case.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
it is a little ugly with the bool* parameter, but I can't think of
a better/nicer way to do it
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> arch/s390/kernel/uv.c | 66 ++++++++++++++++++++++++++-----------------
> 1 file changed, 40 insertions(+), 26 deletions(-)
>
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index 016993e9eb72..25fe28d189df 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -266,6 +266,36 @@ static bool should_export_before_import(struct uv_cb_header *uvcb, struct mm_str
> return atomic_read(&mm->context.protected_count) > 1;
> }
>
> +/*
> + * Drain LRU caches: the local one on first invocation and the ones of all
> + * CPUs on successive invocations. Returns "true" on the first invocation.
> + */
> +static bool drain_lru(bool *drain_lru_called)
> +{
> + /*
> + * If we have tried a local drain and the folio refcount
> + * still does not match our expected safe value, try with a
> + * system wide drain. This is needed if the pagevecs holding
> + * the page are on a different CPU.
> + */
> + if (*drain_lru_called) {
> + lru_add_drain_all();
> + /* We give up here, don't retry immediately. */
> + return false;
> + }
> + /*
> + * We are here if the folio refcount does not match the
> + * expected safe value. The main culprits are usually
> + * pagevecs. With lru_add_drain() we drain the pagevecs
> + * on the local CPU so that hopefully the refcount will
> + * reach the expected safe value.
> + */
> + lru_add_drain();
> + *drain_lru_called = true;
> + /* The caller should try again immediately */
> + return true;
> +}
> +
> /*
> * Requests the Ultravisor to make a page accessible to a guest.
> * If it's brought in the first time, it will be cleared. If
> @@ -275,7 +305,7 @@ static bool should_export_before_import(struct uv_cb_header *uvcb, struct mm_str
> int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
> {
> struct vm_area_struct *vma;
> - bool local_drain = false;
> + bool drain_lru_called = false;
> spinlock_t *ptelock;
> unsigned long uaddr;
> struct folio *folio;
> @@ -331,37 +361,21 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
> out:
> mmap_read_unlock(gmap->mm);
>
> - if (rc == -EAGAIN) {
> + switch (rc) {
> + case -EAGAIN:
> /*
> * If we are here because the UVC returned busy or partial
> * completion, this is just a useless check, but it is safe.
> */
> folio_wait_writeback(folio);
> folio_put(folio);
> - } else if (rc == -EBUSY) {
> - /*
> - * If we have tried a local drain and the folio refcount
> - * still does not match our expected safe value, try with a
> - * system wide drain. This is needed if the pagevecs holding
> - * the page are on a different CPU.
> - */
> - if (local_drain) {
> - lru_add_drain_all();
> - /* We give up here, and let the caller try again */
> - return -EAGAIN;
> - }
> - /*
> - * We are here if the folio refcount does not match the
> - * expected safe value. The main culprits are usually
> - * pagevecs. With lru_add_drain() we drain the pagevecs
> - * on the local CPU so that hopefully the refcount will
> - * reach the expected safe value.
> - */
> - lru_add_drain();
> - local_drain = true;
> - /* And now we try again immediately after draining */
> - goto again;
> - } else if (rc == -ENXIO) {
> + return -EAGAIN;
> + case -EBUSY:
> + /* Additional folio references. */
> + if (drain_lru(&drain_lru_called))
> + goto again;
> + return -EAGAIN;
> + case -ENXIO:
> if (gmap_fault(gmap, gaddr, FAULT_FLAG_WRITE))
> return -EFAULT;
> return -EAGAIN;
^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 03/10] s390/uv: split large folios in gmap_make_secure()
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
2024-04-12 14:21 ` [PATCH v2 01/10] s390/uv: don't call folio_wait_writeback() without a folio reference David Hildenbrand
2024-04-12 14:21 ` [PATCH v2 02/10] s390/uv: gmap_make_secure() cleanups for further changes David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-05-07 15:43 ` Claudio Imbrenda
2024-04-12 14:21 ` [PATCH v2 04/10] s390/uv: convert PG_arch_1 users to only work on small folios David Hildenbrand
` (7 subsequent siblings)
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
While s390x makes sure to never have PMD-mapped THP in processes that use
KVM -- by remapping them using PTEs in
thp_split_walk_pmd_entry()->split_huge_pmd() -- there is still the
possibility of having PTE-mapped THPs (large folios) mapped into guest
memory.
This would happen if user space allocates memory before calling
KVM_CREATE_VM (which would call s390_enable_sie()). With upstream QEMU,
this currently doesn't happen, because guest memory is setup and
condiitonally preallocated after KVM_CREATE_VM.
Could it happen with shmem/file-backed memory when another process
allocated memory in the pagecache? Likely, although currently not a
common setup.
Trying to split any PTE-mapped large folios sounds like the right and
future-proof thing to do here. So let's call split_folio() and handle the
return values accordingly.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/kernel/uv.c | 31 +++++++++++++++++++++++++------
1 file changed, 25 insertions(+), 6 deletions(-)
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 25fe28d189df..3c6d86e3e828 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -338,11 +338,10 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
goto out;
if (pte_present(*ptep) && !(pte_val(*ptep) & _PAGE_INVALID) && pte_write(*ptep)) {
folio = page_folio(pte_page(*ptep));
- rc = -EINVAL;
- if (folio_test_large(folio))
- goto unlock;
rc = -EAGAIN;
- if (folio_trylock(folio)) {
+ if (folio_test_large(folio)) {
+ rc = -E2BIG;
+ } else if (folio_trylock(folio)) {
if (should_export_before_import(uvcb, gmap->mm))
uv_convert_from_secure(PFN_PHYS(folio_pfn(folio)));
rc = make_folio_secure(folio, uvcb);
@@ -353,15 +352,35 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
* Once we drop the PTL, the folio may get unmapped and
* freed immediately. We need a temporary reference.
*/
- if (rc == -EAGAIN)
+ if (rc == -EAGAIN || rc == -E2BIG)
folio_get(folio);
}
-unlock:
pte_unmap_unlock(ptep, ptelock);
out:
mmap_read_unlock(gmap->mm);
switch (rc) {
+ case -E2BIG:
+ folio_lock(folio);
+ rc = split_folio(folio);
+ folio_unlock(folio);
+ folio_put(folio);
+
+ switch (rc) {
+ case 0:
+ /* Splitting succeeded, try again immediately. */
+ goto again;
+ case -EAGAIN:
+ /* Additional folio references. */
+ if (drain_lru(&drain_lru_called))
+ goto again;
+ return -EAGAIN;
+ case -EBUSY:
+ /* Unexpected race. */
+ return -EAGAIN;
+ }
+ WARN_ON_ONCE(1);
+ return -ENXIO;
case -EAGAIN:
/*
* If we are here because the UVC returned busy or partial
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* Re: [PATCH v2 03/10] s390/uv: split large folios in gmap_make_secure()
2024-04-12 14:21 ` [PATCH v2 03/10] s390/uv: split large folios in gmap_make_secure() David Hildenbrand
@ 2024-05-07 15:43 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 15:43 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Fri, 12 Apr 2024 16:21:13 +0200
David Hildenbrand <david@redhat.com> wrote:
> While s390x makes sure to never have PMD-mapped THP in processes that use
> KVM -- by remapping them using PTEs in
> thp_split_walk_pmd_entry()->split_huge_pmd() -- there is still the
> possibility of having PTE-mapped THPs (large folios) mapped into guest
> memory.
>
> This would happen if user space allocates memory before calling
> KVM_CREATE_VM (which would call s390_enable_sie()). With upstream QEMU,
> this currently doesn't happen, because guest memory is setup and
> condiitonally preallocated after KVM_CREATE_VM.
*conditionally
>
> Could it happen with shmem/file-backed memory when another process
> allocated memory in the pagecache? Likely, although currently not a
> common setup.
>
> Trying to split any PTE-mapped large folios sounds like the right and
> future-proof thing to do here. So let's call split_folio() and handle the
> return values accordingly.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
> arch/s390/kernel/uv.c | 31 +++++++++++++++++++++++++------
> 1 file changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index 25fe28d189df..3c6d86e3e828 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -338,11 +338,10 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
> goto out;
> if (pte_present(*ptep) && !(pte_val(*ptep) & _PAGE_INVALID) && pte_write(*ptep)) {
> folio = page_folio(pte_page(*ptep));
> - rc = -EINVAL;
> - if (folio_test_large(folio))
> - goto unlock;
> rc = -EAGAIN;
> - if (folio_trylock(folio)) {
> + if (folio_test_large(folio)) {
> + rc = -E2BIG;
> + } else if (folio_trylock(folio)) {
> if (should_export_before_import(uvcb, gmap->mm))
> uv_convert_from_secure(PFN_PHYS(folio_pfn(folio)));
> rc = make_folio_secure(folio, uvcb);
> @@ -353,15 +352,35 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb)
> * Once we drop the PTL, the folio may get unmapped and
> * freed immediately. We need a temporary reference.
> */
> - if (rc == -EAGAIN)
> + if (rc == -EAGAIN || rc == -E2BIG)
> folio_get(folio);
> }
> -unlock:
> pte_unmap_unlock(ptep, ptelock);
> out:
> mmap_read_unlock(gmap->mm);
>
> switch (rc) {
> + case -E2BIG:
> + folio_lock(folio);
> + rc = split_folio(folio);
> + folio_unlock(folio);
> + folio_put(folio);
> +
> + switch (rc) {
> + case 0:
> + /* Splitting succeeded, try again immediately. */
> + goto again;
> + case -EAGAIN:
> + /* Additional folio references. */
> + if (drain_lru(&drain_lru_called))
> + goto again;
> + return -EAGAIN;
> + case -EBUSY:
> + /* Unexpected race. */
> + return -EAGAIN;
> + }
> + WARN_ON_ONCE(1);
> + return -ENXIO;
> case -EAGAIN:
> /*
> * If we are here because the UVC returned busy or partial
^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 04/10] s390/uv: convert PG_arch_1 users to only work on small folios
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
` (2 preceding siblings ...)
2024-04-12 14:21 ` [PATCH v2 03/10] s390/uv: split large folios in gmap_make_secure() David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-05-07 15:49 ` Claudio Imbrenda
2024-04-12 14:21 ` [PATCH v2 05/10] s390/uv: update PG_arch_1 comment David Hildenbrand
` (6 subsequent siblings)
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
Now that make_folio_secure() may only set PG_arch_1 for small folios,
let's convert relevant remaining UV code to only work on (small) folios
and simply reject large folios early. This way, we'll never end up
touching PG_arch_1 on tail pages of a large folio in UV code.
The folio_get()/folio_put() for functions that are documented to already
hold a folio reference look weird; likely they are required to make
concurrent gmap_make_secure() back off because the caller might only hold
an implicit reference due to the page mapping. So leave that alone for now.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/include/asm/page.h | 2 ++
arch/s390/kernel/uv.c | 41 ++++++++++++++++++++++--------------
2 files changed, 27 insertions(+), 16 deletions(-)
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 9381879f7ecf..b64384872c0f 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -214,7 +214,9 @@ static inline unsigned long __phys_addr(unsigned long x, bool is_31bit)
#define pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT)
#define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
+#define phys_to_folio(phys) page_folio(phys_to_page(phys))
#define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
+#define folio_to_phys(page) pfn_to_phys(folio_pfn(folio))
static inline void *pfn_to_virt(unsigned long pfn)
{
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 3c6d86e3e828..914dcec27329 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -135,14 +135,18 @@ static int uv_destroy_page(unsigned long paddr)
*/
int uv_destroy_owned_page(unsigned long paddr)
{
- struct page *page = phys_to_page(paddr);
+ struct folio *folio = phys_to_folio(paddr);
int rc;
- get_page(page);
+ /* See gmap_make_secure(): large folios cannot be secure */
+ if (unlikely(folio_test_large(folio)))
+ return 0;
+
+ folio_get(folio);
rc = uv_destroy_page(paddr);
if (!rc)
- clear_bit(PG_arch_1, &page->flags);
- put_page(page);
+ clear_bit(PG_arch_1, &folio->flags);
+ folio_put(folio);
return rc;
}
@@ -170,14 +174,18 @@ int uv_convert_from_secure(unsigned long paddr)
*/
int uv_convert_owned_from_secure(unsigned long paddr)
{
- struct page *page = phys_to_page(paddr);
+ struct folio *folio = phys_to_folio(paddr);
int rc;
- get_page(page);
+ /* See gmap_make_secure(): large folios cannot be secure */
+ if (unlikely(folio_test_large(folio)))
+ return 0;
+
+ folio_get(folio);
rc = uv_convert_from_secure(paddr);
if (!rc)
- clear_bit(PG_arch_1, &page->flags);
- put_page(page);
+ clear_bit(PG_arch_1, &folio->flags);
+ folio_put(folio);
return rc;
}
@@ -479,33 +487,34 @@ EXPORT_SYMBOL_GPL(gmap_destroy_page);
*/
int arch_make_page_accessible(struct page *page)
{
+ struct folio *folio = page_folio(page);
int rc = 0;
- /* Hugepage cannot be protected, so nothing to do */
- if (PageHuge(page))
+ /* See gmap_make_secure(): large folios cannot be secure */
+ if (unlikely(folio_test_large(folio)))
return 0;
/*
* PG_arch_1 is used in 3 places:
* 1. for kernel page tables during early boot
* 2. for storage keys of huge pages and KVM
- * 3. As an indication that this page might be secure. This can
+ * 3. As an indication that this small folio might be secure. This can
* overindicate, e.g. we set the bit before calling
* convert_to_secure.
* As secure pages are never huge, all 3 variants can co-exists.
*/
- if (!test_bit(PG_arch_1, &page->flags))
+ if (!test_bit(PG_arch_1, &folio->flags))
return 0;
- rc = uv_pin_shared(page_to_phys(page));
+ rc = uv_pin_shared(folio_to_phys(folio));
if (!rc) {
- clear_bit(PG_arch_1, &page->flags);
+ clear_bit(PG_arch_1, &folio->flags);
return 0;
}
- rc = uv_convert_from_secure(page_to_phys(page));
+ rc = uv_convert_from_secure(folio_to_phys(folio));
if (!rc) {
- clear_bit(PG_arch_1, &page->flags);
+ clear_bit(PG_arch_1, &folio->flags);
return 0;
}
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* Re: [PATCH v2 04/10] s390/uv: convert PG_arch_1 users to only work on small folios
2024-04-12 14:21 ` [PATCH v2 04/10] s390/uv: convert PG_arch_1 users to only work on small folios David Hildenbrand
@ 2024-05-07 15:49 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 15:49 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Fri, 12 Apr 2024 16:21:14 +0200
David Hildenbrand <david@redhat.com> wrote:
> Now that make_folio_secure() may only set PG_arch_1 for small folios,
> let's convert relevant remaining UV code to only work on (small) folios
> and simply reject large folios early. This way, we'll never end up
> touching PG_arch_1 on tail pages of a large folio in UV code.
>
> The folio_get()/folio_put() for functions that are documented to already
> hold a folio reference look weird; likely they are required to make
> concurrent gmap_make_secure() back off because the caller might only hold
> an implicit reference due to the page mapping. So leave that alone for now.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> arch/s390/include/asm/page.h | 2 ++
> arch/s390/kernel/uv.c | 41 ++++++++++++++++++++++--------------
> 2 files changed, 27 insertions(+), 16 deletions(-)
>
> diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
> index 9381879f7ecf..b64384872c0f 100644
> --- a/arch/s390/include/asm/page.h
> +++ b/arch/s390/include/asm/page.h
> @@ -214,7 +214,9 @@ static inline unsigned long __phys_addr(unsigned long x, bool is_31bit)
> #define pfn_to_phys(pfn) ((pfn) << PAGE_SHIFT)
>
> #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
> +#define phys_to_folio(phys) page_folio(phys_to_page(phys))
> #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
> +#define folio_to_phys(page) pfn_to_phys(folio_pfn(folio))
>
> static inline void *pfn_to_virt(unsigned long pfn)
> {
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index 3c6d86e3e828..914dcec27329 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -135,14 +135,18 @@ static int uv_destroy_page(unsigned long paddr)
> */
> int uv_destroy_owned_page(unsigned long paddr)
> {
> - struct page *page = phys_to_page(paddr);
> + struct folio *folio = phys_to_folio(paddr);
> int rc;
>
> - get_page(page);
> + /* See gmap_make_secure(): large folios cannot be secure */
> + if (unlikely(folio_test_large(folio)))
> + return 0;
> +
> + folio_get(folio);
> rc = uv_destroy_page(paddr);
> if (!rc)
> - clear_bit(PG_arch_1, &page->flags);
> - put_page(page);
> + clear_bit(PG_arch_1, &folio->flags);
> + folio_put(folio);
> return rc;
> }
>
> @@ -170,14 +174,18 @@ int uv_convert_from_secure(unsigned long paddr)
> */
> int uv_convert_owned_from_secure(unsigned long paddr)
> {
> - struct page *page = phys_to_page(paddr);
> + struct folio *folio = phys_to_folio(paddr);
> int rc;
>
> - get_page(page);
> + /* See gmap_make_secure(): large folios cannot be secure */
> + if (unlikely(folio_test_large(folio)))
> + return 0;
> +
> + folio_get(folio);
> rc = uv_convert_from_secure(paddr);
> if (!rc)
> - clear_bit(PG_arch_1, &page->flags);
> - put_page(page);
> + clear_bit(PG_arch_1, &folio->flags);
> + folio_put(folio);
> return rc;
> }
>
> @@ -479,33 +487,34 @@ EXPORT_SYMBOL_GPL(gmap_destroy_page);
> */
> int arch_make_page_accessible(struct page *page)
> {
> + struct folio *folio = page_folio(page);
> int rc = 0;
>
> - /* Hugepage cannot be protected, so nothing to do */
> - if (PageHuge(page))
> + /* See gmap_make_secure(): large folios cannot be secure */
> + if (unlikely(folio_test_large(folio)))
> return 0;
>
> /*
> * PG_arch_1 is used in 3 places:
> * 1. for kernel page tables during early boot
> * 2. for storage keys of huge pages and KVM
> - * 3. As an indication that this page might be secure. This can
> + * 3. As an indication that this small folio might be secure. This can
> * overindicate, e.g. we set the bit before calling
> * convert_to_secure.
> * As secure pages are never huge, all 3 variants can co-exists.
> */
> - if (!test_bit(PG_arch_1, &page->flags))
> + if (!test_bit(PG_arch_1, &folio->flags))
> return 0;
>
> - rc = uv_pin_shared(page_to_phys(page));
> + rc = uv_pin_shared(folio_to_phys(folio));
> if (!rc) {
> - clear_bit(PG_arch_1, &page->flags);
> + clear_bit(PG_arch_1, &folio->flags);
> return 0;
> }
>
> - rc = uv_convert_from_secure(page_to_phys(page));
> + rc = uv_convert_from_secure(folio_to_phys(folio));
> if (!rc) {
> - clear_bit(PG_arch_1, &page->flags);
> + clear_bit(PG_arch_1, &folio->flags);
> return 0;
> }
>
^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 05/10] s390/uv: update PG_arch_1 comment
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
` (3 preceding siblings ...)
2024-04-12 14:21 ` [PATCH v2 04/10] s390/uv: convert PG_arch_1 users to only work on small folios David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-04-12 14:21 ` [PATCH v2 06/10] s390/uv: make uv_convert_from_secure() a static function David Hildenbrand
` (5 subsequent siblings)
10 siblings, 0 replies; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
We removed the usage of PG_arch_1 for page tables in commit
a51324c430db ("s390/cmma: rework no-dat handling").
Let's update the comment in UV to reflect that.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/kernel/uv.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 914dcec27329..ecfc08902215 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -495,13 +495,12 @@ int arch_make_page_accessible(struct page *page)
return 0;
/*
- * PG_arch_1 is used in 3 places:
- * 1. for kernel page tables during early boot
- * 2. for storage keys of huge pages and KVM
- * 3. As an indication that this small folio might be secure. This can
+ * PG_arch_1 is used in 2 places:
+ * 1. for storage keys of hugetlb folios and KVM
+ * 2. As an indication that this small folio might be secure. This can
* overindicate, e.g. we set the bit before calling
* convert_to_secure.
- * As secure pages are never huge, all 3 variants can co-exists.
+ * As secure pages are never large folios, both variants can co-exists.
*/
if (!test_bit(PG_arch_1, &folio->flags))
return 0;
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* [PATCH v2 06/10] s390/uv: make uv_convert_from_secure() a static function
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
` (4 preceding siblings ...)
2024-04-12 14:21 ` [PATCH v2 05/10] s390/uv: update PG_arch_1 comment David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-05-07 15:53 ` Claudio Imbrenda
2024-04-12 14:21 ` [PATCH v2 07/10] s390/uv: convert uv_destroy_owned_page() to uv_destroy_(folio|pte)() David Hildenbrand
` (4 subsequent siblings)
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
It's not used outside of uv.c, so let's make it a static function.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/include/asm/uv.h | 6 ------
arch/s390/kernel/uv.c | 2 +-
2 files changed, 1 insertion(+), 7 deletions(-)
diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index 0e7bd3873907..d2205ff97007 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -484,7 +484,6 @@ int uv_pin_shared(unsigned long paddr);
int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
int uv_destroy_owned_page(unsigned long paddr);
-int uv_convert_from_secure(unsigned long paddr);
int uv_convert_owned_from_secure(unsigned long paddr);
int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
@@ -503,11 +502,6 @@ static inline int uv_destroy_owned_page(unsigned long paddr)
return 0;
}
-static inline int uv_convert_from_secure(unsigned long paddr)
-{
- return 0;
-}
-
static inline int uv_convert_owned_from_secure(unsigned long paddr)
{
return 0;
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index ecfc08902215..3d3250b406a6 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -156,7 +156,7 @@ int uv_destroy_owned_page(unsigned long paddr)
*
* @paddr: Absolute host address of page to be exported
*/
-int uv_convert_from_secure(unsigned long paddr)
+static int uv_convert_from_secure(unsigned long paddr)
{
struct uv_cb_cfs uvcb = {
.header.cmd = UVC_CMD_CONV_FROM_SEC_STOR,
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* Re: [PATCH v2 06/10] s390/uv: make uv_convert_from_secure() a static function
2024-04-12 14:21 ` [PATCH v2 06/10] s390/uv: make uv_convert_from_secure() a static function David Hildenbrand
@ 2024-05-07 15:53 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 15:53 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Fri, 12 Apr 2024 16:21:16 +0200
David Hildenbrand <david@redhat.com> wrote:
> It's not used outside of uv.c, so let's make it a static function.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> arch/s390/include/asm/uv.h | 6 ------
> arch/s390/kernel/uv.c | 2 +-
> 2 files changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
> index 0e7bd3873907..d2205ff97007 100644
> --- a/arch/s390/include/asm/uv.h
> +++ b/arch/s390/include/asm/uv.h
> @@ -484,7 +484,6 @@ int uv_pin_shared(unsigned long paddr);
> int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
> int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
> int uv_destroy_owned_page(unsigned long paddr);
> -int uv_convert_from_secure(unsigned long paddr);
> int uv_convert_owned_from_secure(unsigned long paddr);
> int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
>
> @@ -503,11 +502,6 @@ static inline int uv_destroy_owned_page(unsigned long paddr)
> return 0;
> }
>
> -static inline int uv_convert_from_secure(unsigned long paddr)
> -{
> - return 0;
> -}
> -
> static inline int uv_convert_owned_from_secure(unsigned long paddr)
> {
> return 0;
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index ecfc08902215..3d3250b406a6 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -156,7 +156,7 @@ int uv_destroy_owned_page(unsigned long paddr)
> *
> * @paddr: Absolute host address of page to be exported
> */
> -int uv_convert_from_secure(unsigned long paddr)
> +static int uv_convert_from_secure(unsigned long paddr)
> {
> struct uv_cb_cfs uvcb = {
> .header.cmd = UVC_CMD_CONV_FROM_SEC_STOR,
^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 07/10] s390/uv: convert uv_destroy_owned_page() to uv_destroy_(folio|pte)()
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
` (5 preceding siblings ...)
2024-04-12 14:21 ` [PATCH v2 06/10] s390/uv: make uv_convert_from_secure() a static function David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-05-07 16:25 ` Claudio Imbrenda
2024-04-12 14:21 ` [PATCH v2 08/10] s390/uv: convert uv_convert_owned_from_secure() to uv_convert_from_secure_(folio|pte)() David Hildenbrand
` (3 subsequent siblings)
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
Let's have the following variants for destroying pages:
(1) uv_destroy(): Like uv_pin_shared() and uv_convert_from_secure(),
"low level" helper that operates on paddr and doesn't mess with folios.
(2) uv_destroy_folio(): Consumes a folio to which we hold a reference.
(3) uv_destroy_pte(): Consumes a PTE that holds a reference through the
mapping.
Unfortunately we need uv_destroy_pte(), because pfn_folio() and
friends are not available in pgtable.h.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/include/asm/pgtable.h | 2 +-
arch/s390/include/asm/uv.h | 10 ++++++++--
arch/s390/kernel/uv.c | 24 +++++++++++++++++-------
arch/s390/mm/gmap.c | 6 ++++--
4 files changed, 30 insertions(+), 12 deletions(-)
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 60950e7a25f5..97e040617c29 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1199,7 +1199,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
* The notifier should have destroyed all protected vCPUs at this
* point, so the destroy should be successful.
*/
- if (full && !uv_destroy_owned_page(pte_val(res) & PAGE_MASK))
+ if (full && !uv_destroy_pte(res))
return res;
/*
* If something went wrong and the page could not be destroyed, or
diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index d2205ff97007..a1bef30066ef 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -483,7 +483,8 @@ static inline int is_prot_virt_host(void)
int uv_pin_shared(unsigned long paddr);
int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
-int uv_destroy_owned_page(unsigned long paddr);
+int uv_destroy_folio(struct folio *folio);
+int uv_destroy_pte(pte_t pte);
int uv_convert_owned_from_secure(unsigned long paddr);
int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
@@ -497,7 +498,12 @@ static inline int uv_pin_shared(unsigned long paddr)
return 0;
}
-static inline int uv_destroy_owned_page(unsigned long paddr)
+static inline int uv_destroy_folio(struct folio *folio)
+{
+ return 0;
+}
+
+static inline int uv_destroy_pte(pte_t pte)
{
return 0;
}
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 3d3250b406a6..61c1ce51c883 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -110,7 +110,7 @@ EXPORT_SYMBOL_GPL(uv_pin_shared);
*
* @paddr: Absolute host address of page to be destroyed
*/
-static int uv_destroy_page(unsigned long paddr)
+static int uv_destroy(unsigned long paddr)
{
struct uv_cb_cfs uvcb = {
.header.cmd = UVC_CMD_DESTR_SEC_STOR,
@@ -131,11 +131,10 @@ static int uv_destroy_page(unsigned long paddr)
}
/*
- * The caller must already hold a reference to the page
+ * The caller must already hold a reference to the folio
*/
-int uv_destroy_owned_page(unsigned long paddr)
+int uv_destroy_folio(struct folio *folio)
{
- struct folio *folio = phys_to_folio(paddr);
int rc;
/* See gmap_make_secure(): large folios cannot be secure */
@@ -143,13 +142,22 @@ int uv_destroy_owned_page(unsigned long paddr)
return 0;
folio_get(folio);
- rc = uv_destroy_page(paddr);
+ rc = uv_destroy(folio_to_phys(folio));
if (!rc)
clear_bit(PG_arch_1, &folio->flags);
folio_put(folio);
return rc;
}
+/*
+ * The present PTE still indirectly holds a folio reference through the mapping.
+ */
+int uv_destroy_pte(pte_t pte)
+{
+ VM_WARN_ON(!pte_present(pte));
+ return uv_destroy_folio(pfn_folio(pte_pfn(pte)));
+}
+
/*
* Requests the Ultravisor to encrypt a guest page and make it
* accessible to the host for paging (export).
@@ -437,6 +445,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
{
struct vm_area_struct *vma;
unsigned long uaddr;
+ struct folio *folio;
struct page *page;
int rc;
@@ -460,7 +469,8 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
page = follow_page(vma, uaddr, FOLL_WRITE | FOLL_GET);
if (IS_ERR_OR_NULL(page))
goto out;
- rc = uv_destroy_owned_page(page_to_phys(page));
+ folio = page_folio(page);
+ rc = uv_destroy_folio(folio);
/*
* Fault handlers can race; it is possible that two CPUs will fault
* on the same secure page. One CPU can destroy the page, reboot,
@@ -472,7 +482,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
*/
if (rc)
rc = uv_convert_owned_from_secure(page_to_phys(page));
- put_page(page);
+ folio_put(folio);
out:
mmap_read_unlock(gmap->mm);
return rc;
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 094b43b121cd..0351cb139df4 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2756,13 +2756,15 @@ static const struct mm_walk_ops gather_pages_ops = {
*/
void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns)
{
+ struct folio *folio;
unsigned long i;
for (i = 0; i < count; i++) {
+ folio = pfn_folio(pfns[i]);
/* we always have an extra reference */
- uv_destroy_owned_page(pfn_to_phys(pfns[i]));
+ uv_destroy_folio(folio);
/* get rid of the extra reference */
- put_page(pfn_to_page(pfns[i]));
+ folio_put(folio);
cond_resched();
}
}
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* Re: [PATCH v2 07/10] s390/uv: convert uv_destroy_owned_page() to uv_destroy_(folio|pte)()
2024-04-12 14:21 ` [PATCH v2 07/10] s390/uv: convert uv_destroy_owned_page() to uv_destroy_(folio|pte)() David Hildenbrand
@ 2024-05-07 16:25 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 16:25 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Fri, 12 Apr 2024 16:21:17 +0200
David Hildenbrand <david@redhat.com> wrote:
> Let's have the following variants for destroying pages:
>
> (1) uv_destroy(): Like uv_pin_shared() and uv_convert_from_secure(),
> "low level" helper that operates on paddr and doesn't mess with folios.
>
> (2) uv_destroy_folio(): Consumes a folio to which we hold a reference.
>
> (3) uv_destroy_pte(): Consumes a PTE that holds a reference through the
> mapping.
>
> Unfortunately we need uv_destroy_pte(), because pfn_folio() and
> friends are not available in pgtable.h.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> arch/s390/include/asm/pgtable.h | 2 +-
> arch/s390/include/asm/uv.h | 10 ++++++++--
> arch/s390/kernel/uv.c | 24 +++++++++++++++++-------
> arch/s390/mm/gmap.c | 6 ++++--
> 4 files changed, 30 insertions(+), 12 deletions(-)
>
> diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
> index 60950e7a25f5..97e040617c29 100644
> --- a/arch/s390/include/asm/pgtable.h
> +++ b/arch/s390/include/asm/pgtable.h
> @@ -1199,7 +1199,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
> * The notifier should have destroyed all protected vCPUs at this
> * point, so the destroy should be successful.
> */
> - if (full && !uv_destroy_owned_page(pte_val(res) & PAGE_MASK))
> + if (full && !uv_destroy_pte(res))
> return res;
> /*
> * If something went wrong and the page could not be destroyed, or
> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
> index d2205ff97007..a1bef30066ef 100644
> --- a/arch/s390/include/asm/uv.h
> +++ b/arch/s390/include/asm/uv.h
> @@ -483,7 +483,8 @@ static inline int is_prot_virt_host(void)
> int uv_pin_shared(unsigned long paddr);
> int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
> int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
> -int uv_destroy_owned_page(unsigned long paddr);
> +int uv_destroy_folio(struct folio *folio);
> +int uv_destroy_pte(pte_t pte);
> int uv_convert_owned_from_secure(unsigned long paddr);
> int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
>
> @@ -497,7 +498,12 @@ static inline int uv_pin_shared(unsigned long paddr)
> return 0;
> }
>
> -static inline int uv_destroy_owned_page(unsigned long paddr)
> +static inline int uv_destroy_folio(struct folio *folio)
> +{
> + return 0;
> +}
> +
> +static inline int uv_destroy_pte(pte_t pte)
> {
> return 0;
> }
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index 3d3250b406a6..61c1ce51c883 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -110,7 +110,7 @@ EXPORT_SYMBOL_GPL(uv_pin_shared);
> *
> * @paddr: Absolute host address of page to be destroyed
> */
> -static int uv_destroy_page(unsigned long paddr)
> +static int uv_destroy(unsigned long paddr)
> {
> struct uv_cb_cfs uvcb = {
> .header.cmd = UVC_CMD_DESTR_SEC_STOR,
> @@ -131,11 +131,10 @@ static int uv_destroy_page(unsigned long paddr)
> }
>
> /*
> - * The caller must already hold a reference to the page
> + * The caller must already hold a reference to the folio
> */
> -int uv_destroy_owned_page(unsigned long paddr)
> +int uv_destroy_folio(struct folio *folio)
> {
> - struct folio *folio = phys_to_folio(paddr);
> int rc;
>
> /* See gmap_make_secure(): large folios cannot be secure */
> @@ -143,13 +142,22 @@ int uv_destroy_owned_page(unsigned long paddr)
> return 0;
>
> folio_get(folio);
> - rc = uv_destroy_page(paddr);
> + rc = uv_destroy(folio_to_phys(folio));
> if (!rc)
> clear_bit(PG_arch_1, &folio->flags);
> folio_put(folio);
> return rc;
> }
>
> +/*
> + * The present PTE still indirectly holds a folio reference through the mapping.
> + */
> +int uv_destroy_pte(pte_t pte)
> +{
> + VM_WARN_ON(!pte_present(pte));
> + return uv_destroy_folio(pfn_folio(pte_pfn(pte)));
> +}
> +
> /*
> * Requests the Ultravisor to encrypt a guest page and make it
> * accessible to the host for paging (export).
> @@ -437,6 +445,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
> {
> struct vm_area_struct *vma;
> unsigned long uaddr;
> + struct folio *folio;
> struct page *page;
> int rc;
>
> @@ -460,7 +469,8 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
> page = follow_page(vma, uaddr, FOLL_WRITE | FOLL_GET);
> if (IS_ERR_OR_NULL(page))
> goto out;
> - rc = uv_destroy_owned_page(page_to_phys(page));
> + folio = page_folio(page);
> + rc = uv_destroy_folio(folio);
> /*
> * Fault handlers can race; it is possible that two CPUs will fault
> * on the same secure page. One CPU can destroy the page, reboot,
> @@ -472,7 +482,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
> */
> if (rc)
> rc = uv_convert_owned_from_secure(page_to_phys(page));
> - put_page(page);
> + folio_put(folio);
> out:
> mmap_read_unlock(gmap->mm);
> return rc;
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 094b43b121cd..0351cb139df4 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -2756,13 +2756,15 @@ static const struct mm_walk_ops gather_pages_ops = {
> */
> void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns)
> {
> + struct folio *folio;
> unsigned long i;
>
> for (i = 0; i < count; i++) {
> + folio = pfn_folio(pfns[i]);
> /* we always have an extra reference */
> - uv_destroy_owned_page(pfn_to_phys(pfns[i]));
> + uv_destroy_folio(folio);
> /* get rid of the extra reference */
> - put_page(pfn_to_page(pfns[i]));
> + folio_put(folio);
> cond_resched();
> }
> }
^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 08/10] s390/uv: convert uv_convert_owned_from_secure() to uv_convert_from_secure_(folio|pte)()
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
` (6 preceding siblings ...)
2024-04-12 14:21 ` [PATCH v2 07/10] s390/uv: convert uv_destroy_owned_page() to uv_destroy_(folio|pte)() David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-05-07 16:26 ` Claudio Imbrenda
2024-04-12 14:21 ` [PATCH v2 09/10] s390/uv: implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE David Hildenbrand
` (2 subsequent siblings)
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
Let's do the same as we did for uv_destroy_(folio|pte)() and
have the following variants:
(1) uv_convert_from_secure(): "low level" helper that operates on paddr
and does not mess with folios.
(2) uv_convert_from_secure_folio(): Consumes a folio to which we hold a
reference.
(3) uv_convert_from_secure_pte(): Consumes a PTE that holds a reference
through the mapping.
Unfortunately we need uv_convert_from_secure_pte(), because pfn_folio()
and friends are not available in pgtable.h.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/include/asm/pgtable.h | 6 +++---
arch/s390/include/asm/uv.h | 4 ++--
arch/s390/kernel/uv.c | 18 +++++++++++++-----
3 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 97e040617c29..5ffc4828c25a 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1149,7 +1149,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
res = ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID));
/* At this point the reference through the mapping is still present */
if (mm_is_protected(mm) && pte_present(res))
- uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
+ uv_convert_from_secure_pte(res);
return res;
}
@@ -1167,7 +1167,7 @@ static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
res = ptep_xchg_direct(vma->vm_mm, addr, ptep, __pte(_PAGE_INVALID));
/* At this point the reference through the mapping is still present */
if (mm_is_protected(vma->vm_mm) && pte_present(res))
- uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
+ uv_convert_from_secure_pte(res);
return res;
}
@@ -1206,7 +1206,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
* if this is not a mm teardown, the slower export is used as
* fallback instead.
*/
- uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
+ uv_convert_from_secure_pte(res);
return res;
}
diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
index a1bef30066ef..0679445cac0b 100644
--- a/arch/s390/include/asm/uv.h
+++ b/arch/s390/include/asm/uv.h
@@ -485,7 +485,7 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
int uv_destroy_folio(struct folio *folio);
int uv_destroy_pte(pte_t pte);
-int uv_convert_owned_from_secure(unsigned long paddr);
+int uv_convert_from_secure_pte(pte_t pte);
int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
void setup_uv(void);
@@ -508,7 +508,7 @@ static inline int uv_destroy_pte(pte_t pte)
return 0;
}
-static inline int uv_convert_owned_from_secure(unsigned long paddr)
+static inline int uv_convert_from_secure_pte(pte_t pte)
{
return 0;
}
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 61c1ce51c883..b456066d72da 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -178,11 +178,10 @@ static int uv_convert_from_secure(unsigned long paddr)
}
/*
- * The caller must already hold a reference to the page
+ * The caller must already hold a reference to the folio.
*/
-int uv_convert_owned_from_secure(unsigned long paddr)
+static int uv_convert_from_secure_folio(struct folio *folio)
{
- struct folio *folio = phys_to_folio(paddr);
int rc;
/* See gmap_make_secure(): large folios cannot be secure */
@@ -190,13 +189,22 @@ int uv_convert_owned_from_secure(unsigned long paddr)
return 0;
folio_get(folio);
- rc = uv_convert_from_secure(paddr);
+ rc = uv_convert_from_secure(folio_to_phys(folio));
if (!rc)
clear_bit(PG_arch_1, &folio->flags);
folio_put(folio);
return rc;
}
+/*
+ * The present PTE still indirectly holds a folio reference through the mapping.
+ */
+int uv_convert_from_secure_pte(pte_t pte)
+{
+ VM_WARN_ON(!pte_present(pte));
+ return uv_convert_from_secure_folio(pfn_folio(pte_pfn(pte)));
+}
+
/*
* Calculate the expected ref_count for a folio that would otherwise have no
* further pins. This was cribbed from similar functions in other places in
@@ -481,7 +489,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
* we instead try to export the page.
*/
if (rc)
- rc = uv_convert_owned_from_secure(page_to_phys(page));
+ rc = uv_convert_from_secure_folio(folio);
folio_put(folio);
out:
mmap_read_unlock(gmap->mm);
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* Re: [PATCH v2 08/10] s390/uv: convert uv_convert_owned_from_secure() to uv_convert_from_secure_(folio|pte)()
2024-04-12 14:21 ` [PATCH v2 08/10] s390/uv: convert uv_convert_owned_from_secure() to uv_convert_from_secure_(folio|pte)() David Hildenbrand
@ 2024-05-07 16:26 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 16:26 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Fri, 12 Apr 2024 16:21:18 +0200
David Hildenbrand <david@redhat.com> wrote:
> Let's do the same as we did for uv_destroy_(folio|pte)() and
> have the following variants:
>
> (1) uv_convert_from_secure(): "low level" helper that operates on paddr
> and does not mess with folios.
>
> (2) uv_convert_from_secure_folio(): Consumes a folio to which we hold a
> reference.
>
> (3) uv_convert_from_secure_pte(): Consumes a PTE that holds a reference
> through the mapping.
>
> Unfortunately we need uv_convert_from_secure_pte(), because pfn_folio()
> and friends are not available in pgtable.h.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> arch/s390/include/asm/pgtable.h | 6 +++---
> arch/s390/include/asm/uv.h | 4 ++--
> arch/s390/kernel/uv.c | 18 +++++++++++++-----
> 3 files changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
> index 97e040617c29..5ffc4828c25a 100644
> --- a/arch/s390/include/asm/pgtable.h
> +++ b/arch/s390/include/asm/pgtable.h
> @@ -1149,7 +1149,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
> res = ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID));
> /* At this point the reference through the mapping is still present */
> if (mm_is_protected(mm) && pte_present(res))
> - uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
> + uv_convert_from_secure_pte(res);
> return res;
> }
>
> @@ -1167,7 +1167,7 @@ static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
> res = ptep_xchg_direct(vma->vm_mm, addr, ptep, __pte(_PAGE_INVALID));
> /* At this point the reference through the mapping is still present */
> if (mm_is_protected(vma->vm_mm) && pte_present(res))
> - uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
> + uv_convert_from_secure_pte(res);
> return res;
> }
>
> @@ -1206,7 +1206,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
> * if this is not a mm teardown, the slower export is used as
> * fallback instead.
> */
> - uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
> + uv_convert_from_secure_pte(res);
> return res;
> }
>
> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
> index a1bef30066ef..0679445cac0b 100644
> --- a/arch/s390/include/asm/uv.h
> +++ b/arch/s390/include/asm/uv.h
> @@ -485,7 +485,7 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
> int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
> int uv_destroy_folio(struct folio *folio);
> int uv_destroy_pte(pte_t pte);
> -int uv_convert_owned_from_secure(unsigned long paddr);
> +int uv_convert_from_secure_pte(pte_t pte);
> int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
>
> void setup_uv(void);
> @@ -508,7 +508,7 @@ static inline int uv_destroy_pte(pte_t pte)
> return 0;
> }
>
> -static inline int uv_convert_owned_from_secure(unsigned long paddr)
> +static inline int uv_convert_from_secure_pte(pte_t pte)
> {
> return 0;
> }
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index 61c1ce51c883..b456066d72da 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -178,11 +178,10 @@ static int uv_convert_from_secure(unsigned long paddr)
> }
>
> /*
> - * The caller must already hold a reference to the page
> + * The caller must already hold a reference to the folio.
> */
> -int uv_convert_owned_from_secure(unsigned long paddr)
> +static int uv_convert_from_secure_folio(struct folio *folio)
> {
> - struct folio *folio = phys_to_folio(paddr);
> int rc;
>
> /* See gmap_make_secure(): large folios cannot be secure */
> @@ -190,13 +189,22 @@ int uv_convert_owned_from_secure(unsigned long paddr)
> return 0;
>
> folio_get(folio);
> - rc = uv_convert_from_secure(paddr);
> + rc = uv_convert_from_secure(folio_to_phys(folio));
> if (!rc)
> clear_bit(PG_arch_1, &folio->flags);
> folio_put(folio);
> return rc;
> }
>
> +/*
> + * The present PTE still indirectly holds a folio reference through the mapping.
> + */
> +int uv_convert_from_secure_pte(pte_t pte)
> +{
> + VM_WARN_ON(!pte_present(pte));
> + return uv_convert_from_secure_folio(pfn_folio(pte_pfn(pte)));
> +}
> +
> /*
> * Calculate the expected ref_count for a folio that would otherwise have no
> * further pins. This was cribbed from similar functions in other places in
> @@ -481,7 +489,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
> * we instead try to export the page.
> */
> if (rc)
> - rc = uv_convert_owned_from_secure(page_to_phys(page));
> + rc = uv_convert_from_secure_folio(folio);
> folio_put(folio);
> out:
> mmap_read_unlock(gmap->mm);
^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 09/10] s390/uv: implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
` (7 preceding siblings ...)
2024-04-12 14:21 ` [PATCH v2 08/10] s390/uv: convert uv_convert_owned_from_secure() to uv_convert_from_secure_(folio|pte)() David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-05-07 16:29 ` Claudio Imbrenda
2024-04-12 14:21 ` [PATCH v2 10/10] s390/hugetlb: convert PG_arch_1 code to work on folio->flags David Hildenbrand
2024-04-30 18:49 ` [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
Let's also implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE, so we can convert
arch_make_page_accessible() to be a simple wrapper around
arch_make_folio_accessible(). Unfortuantely, we cannot do that in the
header.
There are only two arch_make_page_accessible() calls remaining in gup.c.
We can now drop HAVE_ARCH_MAKE_PAGE_ACCESSIBLE completely form core-MM.
We'll handle that separately, once the s390x part landed.
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/include/asm/page.h | 3 +++
arch/s390/kernel/uv.c | 18 +++++++++++-------
arch/s390/mm/fault.c | 14 ++++++++------
3 files changed, 22 insertions(+), 13 deletions(-)
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index b64384872c0f..03bbc782e286 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -162,6 +162,7 @@ static inline int page_reset_referenced(unsigned long addr)
#define _PAGE_ACC_BITS 0xf0 /* HW access control bits */
struct page;
+struct folio;
void arch_free_page(struct page *page, int order);
void arch_alloc_page(struct page *page, int order);
@@ -174,6 +175,8 @@ static inline int devmem_is_allowed(unsigned long pfn)
#define HAVE_ARCH_ALLOC_PAGE
#if IS_ENABLED(CONFIG_PGSTE)
+int arch_make_folio_accessible(struct folio *folio);
+#define HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
int arch_make_page_accessible(struct page *page);
#define HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
#endif
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index b456066d72da..fa62fa0e369f 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -498,14 +498,13 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
EXPORT_SYMBOL_GPL(gmap_destroy_page);
/*
- * To be called with the page locked or with an extra reference! This will
- * prevent gmap_make_secure from touching the page concurrently. Having 2
- * parallel make_page_accessible is fine, as the UV calls will become a
- * no-op if the page is already exported.
+ * To be called with the folio locked or with an extra reference! This will
+ * prevent gmap_make_secure from touching the folio concurrently. Having 2
+ * parallel arch_make_folio_accessible is fine, as the UV calls will become a
+ * no-op if the folio is already exported.
*/
-int arch_make_page_accessible(struct page *page)
+int arch_make_folio_accessible(struct folio *folio)
{
- struct folio *folio = page_folio(page);
int rc = 0;
/* See gmap_make_secure(): large folios cannot be secure */
@@ -537,8 +536,13 @@ int arch_make_page_accessible(struct page *page)
return rc;
}
-EXPORT_SYMBOL_GPL(arch_make_page_accessible);
+EXPORT_SYMBOL_GPL(arch_make_folio_accessible);
+int arch_make_page_accessible(struct page *page)
+{
+ return arch_make_folio_accessible(page_folio(page));
+}
+EXPORT_SYMBOL_GPL(arch_make_page_accessible);
#endif
#if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) || IS_ENABLED(CONFIG_KVM)
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index c421dd44ffbe..a1ba58460593 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -491,6 +491,7 @@ void do_secure_storage_access(struct pt_regs *regs)
unsigned long addr = get_fault_address(regs);
struct vm_area_struct *vma;
struct mm_struct *mm;
+ struct folio *folio;
struct page *page;
struct gmap *gmap;
int rc;
@@ -538,17 +539,18 @@ void do_secure_storage_access(struct pt_regs *regs)
mmap_read_unlock(mm);
break;
}
- if (arch_make_page_accessible(page))
+ folio = page_folio(page);
+ if (arch_make_folio_accessible(folio))
send_sig(SIGSEGV, current, 0);
- put_page(page);
+ folio_put(folio);
mmap_read_unlock(mm);
break;
case KERNEL_FAULT:
- page = phys_to_page(addr);
- if (unlikely(!try_get_page(page)))
+ folio = phys_to_folio(addr);
+ if (unlikely(!folio_try_get(folio)))
break;
- rc = arch_make_page_accessible(page);
- put_page(page);
+ rc = arch_make_folio_accessible(folio);
+ folio_put(folio);
if (rc)
BUG();
break;
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* Re: [PATCH v2 09/10] s390/uv: implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
2024-04-12 14:21 ` [PATCH v2 09/10] s390/uv: implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE David Hildenbrand
@ 2024-05-07 16:29 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 16:29 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Fri, 12 Apr 2024 16:21:19 +0200
David Hildenbrand <david@redhat.com> wrote:
> Let's also implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE, so we can convert
> arch_make_page_accessible() to be a simple wrapper around
> arch_make_folio_accessible(). Unfortuantely, we cannot do that in the
> header.
>
> There are only two arch_make_page_accessible() calls remaining in gup.c.
> We can now drop HAVE_ARCH_MAKE_PAGE_ACCESSIBLE completely form core-MM.
> We'll handle that separately, once the s390x part landed.
>
> Suggested-by: Matthew Wilcox <willy@infradead.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> arch/s390/include/asm/page.h | 3 +++
> arch/s390/kernel/uv.c | 18 +++++++++++-------
> arch/s390/mm/fault.c | 14 ++++++++------
> 3 files changed, 22 insertions(+), 13 deletions(-)
>
> diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
> index b64384872c0f..03bbc782e286 100644
> --- a/arch/s390/include/asm/page.h
> +++ b/arch/s390/include/asm/page.h
> @@ -162,6 +162,7 @@ static inline int page_reset_referenced(unsigned long addr)
> #define _PAGE_ACC_BITS 0xf0 /* HW access control bits */
>
> struct page;
> +struct folio;
> void arch_free_page(struct page *page, int order);
> void arch_alloc_page(struct page *page, int order);
>
> @@ -174,6 +175,8 @@ static inline int devmem_is_allowed(unsigned long pfn)
> #define HAVE_ARCH_ALLOC_PAGE
>
> #if IS_ENABLED(CONFIG_PGSTE)
> +int arch_make_folio_accessible(struct folio *folio);
> +#define HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
> int arch_make_page_accessible(struct page *page);
> #define HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
> #endif
> diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
> index b456066d72da..fa62fa0e369f 100644
> --- a/arch/s390/kernel/uv.c
> +++ b/arch/s390/kernel/uv.c
> @@ -498,14 +498,13 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
> EXPORT_SYMBOL_GPL(gmap_destroy_page);
>
> /*
> - * To be called with the page locked or with an extra reference! This will
> - * prevent gmap_make_secure from touching the page concurrently. Having 2
> - * parallel make_page_accessible is fine, as the UV calls will become a
> - * no-op if the page is already exported.
> + * To be called with the folio locked or with an extra reference! This will
> + * prevent gmap_make_secure from touching the folio concurrently. Having 2
> + * parallel arch_make_folio_accessible is fine, as the UV calls will become a
> + * no-op if the folio is already exported.
> */
> -int arch_make_page_accessible(struct page *page)
> +int arch_make_folio_accessible(struct folio *folio)
> {
> - struct folio *folio = page_folio(page);
> int rc = 0;
>
> /* See gmap_make_secure(): large folios cannot be secure */
> @@ -537,8 +536,13 @@ int arch_make_page_accessible(struct page *page)
>
> return rc;
> }
> -EXPORT_SYMBOL_GPL(arch_make_page_accessible);
> +EXPORT_SYMBOL_GPL(arch_make_folio_accessible);
>
> +int arch_make_page_accessible(struct page *page)
> +{
> + return arch_make_folio_accessible(page_folio(page));
> +}
> +EXPORT_SYMBOL_GPL(arch_make_page_accessible);
> #endif
>
> #if defined(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) || IS_ENABLED(CONFIG_KVM)
> diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
> index c421dd44ffbe..a1ba58460593 100644
> --- a/arch/s390/mm/fault.c
> +++ b/arch/s390/mm/fault.c
> @@ -491,6 +491,7 @@ void do_secure_storage_access(struct pt_regs *regs)
> unsigned long addr = get_fault_address(regs);
> struct vm_area_struct *vma;
> struct mm_struct *mm;
> + struct folio *folio;
> struct page *page;
> struct gmap *gmap;
> int rc;
> @@ -538,17 +539,18 @@ void do_secure_storage_access(struct pt_regs *regs)
> mmap_read_unlock(mm);
> break;
> }
> - if (arch_make_page_accessible(page))
> + folio = page_folio(page);
> + if (arch_make_folio_accessible(folio))
> send_sig(SIGSEGV, current, 0);
> - put_page(page);
> + folio_put(folio);
> mmap_read_unlock(mm);
> break;
> case KERNEL_FAULT:
> - page = phys_to_page(addr);
> - if (unlikely(!try_get_page(page)))
> + folio = phys_to_folio(addr);
> + if (unlikely(!folio_try_get(folio)))
> break;
> - rc = arch_make_page_accessible(page);
> - put_page(page);
> + rc = arch_make_folio_accessible(folio);
> + folio_put(folio);
> if (rc)
> BUG();
> break;
^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 10/10] s390/hugetlb: convert PG_arch_1 code to work on folio->flags
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
` (8 preceding siblings ...)
2024-04-12 14:21 ` [PATCH v2 09/10] s390/uv: implement HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE David Hildenbrand
@ 2024-04-12 14:21 ` David Hildenbrand
2024-05-07 16:33 ` Claudio Imbrenda
2024-04-30 18:49 ` [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-12 14:21 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, David Hildenbrand, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox,
Thomas Huth
Let's make it clearer that we are always working on folio flags and
never page flags of tail pages.
Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/s390/mm/gmap.c | 4 ++--
arch/s390/mm/hugetlbpage.c | 8 ++++----
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 0351cb139df4..9eea05cd93b7 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -2648,7 +2648,7 @@ static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
{
pmd_t *pmd = (pmd_t *)pte;
unsigned long start, end;
- struct page *page = pmd_page(*pmd);
+ struct folio *folio = page_folio(pmd_page(*pmd));
/*
* The write check makes sure we do not set a key on shared
@@ -2663,7 +2663,7 @@ static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
start = pmd_val(*pmd) & HPAGE_MASK;
end = start + HPAGE_SIZE - 1;
__storage_key_init_range(start, end);
- set_bit(PG_arch_1, &page->flags);
+ set_bit(PG_arch_1, &folio->flags);
cond_resched();
return 0;
}
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index c2e8242bd15d..a32047315f9a 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -121,7 +121,7 @@ static inline pte_t __rste_to_pte(unsigned long rste)
static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
{
- struct page *page;
+ struct folio *folio;
unsigned long size, paddr;
if (!mm_uses_skeys(mm) ||
@@ -129,16 +129,16 @@ static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
return;
if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
- page = pud_page(__pud(rste));
+ folio = page_folio(pud_page(__pud(rste)));
size = PUD_SIZE;
paddr = rste & PUD_MASK;
} else {
- page = pmd_page(__pmd(rste));
+ folio = page_folio(pmd_page(__pmd(rste)));
size = PMD_SIZE;
paddr = rste & PMD_MASK;
}
- if (!test_and_set_bit(PG_arch_1, &page->flags))
+ if (!test_and_set_bit(PG_arch_1, &folio->flags))
__storage_key_init_range(paddr, paddr + size - 1);
}
--
2.44.0
^ permalink raw reply related [flat|nested] 24+ messages in thread* Re: [PATCH v2 10/10] s390/hugetlb: convert PG_arch_1 code to work on folio->flags
2024-04-12 14:21 ` [PATCH v2 10/10] s390/hugetlb: convert PG_arch_1 code to work on folio->flags David Hildenbrand
@ 2024-05-07 16:33 ` Claudio Imbrenda
2024-05-08 18:08 ` David Hildenbrand
0 siblings, 1 reply; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 16:33 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Fri, 12 Apr 2024 16:21:20 +0200
David Hildenbrand <david@redhat.com> wrote:
> Let's make it clearer that we are always working on folio flags and
> never page flags of tail pages.
please be a little more verbose, and explain what you are doing (i.e.
converting usages of page flags to folio flags), not just why.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
with a few extra words in the description:
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
> arch/s390/mm/gmap.c | 4 ++--
> arch/s390/mm/hugetlbpage.c | 8 ++++----
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 0351cb139df4..9eea05cd93b7 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -2648,7 +2648,7 @@ static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
> {
> pmd_t *pmd = (pmd_t *)pte;
> unsigned long start, end;
> - struct page *page = pmd_page(*pmd);
> + struct folio *folio = page_folio(pmd_page(*pmd));
>
> /*
> * The write check makes sure we do not set a key on shared
> @@ -2663,7 +2663,7 @@ static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
> start = pmd_val(*pmd) & HPAGE_MASK;
> end = start + HPAGE_SIZE - 1;
> __storage_key_init_range(start, end);
> - set_bit(PG_arch_1, &page->flags);
> + set_bit(PG_arch_1, &folio->flags);
> cond_resched();
> return 0;
> }
> diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
> index c2e8242bd15d..a32047315f9a 100644
> --- a/arch/s390/mm/hugetlbpage.c
> +++ b/arch/s390/mm/hugetlbpage.c
> @@ -121,7 +121,7 @@ static inline pte_t __rste_to_pte(unsigned long rste)
>
> static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
> {
> - struct page *page;
> + struct folio *folio;
> unsigned long size, paddr;
>
> if (!mm_uses_skeys(mm) ||
> @@ -129,16 +129,16 @@ static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
> return;
>
> if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) {
> - page = pud_page(__pud(rste));
> + folio = page_folio(pud_page(__pud(rste)));
> size = PUD_SIZE;
> paddr = rste & PUD_MASK;
> } else {
> - page = pmd_page(__pmd(rste));
> + folio = page_folio(pmd_page(__pmd(rste)));
> size = PMD_SIZE;
> paddr = rste & PMD_MASK;
> }
>
> - if (!test_and_set_bit(PG_arch_1, &page->flags))
> + if (!test_and_set_bit(PG_arch_1, &folio->flags))
> __storage_key_init_range(paddr, paddr + size - 1);
> }
>
^ permalink raw reply [flat|nested] 24+ messages in thread* Re: [PATCH v2 10/10] s390/hugetlb: convert PG_arch_1 code to work on folio->flags
2024-05-07 16:33 ` Claudio Imbrenda
@ 2024-05-08 18:08 ` David Hildenbrand
2024-05-10 8:45 ` Claudio Imbrenda
0 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-05-08 18:08 UTC (permalink / raw)
To: Claudio Imbrenda
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On 07.05.24 18:33, Claudio Imbrenda wrote:
> On Fri, 12 Apr 2024 16:21:20 +0200
> David Hildenbrand <david@redhat.com> wrote:
>
>> Let's make it clearer that we are always working on folio flags and
>> never page flags of tail pages.
>
> please be a little more verbose, and explain what you are doing (i.e.
> converting usages of page flags to folio flags), not just why.
>
>>
>> Signed-off-by: David Hildenbrand <david@redhat.com>
>
> with a few extra words in the description:
Let's make it clearer that we are always working on folio flags and
never page flags of tail pages by converting remaining PG_arch_1 users
that modify page->flags to modify folio->flags instead.
No functional change intended, because we would always have worked with
the head page (where page->flags corresponds to folio->flags) and never
with tail pages.
>
> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Thanks for all the review!
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 24+ messages in thread* Re: [PATCH v2 10/10] s390/hugetlb: convert PG_arch_1 code to work on folio->flags
2024-05-08 18:08 ` David Hildenbrand
@ 2024-05-10 8:45 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-10 8:45 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Heiko Carstens, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Wed, 8 May 2024 20:08:07 +0200
David Hildenbrand <david@redhat.com> wrote:
> On 07.05.24 18:33, Claudio Imbrenda wrote:
> > On Fri, 12 Apr 2024 16:21:20 +0200
> > David Hildenbrand <david@redhat.com> wrote:
> >
> >> Let's make it clearer that we are always working on folio flags and
> >> never page flags of tail pages.
> >
> > please be a little more verbose, and explain what you are doing (i.e.
> > converting usages of page flags to folio flags), not just why.
> >
> >>
> >> Signed-off-by: David Hildenbrand <david@redhat.com>
> >
> > with a few extra words in the description:
>
> Let's make it clearer that we are always working on folio flags and
> never page flags of tail pages by converting remaining PG_arch_1 users
> that modify page->flags to modify folio->flags instead.
>
> No functional change intended, because we would always have worked with
> the head page (where page->flags corresponds to folio->flags) and never
> with tail pages.
this works, thanks!
>
>
> >
> > Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
>
> Thanks for all the review!
>
^ permalink raw reply [flat|nested] 24+ messages in thread
* Re: [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb
2024-04-12 14:21 [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
` (9 preceding siblings ...)
2024-04-12 14:21 ` [PATCH v2 10/10] s390/hugetlb: convert PG_arch_1 code to work on folio->flags David Hildenbrand
@ 2024-04-30 18:49 ` David Hildenbrand
2024-05-06 8:38 ` Heiko Carstens
10 siblings, 1 reply; 24+ messages in thread
From: David Hildenbrand @ 2024-04-30 18:49 UTC (permalink / raw)
To: linux-kernel
Cc: kvm, linux-s390, Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Janosch Frank,
Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On 12.04.24 16:21, David Hildenbrand wrote:
> This is v2 of [1] with changed subject:
> "[PATCH v1 0/5] s390: page_mapcount(), page_has_private() and PG_arch_1"
>
> Rebased on s390x/features which contains the page_mapcount() and
> page_has_private() cleanups, and some PG_arch_1 cleanups from Willy. To
> compensate, I added some more cleanups ;)
>
> One "easy" fix upfront. Another issue I spotted is documented in [1].
>
> Once this hits upstream, we can remove HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
> from core-mm and s390x, so only the folio variant will remain.
Ping.
--
Cheers,
David / dhildenb
^ permalink raw reply [flat|nested] 24+ messages in thread* Re: [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb
2024-04-30 18:49 ` [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb David Hildenbrand
@ 2024-05-06 8:38 ` Heiko Carstens
2024-05-07 16:34 ` Claudio Imbrenda
0 siblings, 1 reply; 24+ messages in thread
From: Heiko Carstens @ 2024-05-06 8:38 UTC (permalink / raw)
To: David Hildenbrand
Cc: linux-kernel, kvm, linux-s390, Vasily Gorbik, Alexander Gordeev,
Christian Borntraeger, Sven Schnelle, Janosch Frank,
Claudio Imbrenda, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Tue, Apr 30, 2024 at 08:49:31PM +0200, David Hildenbrand wrote:
> On 12.04.24 16:21, David Hildenbrand wrote:
> > This is v2 of [1] with changed subject:
> > "[PATCH v1 0/5] s390: page_mapcount(), page_has_private() and PG_arch_1"
> >
> > Rebased on s390x/features which contains the page_mapcount() and
> > page_has_private() cleanups, and some PG_arch_1 cleanups from Willy. To
> > compensate, I added some more cleanups ;)
> >
> > One "easy" fix upfront. Another issue I spotted is documented in [1].
> >
> > Once this hits upstream, we can remove HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
> > from core-mm and s390x, so only the folio variant will remain.
>
> Ping.
Claudio, Janosch, this series requires your review.
^ permalink raw reply [flat|nested] 24+ messages in thread
* Re: [PATCH v2 00/10] s390: PG_arch_1+folio cleanups for uv+hugetlb
2024-05-06 8:38 ` Heiko Carstens
@ 2024-05-07 16:34 ` Claudio Imbrenda
0 siblings, 0 replies; 24+ messages in thread
From: Claudio Imbrenda @ 2024-05-07 16:34 UTC (permalink / raw)
To: Heiko Carstens
Cc: David Hildenbrand, linux-kernel, kvm, linux-s390, Vasily Gorbik,
Alexander Gordeev, Christian Borntraeger, Sven Schnelle,
Janosch Frank, Gerald Schaefer, Matthew Wilcox, Thomas Huth
On Mon, 6 May 2024 10:38:30 +0200
Heiko Carstens <hca@linux.ibm.com> wrote:
> On Tue, Apr 30, 2024 at 08:49:31PM +0200, David Hildenbrand wrote:
> > On 12.04.24 16:21, David Hildenbrand wrote:
> > > This is v2 of [1] with changed subject:
> > > "[PATCH v1 0/5] s390: page_mapcount(), page_has_private() and PG_arch_1"
> > >
> > > Rebased on s390x/features which contains the page_mapcount() and
> > > page_has_private() cleanups, and some PG_arch_1 cleanups from Willy. To
> > > compensate, I added some more cleanups ;)
> > >
> > > One "easy" fix upfront. Another issue I spotted is documented in [1].
> > >
> > > Once this hits upstream, we can remove HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
> > > from core-mm and s390x, so only the folio variant will remain.
> >
> > Ping.
>
> Claudio, Janosch, this series requires your review.
oops! I had started reviewing it, but then other things got in the
way...
^ permalink raw reply [flat|nested] 24+ messages in thread