On 06.09.21 17:56, Claudio Imbrenda wrote:
On Mon, 6 Sep 2021 17:46:40 +0200
Christian Borntraeger <borntraeger@xxxxxxxxxx> wrote:
On 18.08.21 15:26, Claudio Imbrenda wrote:
Introduce variants of the convert and destroy page functions that also
clear the PG_arch_1 bit used to mark them as secure pages.
These new functions can only be called on pages for which a reference
is already being held.
Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
Acked-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
Can you refresh my mind? We do have over-indication of PG_arch_1 and this
might result in spending some unneeded cycles but in the end this will be
correct. Right?
And this patch will fix some unnecessary places that add overindication.
correct, PG_arch_1 will still overindicate, but with this patch it will
happen less.
And PG_arch_1 overindication is perfectly fine from a correctness point
of view.
Maybe add something like this to the patch description then.
+/*
+ * The caller must already hold a reference to the page
+ */
+int uv_destroy_owned_page(unsigned long paddr)
+{
+ struct page *page = phys_to_page(paddr);
Do we have to protect against weird mappings without struct page here? I have not
followed the discussion about this topic. Maybe Gerald knows if we can have memory
without struct pages.
+ int rc;
+
+ get_page(page);
+ rc = uv_destroy_page(paddr);
+ if (!rc)
+ clear_bit(PG_arch_1, &page->flags);
+ put_page(page);
+ return rc;
+}
+
/*
* Requests the Ultravisor to encrypt a guest page and make it
* accessible to the host for paging (export).
@@ -154,6 +170,22 @@ int uv_convert_from_secure(unsigned long paddr)
return 0;
}
+/*
+ * The caller must already hold a reference to the page
+ */
+int uv_convert_owned_from_secure(unsigned long paddr)
+{
+ struct page *page = phys_to_page(paddr);
Same here. If this is not an issue (and you add something to the patch description as
outlined above)
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
