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authorJanosch Frank <frankja@linux.ibm.com>2020-09-07 15:46:59 +0300
committerVasily Gorbik <gor@linux.ibm.com>2020-09-14 12:38:35 +0300
commit1a80b54d1ce1556bba6a8d8cd9384d6a9dcb641a (patch)
treefdbda1789a1e4338480d69a040182a83d8764b42 /arch/s390/kernel/uv.c
parente670e64af1d46571be3d9b1177024d9c8520087c (diff)
downloadlinux-1a80b54d1ce1556bba6a8d8cd9384d6a9dcb641a.tar.xz
s390/uv: add destroy page call
We don't need to export pages if we destroy the VM configuration afterwards anyway. Instead we can destroy the page which will zero it and then make it accessible to the host. Destroying is about twice as fast as the export. Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/kvm/20200907124700.10374-2-frankja@linux.ibm.com/ Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/uv.c')
-rw-r--r--arch/s390/kernel/uv.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index c296e5c8dbf9..d3399b8a9b23 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -119,6 +119,26 @@ static int uv_pin_shared(unsigned long paddr)
}
/*
+ * Requests the Ultravisor to destroy a guest page and make it
+ * accessible to the host. The destroy clears the page instead of
+ * exporting.
+ *
+ * @paddr: Absolute host address of page to be destroyed
+ */
+int uv_destroy_page(unsigned long paddr)
+{
+ struct uv_cb_cfs uvcb = {
+ .header.cmd = UVC_CMD_DESTR_SEC_STOR,
+ .header.len = sizeof(uvcb),
+ .paddr = paddr
+ };
+
+ if (uv_call(0, (u64)&uvcb))
+ return -EINVAL;
+ return 0;
+}
+
+/*
* Requests the Ultravisor to encrypt a guest page and make it
* accessible to the host for paging (export).
*