docs: kvm: Convert s390-diag.txt to ReST format

This file is almost in ReST format. Just one change was
needed:

    - Add markups for a literal block and change its indentation.

While here, use the standard markup for the document title.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/Documentation/virt/kvm/index.rst b/Documentation/virt/kvm/index.rst
index d0e17e71746124586eedc1417a479dfe9d68e2be..e5ea75f97d524f4e915d19fbe7a6e065825c86a5 100644 (file)
--- a/Documentation/virt/kvm/index.rst
+++ b/Documentation/virt/kvm/index.rst
@@ -17,6 +17,7 @@ KVM
    msr
    nested-vmx
    ppc-pv
+   s390-diag
    vcpu-requests
 
    arm/index

diff --git a/Documentation/virt/kvm/s390-diag.rst b/Documentation/virt/kvm/s390-diag.rst
new file mode 100644 (file)
index 0000000..eaac486
--- /dev/null
+++ b/Documentation/virt/kvm/s390-diag.rst
@@ -0,0 +1,86 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=============================
+The s390 DIAGNOSE call on KVM
+=============================
+
+KVM on s390 supports the DIAGNOSE call for making hypercalls, both for
+native hypercalls and for selected hypercalls found on other s390
+hypervisors.
+
+Note that bits are numbered as by the usual s390 convention (most significant
+bit on the left).
+
+
+General remarks
+---------------
+
+DIAGNOSE calls by the guest cause a mandatory intercept. This implies
+all supported DIAGNOSE calls need to be handled by either KVM or its
+userspace.
+
+All DIAGNOSE calls supported by KVM use the RS-a format::
+
+  --------------------------------------
+  |  '83'  | R1 | R3 | B2 |     D2     |
+  --------------------------------------
+  0        8    12   16   20           31
+
+The second-operand address (obtained by the base/displacement calculation)
+is not used to address data. Instead, bits 48-63 of this address specify
+the function code, and bits 0-47 are ignored.
+
+The supported DIAGNOSE function codes vary by the userspace used. For
+DIAGNOSE function codes not specific to KVM, please refer to the
+documentation for the s390 hypervisors defining them.
+
+
+DIAGNOSE function code 'X'500' - KVM virtio functions
+-----------------------------------------------------
+
+If the function code specifies 0x500, various virtio-related functions
+are performed.
+
+General register 1 contains the virtio subfunction code. Supported
+virtio subfunctions depend on KVM's userspace. Generally, userspace
+provides either s390-virtio (subcodes 0-2) or virtio-ccw (subcode 3).
+
+Upon completion of the DIAGNOSE instruction, general register 2 contains
+the function's return code, which is either a return code or a subcode
+specific value.
+
+Subcode 0 - s390-virtio notification and early console printk
+    Handled by userspace.
+
+Subcode 1 - s390-virtio reset
+    Handled by userspace.
+
+Subcode 2 - s390-virtio set status
+    Handled by userspace.
+
+Subcode 3 - virtio-ccw notification
+    Handled by either userspace or KVM (ioeventfd case).
+
+    General register 2 contains a subchannel-identification word denoting
+    the subchannel of the virtio-ccw proxy device to be notified.
+
+    General register 3 contains the number of the virtqueue to be notified.
+
+    General register 4 contains a 64bit identifier for KVM usage (the
+    kvm_io_bus cookie). If general register 4 does not contain a valid
+    identifier, it is ignored.
+
+    After completion of the DIAGNOSE call, general register 2 may contain
+    a 64bit identifier (in the kvm_io_bus cookie case), or a negative
+    error value, if an internal error occurred.
+
+    See also the virtio standard for a discussion of this hypercall.
+
+
+DIAGNOSE function code 'X'501 - KVM breakpoint
+----------------------------------------------
+
+If the function code specifies 0x501, breakpoint functions may be performed.
+This function code is handled by userspace.
+
+This diagnose function code has no subfunctions and uses no parameters.

diff --git a/Documentation/virt/kvm/s390-diag.txt b/Documentation/virt/kvm/s390-diag.txt
deleted file mode 100644 (file)
index 7c52e5f..0000000
--- a/Documentation/virt/kvm/s390-diag.txt
+++ /dev/null
@@ -1,83 +0,0 @@
-The s390 DIAGNOSE call on KVM
-=============================
-
-KVM on s390 supports the DIAGNOSE call for making hypercalls, both for
-native hypercalls and for selected hypercalls found on other s390
-hypervisors.
-
-Note that bits are numbered as by the usual s390 convention (most significant
-bit on the left).
-
-
-General remarks
----------------
-
-DIAGNOSE calls by the guest cause a mandatory intercept. This implies
-all supported DIAGNOSE calls need to be handled by either KVM or its
-userspace.
-
-All DIAGNOSE calls supported by KVM use the RS-a format:
-
---------------------------------------
-|  '83'  | R1 | R3 | B2 |     D2     |
---------------------------------------
-0        8    12   16   20           31
-
-The second-operand address (obtained by the base/displacement calculation)
-is not used to address data. Instead, bits 48-63 of this address specify
-the function code, and bits 0-47 are ignored.
-
-The supported DIAGNOSE function codes vary by the userspace used. For
-DIAGNOSE function codes not specific to KVM, please refer to the
-documentation for the s390 hypervisors defining them.
-
-
-DIAGNOSE function code 'X'500' - KVM virtio functions
------------------------------------------------------
-
-If the function code specifies 0x500, various virtio-related functions
-are performed.
-
-General register 1 contains the virtio subfunction code. Supported
-virtio subfunctions depend on KVM's userspace. Generally, userspace
-provides either s390-virtio (subcodes 0-2) or virtio-ccw (subcode 3).
-
-Upon completion of the DIAGNOSE instruction, general register 2 contains
-the function's return code, which is either a return code or a subcode
-specific value.
-
-Subcode 0 - s390-virtio notification and early console printk
-    Handled by userspace.
-
-Subcode 1 - s390-virtio reset
-    Handled by userspace.
-
-Subcode 2 - s390-virtio set status
-    Handled by userspace.
-
-Subcode 3 - virtio-ccw notification
-    Handled by either userspace or KVM (ioeventfd case).
-
-    General register 2 contains a subchannel-identification word denoting
-    the subchannel of the virtio-ccw proxy device to be notified.
-
-    General register 3 contains the number of the virtqueue to be notified.
-
-    General register 4 contains a 64bit identifier for KVM usage (the
-    kvm_io_bus cookie). If general register 4 does not contain a valid
-    identifier, it is ignored.
-
-    After completion of the DIAGNOSE call, general register 2 may contain
-    a 64bit identifier (in the kvm_io_bus cookie case), or a negative
-    error value, if an internal error occurred.
-
-    See also the virtio standard for a discussion of this hypercall.
-
-
-DIAGNOSE function code 'X'501 - KVM breakpoint
-----------------------------------------------
-
-If the function code specifies 0x501, breakpoint functions may be performed.
-This function code is handled by userspace.
-
-This diagnose function code has no subfunctions and uses no parameters.