summaryrefslogtreecommitdiff
path: root/Documentation/arch/s390
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/arch/s390')
-rw-r--r--Documentation/arch/s390/index.rst1
-rw-r--r--Documentation/arch/s390/mm.rst111
-rw-r--r--Documentation/arch/s390/vfio-ap.rst32
3 files changed, 143 insertions, 1 deletions
diff --git a/Documentation/arch/s390/index.rst b/Documentation/arch/s390/index.rst
index 73c79bf586fd..e75a6e5d2505 100644
--- a/Documentation/arch/s390/index.rst
+++ b/Documentation/arch/s390/index.rst
@@ -8,6 +8,7 @@ s390 Architecture
cds
3270
driver-model
+ mm
monreader
qeth
s390dbf
diff --git a/Documentation/arch/s390/mm.rst b/Documentation/arch/s390/mm.rst
new file mode 100644
index 000000000000..084adad5eef9
--- /dev/null
+++ b/Documentation/arch/s390/mm.rst
@@ -0,0 +1,111 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+Memory Management
+=================
+
+Virtual memory layout
+=====================
+
+.. note::
+
+ - Some aspects of the virtual memory layout setup are not
+ clarified (number of page levels, alignment, DMA memory).
+
+ - Unused gaps in the virtual memory layout could be present
+ or not - depending on how partucular system is configured.
+ No page tables are created for the unused gaps.
+
+ - The virtual memory regions are tracked or untracked by KASAN
+ instrumentation, as well as the KASAN shadow memory itself is
+ created only when CONFIG_KASAN configuration option is enabled.
+
+::
+
+ =============================================================================
+ | Physical | Virtual | VM area description
+ =============================================================================
+ +- 0 --------------+- 0 --------------+
+ | | S390_lowcore | Low-address memory
+ | +- 8 KB -----------+
+ | | |
+ | | |
+ | | ... unused gap | KASAN untracked
+ | | |
+ +- AMODE31_START --+- AMODE31_START --+ .amode31 rand. phys/virt start
+ |.amode31 text/data|.amode31 text/data| KASAN untracked
+ +- AMODE31_END ----+- AMODE31_END ----+ .amode31 rand. phys/virt end (<2GB)
+ | | |
+ | | |
+ +- __kaslr_offset_phys | kernel rand. phys start
+ | | |
+ | kernel text/data | |
+ | | |
+ +------------------+ | kernel phys end
+ | | |
+ | | |
+ | | |
+ | | |
+ +- ident_map_size -+ |
+ | |
+ | ... unused gap | KASAN untracked
+ | |
+ +- __identity_base + identity mapping start (>= 2GB)
+ | |
+ | identity | phys == virt - __identity_base
+ | mapping | virt == phys + __identity_base
+ | |
+ | | KASAN tracked
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ | |
+ +---- vmemmap -----+ 'struct page' array start
+ | |
+ | virtually mapped |
+ | memory map | KASAN untracked
+ | |
+ +- __abs_lowcore --+
+ | |
+ | Absolute Lowcore | KASAN untracked
+ | |
+ +- __memcpy_real_area
+ | |
+ | Real Memory Copy| KASAN untracked
+ | |
+ +- VMALLOC_START --+ vmalloc area start
+ | | KASAN untracked or
+ | vmalloc area | KASAN shallowly populated in case
+ | | CONFIG_KASAN_VMALLOC=y
+ +- MODULES_VADDR --+ modules area start
+ | | KASAN allocated per module or
+ | modules area | KASAN shallowly populated in case
+ | | CONFIG_KASAN_VMALLOC=y
+ +- __kaslr_offset -+ kernel rand. virt start
+ | | KASAN tracked
+ | kernel text/data | phys == (kvirt - __kaslr_offset) +
+ | | __kaslr_offset_phys
+ +- kernel .bss end + kernel rand. virt end
+ | |
+ | ... unused gap | KASAN untracked
+ | |
+ +------------------+ UltraVisor Secure Storage limit
+ | |
+ | ... unused gap | KASAN untracked
+ | |
+ +KASAN_SHADOW_START+ KASAN shadow memory start
+ | |
+ | KASAN shadow | KASAN untracked
+ | |
+ +------------------+ ASCE limit
diff --git a/Documentation/arch/s390/vfio-ap.rst b/Documentation/arch/s390/vfio-ap.rst
index 929ee1c1c940..ea744cbc8687 100644
--- a/Documentation/arch/s390/vfio-ap.rst
+++ b/Documentation/arch/s390/vfio-ap.rst
@@ -380,6 +380,36 @@ matrix device.
control_domains:
A read-only file for displaying the control domain numbers assigned to the
vfio_ap mediated device.
+ ap_config:
+ A read/write file that, when written to, allows all three of the
+ vfio_ap mediated device's ap matrix masks to be replaced in one shot.
+ Three masks are given, one for adapters, one for domains, and one for
+ control domains. If the given state cannot be set then no changes are
+ made to the vfio-ap mediated device.
+
+ The format of the data written to ap_config is as follows:
+ {amask},{dmask},{cmask}\n
+
+ \n is a newline character.
+
+ amask, dmask, and cmask are masks identifying which adapters, domains,
+ and control domains should be assigned to the mediated device.
+
+ The format of a mask is as follows:
+ 0xNN..NN
+
+ Where NN..NN is 64 hexadecimal characters representing a 256-bit value.
+ The leftmost (highest order) bit represents adapter/domain 0.
+
+ For an example set of masks that represent your mdev's current
+ configuration, simply cat ap_config.
+
+ Setting an adapter or domain number greater than the maximum allowed for
+ the system will result in an error.
+
+ This attribute is intended to be used by automation. End users would be
+ better served using the respective assign/unassign attributes for
+ adapters, domains, and control domains.
* functions:
@@ -550,7 +580,7 @@ These are the steps:
following Kconfig elements selected:
* IOMMU_SUPPORT
* S390
- * ZCRYPT
+ * AP
* VFIO
* KVM