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authorMauro Carvalho Chehab <mchehab+huawei@kernel.org>2020-02-10 07:03:02 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2020-02-12 20:10:05 +0100
commitc849d8613991292d5f945956780bb8134cbce7ed (patch)
treeb565891c1023811a38b97252f3329f2eda771bc6 /Documentation/virt/kvm/ppc-pv.rst
parentdocs: kvm: Convert nested-vmx.txt to ReST format (diff)
downloadlinux-dev-c849d8613991292d5f945956780bb8134cbce7ed.tar.xz
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docs: kvm: Convert ppc-pv.txt to ReST format
- Use document title and chapter markups; - Add markups for tables; - Use list markups; - Add markups for literal blocks; - Add blank lines. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to '')
-rw-r--r--Documentation/virt/kvm/ppc-pv.rst (renamed from Documentation/virt/kvm/ppc-pv.txt)26
1 files changed, 18 insertions, 8 deletions
diff --git a/Documentation/virt/kvm/ppc-pv.txt b/Documentation/virt/kvm/ppc-pv.rst
index e26115ce4258..5fdb907670be 100644
--- a/Documentation/virt/kvm/ppc-pv.txt
+++ b/Documentation/virt/kvm/ppc-pv.rst
@@ -1,3 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================================
The PPC KVM paravirtual interface
=================================
@@ -34,8 +37,9 @@ up the hypercall. To call a hypercall, just call these instructions.
The parameters are as follows:
+ ======== ================ ================
Register IN OUT
-
+ ======== ================ ================
r0 - volatile
r3 1st parameter Return code
r4 2nd parameter 1st output value
@@ -47,6 +51,7 @@ The parameters are as follows:
r10 8th parameter 7th output value
r11 hypercall number 8th output value
r12 - volatile
+ ======== ================ ================
Hypercall definitions are shared in generic code, so the same hypercall numbers
apply for x86 and powerpc alike with the exception that each KVM hypercall
@@ -54,11 +59,13 @@ also needs to be ORed with the KVM vendor code which is (42 << 16).
Return codes can be as follows:
+ ==== =========================
Code Meaning
-
+ ==== =========================
0 Success
12 Hypercall not implemented
<0 Error
+ ==== =========================
The magic page
==============
@@ -72,7 +79,7 @@ desired location. The first parameter indicates the effective address when the
MMU is enabled. The second parameter indicates the address in real mode, if
applicable to the target. For now, we always map the page to -4096. This way we
can access it using absolute load and store functions. The following
-instruction reads the first field of the magic page:
+instruction reads the first field of the magic page::
ld rX, -4096(0)
@@ -93,8 +100,10 @@ a bitmap of available features inside the magic page.
The following enhancements to the magic page are currently available:
+ ============================ =======================================
KVM_MAGIC_FEAT_SR Maps SR registers r/w in the magic page
KVM_MAGIC_FEAT_MAS0_TO_SPRG7 Maps MASn, ESR, PIR and high SPRGs
+ ============================ =======================================
For enhanced features in the magic page, please check for the existence of the
feature before using them!
@@ -121,8 +130,8 @@ when entering the guest or don't have any impact on the hypervisor's behavior.
The following bits are safe to be set inside the guest:
- MSR_EE
- MSR_RI
+ - MSR_EE
+ - MSR_RI
If any other bit changes in the MSR, please still use mtmsr(d).
@@ -138,9 +147,9 @@ guest. Implementing any of those mappings is optional, as the instruction traps
also act on the shared page. So calling privileged instructions still works as
before.
+======================= ================================
From To
-==== ==
-
+======================= ================================
mfmsr rX ld rX, magic_page->msr
mfsprg rX, 0 ld rX, magic_page->sprg0
mfsprg rX, 1 ld rX, magic_page->sprg1
@@ -173,7 +182,7 @@ mtsrin rX, rY b <special mtsrin section>
[BookE only]
wrteei [0|1] b <special wrteei section>
-
+======================= ================================
Some instructions require more logic to determine what's going on than a load
or store instruction can deliver. To enable patching of those, we keep some
@@ -191,6 +200,7 @@ for example.
Hypercall ABIs in KVM on PowerPC
=================================
+
1) KVM hypercalls (ePAPR)
These are ePAPR compliant hypercall implementation (mentioned above). Even