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authorJames Hogan <james.hogan@imgtec.com>2017-03-14 10:15:14 +0000
committerJames Hogan <james.hogan@imgtec.com>2017-03-28 14:53:33 +0100
commit955d8dc3ee555e9320fabbeab0969f9cf7660f9d (patch)
treeb6a2787a9b99078a7387c90a2f8ddaee63840830 /Documentation/virtual
parenta6c09b9f9d1c3b1daf8e24e5556d73b9303843ef (diff)
KVM: MIPS: Implement HYPCALL emulation
Emulate the HYPCALL instruction added in the VZ ASE and used by the MIPS paravirtualised guest support that is already merged. The new hypcall.c handles arguments and the return value. No actual hypercalls are yet supported, but this still allows us to safely step over hypercalls and set an error code in the return value for forward compatibility. Non-zero HYPCALL codes are not handled. We also document the hypercall ABI which asm/kvm_para.h uses. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com> Cc: David Daney <david.daney@cavium.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Cc: linux-doc@vger.kernel.org
Diffstat (limited to 'Documentation/virtual')
-rw-r--r--Documentation/virtual/kvm/hypercalls.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/hypercalls.txt b/Documentation/virtual/kvm/hypercalls.txt
index feaaa634f154..a890529c63ed 100644
--- a/Documentation/virtual/kvm/hypercalls.txt
+++ b/Documentation/virtual/kvm/hypercalls.txt
@@ -28,6 +28,11 @@ S390:
property inside the device tree's /hypervisor node.
For more information refer to Documentation/virtual/kvm/ppc-pv.txt
+MIPS:
+ KVM hypercalls use the HYPCALL instruction with code 0 and the hypercall
+ number in $2 (v0). Up to four arguments may be placed in $4-$7 (a0-a3) and
+ the return value is placed in $2 (v0).
+
KVM Hypercalls Documentation
===========================
The template for each hypercall is: