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authorJames Hogan <james.hogan@imgtec.com>2017-03-14 13:15:20 +0300
committerJames Hogan <james.hogan@imgtec.com>2017-03-28 16:53:47 +0300
commit578fd61d2d210a3b58dc107f5382b965922ac253 (patch)
tree57b7002cc0f04c8586e8820791f74dc86dc73b8c /Documentation/virtual
parenta8a3c426772e55ae9c3209f061cb6317268f932c (diff)
downloadlinux-578fd61d2d210a3b58dc107f5382b965922ac253.tar.xz
KVM: MIPS: Add 64BIT capability
Add a new KVM_CAP_MIPS_64BIT capability to indicate that 64-bit MIPS guests are available and supported. In this case it should still be possible to run 32-bit guest code. If not available it won't be possible to run 64-bit guest code and the instructions may not be available, or the kernel may not support full context switching of 64-bit registers. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> 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/api.txt25
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 4b5fa2571efa..1b8486c094b4 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -4192,3 +4192,28 @@ to KVM_CREATE_VM to create a VM which utilises it.
If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is
available, it means that the VM is using trap & emulate.
+
+8.7 KVM_CAP_MIPS_64BIT
+
+Architectures: mips
+
+This capability indicates the supported architecture type of the guest, i.e. the
+supported register and address width.
+
+The values returned when this capability is checked by KVM_CHECK_EXTENSION on a
+kvm VM handle correspond roughly to the CP0_Config.AT register field, and should
+be checked specifically against known values (see below). All other values are
+reserved.
+
+ 0: MIPS32 or microMIPS32.
+ Both registers and addresses are 32-bits wide.
+ It will only be possible to run 32-bit guest code.
+
+ 1: MIPS64 or microMIPS64 with access only to 32-bit compatibility segments.
+ Registers are 64-bits wide, but addresses are 32-bits wide.
+ 64-bit guest code may run but cannot access MIPS64 memory segments.
+ It will also be possible to run 32-bit guest code.
+
+ 2: MIPS64 or microMIPS64 with access to all address segments.
+ Both registers and addresses are 64-bits wide.
+ It will be possible to run 64-bit or 32-bit guest code.