KVM: PPC: booke: category E.HV (GS-mode) support

Chips such as e500mc that implement category E.HV in Power ISA 2.06
provide hardware virtualization features, including a new MSR mode for
guest state.  The guest OS can perform many operations without trapping
into the hypervisor, including transitions to and from guest userspace.

Since we can use SRR1[GS] to reliably tell whether an exception came from
guest state, instead of messing around with IVPR, we use DO_KVM similarly
to book3s.

Current issues include:
 - Machine checks from guest state are not routed to the host handler.
 - The guest can cause a host oops by executing an emulated instruction
   in a page that lacks read permission.  Existing e500/4xx support has
   the same problem.

Includes work by Ashish Kalra <Ashish.Kalra@freescale.com>,
Varun Sethi <Varun.Sethi@freescale.com>, and
Liu Yu <yu.liu@freescale.com>.

Signed-off-by: Scott Wood <scottwood@freescale.com>
[agraf: remove pt_regs usage]
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index 8f64709ae331..2c33cd336434 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -90,6 +90,9 @@ config KVM_BOOK3S_64_PR
         depends on KVM_BOOK3S_64 && !KVM_BOOK3S_64_HV
         select KVM_BOOK3S_PR
 
+config KVM_BOOKE_HV
+        bool
+
 config KVM_440
         bool "KVM support for PowerPC 440 processors"
         depends on EXPERIMENTAL && 44x