When using exit timing stats, we clobber r9 in the NEED_EMU case,
so better move that part down a few lines and fix it that way.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
There's always a chance we're unable to read a guest instruction. The guest
could have its TLB mapped execute-, but not readable, something odd happens
and our TLB gets flushed. So it's a good idea to be prepared for that case
and have a fallback that allows us to fix things up in that case.
Add fixup code that keeps guest code from potentially crashing our host kernel.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
If we hit any exception whatsoever in the restore path and r1/r2 aren't the
host registers, we don't get a working oops. So it's always a good idea to
restore them as early as possible.
This time, it actually has practical reasons to do so too, since we need to
have the host page fault handler fix up our guest instruction read code. And
for that to work we need r1/r2 restored.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
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>