So far we've been restricting ourselves to r0-r29 as registers an mtmsr
instruction could use. This was bad, as there are some code paths in
Linux actually using r30.
So let's instead handle all registers gracefully and get rid of that
stupid limitation
Signed-off-by: Alexander Graf <agraf@suse.de>
This is the guest side of the mtsr acceleration. Using this a guest can now
call mtsrin with almost no overhead as long as it ensures that it only uses
it with (MSR_IR|MSR_DR) == 0. Linux does that, so we're good.
Signed-off-by: Alexander Graf <agraf@suse.de>
We will soon add SR PV support to the shared page, so we need some
infrastructure that allows the guest to query for features KVM exports.
This patch adds a second return value to the magic mapping that
indicated to the guest which features are available.
Signed-off-by: Alexander Graf <agraf@suse.de>
When CONFIG_KVM_GUEST is selected, but CONFIG_KVM is not, we were missing
some defines in asm-offsets.c and included too many headers at other places.
This patch makes above configuration work.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
On BookE the preferred way to write the EE bit is the wrteei instruction. It
already encodes the EE bit in the instruction.
So in order to get BookE some speedups as well, let's also PV'nize thati
instruction.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
There is also a form of mtmsr where all bits need to be addressed. While the
PPC64 Linux kernel behaves resonably well here, on PPC32 we do not have an
L=1 form. It does mtmsr even for simple things like only changing EE.
So we need to hook into that one as well and check for a mask of bits that we
deem safe to change from within guest context.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The PowerPC ISA has a special instruction for mtmsr that only changes the EE
and RI bits, namely the L=1 form.
Since that one is reasonably often occuring and simple to implement, let's
go with this first. Writing EE=0 is always just a store. Doing EE=1 also
requires us to check for pending interrupts and if necessary exit back to the
hypervisor.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We will need to patch several instruction streams over to a different
code path, so we need a way to patch a single instruction with a branch
somewhere else.
This patch adds a helper to facilitate this patching.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We will soon require more sophisticated methods to replace single instructions
with multiple instructions. We do that by branching to a memory region where we
write replacement code for the instruction to.
This region needs to be within 32 MB of the patched instruction though, because
that's the furthest we can jump with immediate branches.
So we keep 1MB of free space around in bss. After we're done initing we can just
tell the mm system that the unused pages are free, but until then we have enough
space to fit all our code in.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
With our current MMU scheme we don't need to know about the tlbsync instruction.
So we can just nop it out.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Some instructions can simply be replaced by load and store instructions to
or from the magic page.
This patch replaces often called instructions that fall into the above category.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We will soon start and replace instructions from the text section with
other, paravirtualized versions. To ease the readability of those patches
I split out the generic looping and magic page mapping code out.
This patch still only contains stubs. But at least it loops through the
text section :).
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We have all the hypervisor pieces in place now, but the guest parts are still
missing.
This patch implements basic awareness of KVM when running Linux as guest. It
doesn't do anything with it yet though.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
To communicate with KVM directly we need to plumb some sort of interface
between the guest and KVM. Usually those interfaces use hypercalls.
This hypercall implementation is described in the last patch of the series
in a special documentation file. Please read that for further information.
This patch implements stubs to handle KVM PPC hypercalls on the host and
guest side alike.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Alexander Graf