Mac OS X uses the dcba instruction. According to the specification it doesn't
guarantee any functionality, so let's just emulate it as nop.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
On most systems we need to emulate dcbz when running 32 bit guests. So
far we've been rather slack, not giving correct DSISR values to the guest.
This patch makes the emulation more accurate, introducing a difference
between "page not mapped" and "write protection fault". While at it, it
also speeds up dcbz emulation by an order of magnitude by using kmap.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The FPU/Altivec/VSX enablement also brought access to some structure
elements that are only defined when the respective config options
are enabled.
Unfortuately I forgot to check for the config options at some places,
so let's do that now.
Unbreaks the build when CONFIG_VSX is not set.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
MOL uses its own hypercall interface to call back into userspace when
the guest wants to do something.
So let's implement that as an exit reason, specify it with a CAP and
only really use it when userspace wants us to.
The only user of it so far is MOL.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Some times we don't want all capabilities to be available to all
our vcpus. One example for that is the OSI interface, implemented
in the next patch.
In order to have a generic mechanism in how to enable capabilities
individually, this patch introduces a new ioctl that can be used
for this purpose. That way features we don't want in all guests or
userspace configurations can just not be enabled and we're good.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Mac OS X has some applications - namely the Finder - that require alignment
interrupts to work properly. So we need to implement them.
But the spec for 970 and 750 also looks different. While 750 requires the
DSISR and DAR fields to reflect some instruction bits (DSISR) and the fault
address (DAR), the 970 declares this as an optional feature. So we need
to reconstruct DSISR and DAR manually.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We get MMIOs with the weirdest instructions. But every time we do,
we need to improve our emulator to implement them.
So let's do that - this time it's lbzux and lhax's round.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We have a 32 bit value in the PACA to store XER in. We also do an stw
when storing XER in there. But then we load it with ld, completely
screwing it up on every entry.
Welcome to the Big Endian world.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
BATs can't only be written to, you can also read them out!
So let's implement emulation for reading BAT values again.
While at it, I also made BAT setting flush the segment cache,
so we're absolutely sure there's no MMU state left when writing
BATs.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We emulate the mfsrin instruction already, that passes the SR number
in a register value. But we lacked support for mfsr that encoded the
SR number in the opcode.
So let's implement it.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When trying to read or store vcpu register data, we should also make
sure the vcpu is actually loaded, so we're 100% sure we get the correct
values.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When the guest activates the FPU, we load it up. That's fine when
it wasn't activated before on the host, but if it was we end up
reloading FPU values from last time the FPU was deactivated on the
host without writing the proper values back to the vcpu struct.
This patch checks if the FPU is enabled already and if so just doesn't
bother activating it, making FPU operations survive guest context switches.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The current check_ext function reads the instruction and then does
the checking. Let's split the reading out so we can reuse it for
different functions.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
This patch makes the VSID of mapped pages always reflecting all special cases
we have, like split mode.
It also changes the tlbie mask to 0x0ffff000 according to the spec. The mask
we used before was incorrect.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
DSISR is only defined as 32 bits wide. So let's reflect that in the
structs too.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Userspace can tell us that it wants to trigger an interrupt. But
so far it can't tell us that it wants to stop triggering one.
So let's interpret the parameter to the ioctl that we have anyways
to tell us if we want to raise or lower the interrupt line.
Signed-off-by: Alexander Graf <agraf@suse.de>
v2 -> v3:
- Add CAP for unset irq
Signed-off-by: Avi Kivity <avi@redhat.com>
On PowerPC we can go into MMU Split Mode. That means that either
data relocation is on but instruction relocation is off or vice
versa.
That mode didn't work properly, as we weren't always flushing
entries when going into a new split mode, potentially mapping
different code or data that we're supposed to.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
If fail to create the vcpu, we should not create the debugfs
for it.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Acked-by: Alexander Graf <agraf@suse.de>
Cc: stable@kernel.org
Signed-off-by: Avi Kivity <avi@redhat.com>
An index of KVM44x_GUEST_TLB_SIZE is already one too large.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Hollis Blanchard <hollis@penguinppc.org>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When we destory a vcpu, we should also make sure to kill all pending
timers that could still be up. When not doing this, hrtimers might
dereference null pointers trying to call our code.
This patch fixes spontanious kernel panics seen after closing VMs.
Signed-off-by: Alexander Graf <alex@csgraf.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
While converting the kzalloc we used to allocate our vcpu struct to
vmalloc, I forgot to memset the contents to zeros. That broke quite
a lot.
This patch memsets it to zero again.
Signed-off-by: Alexander Graf <alex@csgraf.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We used to use get_free_pages to allocate our vcpu struct. Unfortunately
that call failed on me several times after my machine had a big enough
uptime, as memory became too fragmented by then.
Fortunately, we don't need it to be page aligned any more! We can just
vmalloc it and everything's great.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We don't need as complex code. I had some thinkos while writing it, figuring
I needed to support PPC32 paths on PPC64 which would have required DR=0, but
everything just runs fine with DR=1.
So let's make the functions simple C call wrappers that reserve some space on
the stack for the respective functions to clobber.
Fixes out-of-RMA-access (and thus guest FPU loading) on the PS3.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We had code to make use of the secondary htab buckets, but kept that
disabled because it was unstable when I put it in.
I checked again if that's still the case and apparently it was only
exposing some instability that was there anyways before. I haven't
seen any badness related to usage of secondary htab entries so far.
This should speed up guest memory allocations by quite a bit, because
we now have more space to put PTEs in.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We need to tell userspace that we can emulate paired single instructions.
So let's add a capability export.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The one big thing about the Gekko is paired singles.
Paired singles are an extension to the instruction set, that adds 32 single
precision floating point registers (qprs), some SPRs to modify the behavior
of paired singled operations and instructions to deal with qprs to the
instruction set.
Unfortunately, it also changes semantics of existing operations that affect
single values in FPRs. In most cases they get mirrored to the coresponding
QPR.
Thanks to that we need to emulate all FPU operations and all the new paired
single operations too.
In order to achieve that, we use the just introduced FPU call helpers to
call the real FPU whenever the guest wants to modify an FPR. Additionally
we also fix up the QPR values along the way.
That way we can execute paired single FPU operations without implementing a
soft fpu.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When we get a program interrupt we usually don't expect it to perform an
MMIO operation. But why not? When we emulate paired singles, we can end
up loading or storing to an MMIO address - and the handling of those
happens in the program interrupt handler.
So let's teach the program interrupt handler how to deal with EMULATE_MMIO.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
BATs didn't work. Well, they did, but only up to BAT3. As soon as we
came to BAT4 the offset calculation was screwed up and we ended up
overwriting BAT0-3.
Fortunately, Linux hasn't been using BAT4+. It's still a good
idea to write correct code though.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
To emulate paired single instructions, we need to be able to call FPU
operations from within the kernel. Since we don't want gcc to spill
arbitrary FPU code everywhere, we tell it to use a soft fpu.
Since we know we can really call the FPU in safe areas, let's also add
some calls that we can later use to actually execute real world FPU
operations on the host's FPU.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We need to call the ext giveup handlers from code outside of book3s.c.
So let's make it non-static.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The Book3S KVM implementation contains some helper functions to load and store
data from and to virtual addresses.
Unfortunately, this helper used to keep the physical address it so nicely
found out for us to itself. So let's change that and make it return the
physical address it resolved.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The Book3S_32 specifications allows for two instructions to modify segment
registers: mtsrin and mtsr.
Most normal operating systems use mtsrin, because it allows to define which
segment it wants to change using a register. But since I was trying to run
an embedded guest, it turned out to be using mtsr with hardcoded values.
So let's also emulate mtsr. It's a valid instruction after all.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
There's a typo in the debug ifdef of the book3s_32 mmu emulation. While trying
to debug something I stumbled across that and wanted to save anyone after me
(or myself later) from having to debug that again.
So let's fix the ifdef.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
There are some situations when we're pretty sure the guest will use the
FPU soon. So we can save the churn of going into the guest, finding out
it does want to use the FPU and going out again.
This patch adds preloading of the FPU when it's reasonable.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When we for example get an Altivec interrupt, but our guest doesn't support
altivec, we need to inject a program interrupt, not an altivec interrupt.
The same goes for paired singles. When an altivec interrupt arrives, we're
pretty sure we need to emulate the instruction because it's a paired single
operation.
So let's make all the ext handlers aware that they need to jump to the
program interrupt handler when an extension interrupt arrives that
was not supposed to arrive for the guest CPU.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The Gekko has some SPR values that differ from other PPC core values and
also some additional ones.
Let's add support for them in our mfspr/mtspr emulator.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The Gekko implements an extension called paired singles. When the guest wants
to use that extension, we need to make sure we're not running the host FPU,
because all FPU instructions need to get emulated to accomodate for additional
operations that occur.
This patch adds an hflag to track if we're in paired single mode or not.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Emulation of an instruction can have different outcomes. It can succeed,
fail, require MMIO, do funky BookE stuff - or it can just realize something's
odd and will be fixed the next time around.
Exactly that is what EMULATE_AGAIN means. Using that flag we can now tell
the caller that nothing happened, but we still want to go back to the
guest and see what happens next time we come around.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The guest I was trying to get to run uses the LHA and LHAU instructions.
Those instructions basically do a load, but also sign extend the result.
Since we need to fill our registers by hand when doing MMIO, we also need
to sign extend manually.
This patch implements sign extended MMIO and the LHA(U) instructions.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Right now MMIO access can only happen for GPRs and is at most 32 bit wide.
That's actually enough for almost all types of hardware out there.
Unfortunately, the guest I was using used FPU writes to MMIO regions, so
it ended up writing 64 bit MMIOs using FPRs and QPRs.
So let's add code to handle those odd cases too.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Int is not long enough to store the size of a dirty bitmap.
This patch fixes this problem with the introduction of a wrapper
function to calculate the sizes of dirty bitmaps.
Note: in mark_page_dirty(), we have to consider the fact that
__set_bit() takes the offset as int, not long.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Old method prematurely sets ESR and DEAR.
Move this part after we decide to inject interrupt,
which is more like hardware behave.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Acked-by: Hollis Blanchard <hollis@penguinppc.org>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
commit 55fb1027c1cf9797dbdeab48180da530e81b1c39 doesn't update tlbcfg correctly.
Fix it.
And since guest OS likes 'fixed' hardware,
initialize tlbcfg everytime when guest access is useless.
So move this part to init code.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
commit 513579e3a3 change the way
we emulate PVR/PIR,
which left PVR/PIR uninitialized on E500, and make guest puzzled.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Latest kernel start to access l1csr0 to contron L1.
We just tell guest no operation is on going.
Signed-off-by: Liu Yu <yu.liu@freescale.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
We keep a copy of the MSR around that we use when we go into the guest context.
That copy is basically the normal process MSR flags OR some allowed guest
specified MSR flags. We also AND the external providers into this, so we get
traps on FPU usage when we haven't activated it on the host yet.
Currently this calculation is part of the set_msr function that we use whenever
we set the guest MSR value. With the external providers, we also have the case
that we don't modify the guest's MSR, but only want to update the shadow MSR.
So let's move the shadow MSR parts to a separate function that we then use
whenever we only need to update it. That way we don't accidently kvm_vcpu_block
within a preempt notifier context.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
SRR1 stores more information that just the MSR value. It also stores
valuable information about the type of interrupt we received, for
example whether the storage interrupt we just got was because of a
missing htab entry or not.
We use that information to speed up the exit path.
Now if we get preempted before we can interpret the shadow_msr values,
we get into vcpu_put which then calls the MSR handler, which then sets
all the SRR1 information bits in shadow_msr to 0. Great.
So let's preserve the SRR1 specific bits in shadow_msr whenever we set
the MSR. They don't hurt.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When our guest starts using either the FPU, Altivec or VSX we need to make
sure Linux knows about it and sneak into its process switching code
accordingly.
This patch makes accesses to the above parts of the system work inside the
VM.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Linux contains quite some bits of code to load FPU, Altivec and VSX lazily for
a task. It calls those bits in real mode, coming from an interrupt handler.
For KVM we better reuse those, so let's wrap a bit of trampoline magic around
them and then we can call them from normal module code.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
An SLB entry contains two pieces of information related to size:
1) PTE size
2) SLB size
The L bit defines the PTE be "large" (usually means 16MB),
SLB_VSID_B_1T defines that the SLB should span 1 GB instead of the
default 256MB.
Apparently I messed things up and just put those two in one box,
shaked it heavily and came up with the current code which handles
large pages incorrectly, because it also treats large page SLB entries
as "1TB" segment entries.
This patch splits those two features apart, making Linux guests boot
even when they have > 256MB.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When we get a program interrupt in guest kernel mode, we try to emulate the
instruction.
If that doesn't fail, we report to the user and try again - at the exact same
instruction pointer. So if the guest kernel really does trigger an invalid
instruction, we loop forever.
So let's better go and forward program exceptions to the guest when we don't
know the instruction we're supposed to emulate.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When we need to reinject a program interrupt into the guest, we also need to
reinject the corresponding flags into the guest.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
The code to unset HID5.dcbz32 is broken.
This patch makes it do the right rotate magic.
Signed-off-by: Alexander Graf <agraf@suse.de>
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
Book3S needs some flags in SRR1 to get to know details about an interrupt.
One such example is the trap instruction. It tells the guest kernel that
a program interrupt is due to a trap using a bit in SRR1.
This patch implements above behavior, making WARN_ON behave like WARN_ON.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently we're racy when doing the transition from IR=1 to IR=0, from
the module memory entry code to the real mode SLB switching code.
To work around that I took a look at the RTAS entry code which is faced
with a similar problem and did the same thing:
A small helper in linear mapped memory that does mtmsr with IR=0 and
then RFIs info the actual handler.
Thanks to that trick we can safely take page faults in the entry code
and only need to be really wary of what to do as of the SLB switching
part.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Using an RFI in IR=1 is dangerous. We need to set two SRRs and then do an RFI
without getting interrupted at all, because every interrupt could potentially
overwrite the SRR values.
Fortunately, we don't need to RFI in at least this particular case of the code,
so we can just replace it with an mtmsr and b.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
To fetch the last instruction we were interrupted on, we enable DR in early
exit code, where we are still in a very transitional phase between guest
and host state.
Most of the time this seemed to work, but another CPU can easily flush our
TLB and HTAB which makes us go in the Linux page fault handler which totally
breaks because we still use the guest's SLB entries.
To work around that, let's introduce a second KVM guest mode that defines
that whenever we get a trap, we don't call the Linux handler or go into
the KVM exit code, but just jump over the faulting instruction.
That way a potentially bad lwz doesn't trigger any faults and we can later
on interpret the invalid instruction we fetched as "fetch didn't work".
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We're being horribly racy right now. All the entry and exit code hijacks
random fields from the PACA that could easily be used by different code in
case we get interrupted, for example by a #MC or even page fault.
After discussing this with Ben, we figured it's best to reserve some more
space in the PACA and just shove off some vcpu state to there.
That way we can drastically improve the readability of the code, make it
less racy and less complex.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
We now have helpers for the GPRs, so let's also add some for CR and XER.
Having them in the PACA simplifies code a lot, as we don't need to care
about where to store CC or not to overflow any integers.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
All code in PPC KVM currently accesses gprs in the vcpu struct directly.
While there's nothing wrong with that wrt the current way gprs are stored
and loaded, it doesn't suffice for the PACA acceleration that will follow
in this patchset.
So let's just create little wrapper inline functions that we call whenever
a GPR needs to be read from or written to. The compiled code shouldn't really
change at all for now.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
The PowerPC C ABI defines that registers r14-r31 need to be preserved across
function calls. Since our exit handler is written in C, we can make use of that
and don't need to reload r14-r31 on every entry/exit cycle.
This technique is also used in the BookE code and is called "lightweight exits"
there. To follow the tradition, it's called the same in Book3S.
So far this optimization was disabled though, as the code didn't do what it was
expected to do, but failed to work.
This patch fixes and enables lightweight exits again.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When we're loading bolted entries into the SLB again, we're checking if an
entry is in use and only slbmte it when it is.
Unfortunately, the check always goes to the skip label of the first entry,
resulting in an endless loop when it actually gets triggered.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Have a pointer to an allocated region inside struct kvm.
[alex: fix ppc book 3s]
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Because we now emulate the DEC interrupt according to real life behavior,
there's no need to keep the AGGRESSIVE_DEC hack around.
Let's just remove it.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Acked-by: Hollis Blanchard <hollis@penguinppc.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
We treated the DEC interrupt like an edge based one. This is not true for
Book3s. The DEC keeps firing until mtdec is issued again and thus clears
the interrupt line.
So let's implement this logic in KVM too. This patch moves the line clearing
from the firing of the interrupt to the mtdec emulation.
This makes PPC64 guests work without AGGRESSIVE_DEC defined.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Acked-by: Hollis Blanchard <hollis@penguinppc.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
We're using a switch table to find the irqprio that belongs to a specific
interrupt vector. This table is part of the interrupt inject logic.
Since we'll add a new function to stop interrupts, let's move this table
out of the injection logic into a separate function.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Acked-by: Hollis Blanchard <hollis@penguinppc.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
Embedded PowerPC KVM has an exit timing implementation to track and evaluate
how much time was spent in which exit path.
For Book3S, we don't implement it. So let's not expose it as a config option
either.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
What it is: vhost net is a character device that can be used to reduce
the number of system calls involved in virtio networking.
Existing virtio net code is used in the guest without modification.
There's similarity with vringfd, with some differences and reduced scope
- uses eventfd for signalling
- structures can be moved around in memory at any time (good for
migration, bug work-arounds in userspace)
- write logging is supported (good for migration)
- support memory table and not just an offset (needed for kvm)
common virtio related code has been put in a separate file vhost.c and
can be made into a separate module if/when more backends appear. I used
Rusty's lguest.c as the source for developing this part : this supplied
me with witty comments I wouldn't be able to write myself.
What it is not: vhost net is not a bus, and not a generic new system
call. No assumptions are made on how guest performs hypercalls.
Userspace hypervisors are supported as well as kvm.
How it works: Basically, we connect virtio frontend (configured by
userspace) to a backend. The backend could be a network device, or a tap
device. Backend is also configured by userspace, including vlan/mac
etc.
Status: This works for me, and I haven't see any crashes.
Compared to userspace, people reported improved latency (as I save up to
4 system calls per packet), as well as better bandwidth and CPU
utilization.
Features that I plan to look at in the future:
- mergeable buffers
- zero copy
- scalability tuning: figure out the best threading model to use
Note on RCU usage (this is also documented in vhost.h, near
private_pointer which is the value protected by this variant of RCU):
what is happening is that the rcu_dereference() is being used in a
workqueue item. The role of rcu_read_lock() is taken on by the start of
execution of the workqueue item, of rcu_read_unlock() by the end of
execution of the workqueue item, and of synchronize_rcu() by
flush_workqueue()/flush_work(). In the future we might need to apply
some gcc attribute or sparse annotation to the function passed to
INIT_WORK(). Paul's ack below is for this RCU usage.
(Includes fixes by Alan Cox <alan@linux.intel.com>,
David L Stevens <dlstevens@us.ibm.com>,
Chris Wright <chrisw@redhat.com>)
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We were shifting the Ks/Kp/N bits one bit too far on mtsrin. It took
me some time to figure that out, so I also put in some debugging and a
comment explaining the conversion.
This fixes current OpenBIOS boot on PPC64 KVM.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
Currently userspace has no chance to find out which virtual address space we're
in and resolve addresses. While that is a big problem for migration, it's also
unpleasent when debugging, as gdb and the monitor don't work on virtual
addresses.
This patch exports enough of the MMU segment state to userspace to make
debugging work and thus also includes the groundwork for migration.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The old BUILD_BUG_ON implementation didn't work with __builtin_constant_p().
Fixing that revealed this test had been inverted for a long time without
anybody noticing...
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
X86 CPUs need to have some magic happening to enable the virtualization
extensions on them. This magic can result in unpleasant results for
users, like blocking other VMMs from working (vmx) or using invalid TLB
entries (svm).
Currently KVM activates virtualization when the respective kernel module
is loaded. This blocks us from autoloading KVM modules without breaking
other VMMs.
To circumvent this problem at least a bit, this patch introduces on
demand activation of virtualization. This means, that instead
virtualization is enabled on creation of the first virtual machine
and disabled on destruction of the last one.
So using this, KVM can be easily autoloaded, while keeping other
hypervisors usable.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Following S390's good example we should use hrtimers for the decrementer too!
This patch converts the timer from the old mechanism to hrtimers.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
It looks like the variable "pc" is defined. At least the current code always
failed on me stating that "pc" is already defined somewhere else.
Let's use _pc instead, because that doesn't collide.
Is this the right approach? Does it break on 440 too? If not, why not?
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Now we have everything in place to be able to build KVM, so let's add it
as config option and in the Makefile.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To be able to keep KVM as module, we need to export the SLB trampoline
addresses to the module, so it knows where to jump to.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Little opcodes behave differently on desktop and embedded PowerPC cores.
In order to reflect those differences, let's add some #ifdef code to emulate.c.
We could probably also handle them in the core specific emulation files, but I
would prefer to reuse as much code as possible.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We support setting the DEC to a certain value right now. Doing that basically
triggers the CPU local timer.
But there's also an mfdec command that enabled the OS to read the decrementor.
This is required at least by all desktop and server PowerPC Linux kernels. It
can't really hurt to allow embedded ones to do it as well though.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
There are generic parts of PowerPC that can be shared across all
implementations and specific parts that only apply to BookE or desktop PPCs.
This patch adds emulation for desktop specific opcodes that don't apply
to BookE CPUs.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This patch adds an implementation for a G3/G4 MMU, so we can run G3 and
G4 guests in KVM on Book3s_64.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To be able to run a guest, we also need to implement a guest MMU.
This patch adds MMU handling for Book3s_64 guests.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We designed the Book3S port of KVM as modular as possible. Most
of the code could be easily used on a Book3S_32 host as well.
The main difference between 32 and 64 bit cores is the MMU. To keep
things well separated, we treat the book3s_64 MMU as one possible compile
option.
This patch adds all the MMU helpers the rest of the code needs in
order to modify the host's MMU, like setting PTEs and segments.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This adds the book3s core handling file. Here everything that is generic to
desktop PowerPC cores is handled, including interrupt injections, MSR settings,
etc.
It basically takes over the same role as booke.c for embedded PowerPCs.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Getting from host state to the guest is only half the story. We also need
to return to our host context and handle whatever happened to get us out of
the guest.
On PowerPC every guest exit is an interrupt. So all we need to do is trap
the host's interrupt handlers and get into our #VMEXIT code to handle it.
PowerPCs also have a register that can add an offset to the interrupt handlers'
adresses which is what the booke KVM code uses. Unfortunately that is a
hypervisor ressource and we also want to be able to run KVM when we're running
in an LPAR. So we have to hook into the Linux interrupt handlers.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is the really low level of guest entry/exit code.
Book3s_64 has an SLB, which stores all ESID -> VSID mappings we're
currently aware of.
The segments in the guest differ from the ones on the host, so we need
to switch the SLB to tell the MMU that we're in a new context.
So we store a shadow of the guest's SLB in the PACA, switch to that on
entry and only restore bolted entries on exit, leaving the rest to the
Linux SLB fault handler.
That way we get a really clean way of switching the SLB.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This is the of entry / exit code. In order to switch between host and guest
context, we need to switch register state and call the exit code handler on
exit.
This assembly file does exactly that. To finally enter the guest it calls
into book3s_64_slb.S. On exit it gets jumped at from book3s_64_slb.S too.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Alexander Graf