Pull KVM changes from Avi Kivity:
"Changes include additional instruction emulation, page-crossing MMIO,
faster dirty logging, preventing the watchdog from killing a stopped
guest, module autoload, a new MSI ABI, and some minor optimizations
and fixes. Outside x86 we have a small s390 and a very large ppc
update.
Regarding the new (for kvm) rebaseless workflow, some of the patches
that were merged before we switch trees had to be rebased, while
others are true pulls. In either case the signoffs should be correct
now."
Fix up trivial conflicts in Documentation/feature-removal-schedule.txt
arch/powerpc/kvm/book3s_segment.S and arch/x86/include/asm/kvm_para.h.
I suspect the kvm_para.h resolution ends up doing the "do I have cpuid"
check effectively twice (it was done differently in two different
commits), but better safe than sorry ;)
* 'next' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (125 commits)
KVM: make asm-generic/kvm_para.h have an ifdef __KERNEL__ block
KVM: s390: onereg for timer related registers
KVM: s390: epoch difference and TOD programmable field
KVM: s390: KVM_GET/SET_ONEREG for s390
KVM: s390: add capability indicating COW support
KVM: Fix mmu_reload() clash with nested vmx event injection
KVM: MMU: Don't use RCU for lockless shadow walking
KVM: VMX: Optimize %ds, %es reload
KVM: VMX: Fix %ds/%es clobber
KVM: x86 emulator: convert bsf/bsr instructions to emulate_2op_SrcV_nobyte()
KVM: VMX: unlike vmcs on fail path
KVM: PPC: Emulator: clean up SPR reads and writes
KVM: PPC: Emulator: clean up instruction parsing
kvm/powerpc: Add new ioctl to retreive server MMU infos
kvm/book3s: Make kernel emulated H_PUT_TCE available for "PR" KVM
KVM: PPC: bookehv: Fix r8/r13 storing in level exception handler
KVM: PPC: Book3S: Enable IRQs during exit handling
KVM: PPC: Fix PR KVM on POWER7 bare metal
KVM: PPC: Fix stbux emulation
KVM: PPC: bookehv: Use lwz/stw instead of PPC_LL/PPC_STL for 32-bit fields
...
When handling the H_BULK_REMOVE hypercall, we were forgetting to
invalidate and unlock the hashed page table entry (HPTE) in the case
where the page had been paged out. This fixes it by clearing the
first doubleword of the HPTE in that case.
This fixes a regression introduced in commit a92bce95f0 ("KVM: PPC:
Book3S HV: Keep HPTE locked when invalidating"). The effect of the
regression is that the host kernel will sometimes hang when under
memory pressure.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
The code forgot to scramble the VSIDs the way we normally do
and was basically using the "proto VSID" directly with the MMU.
This means that in practice, KVM used random VSIDs that could
collide with segments used by other user space programs.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[agraf: simplify ppc32 case]
Signed-off-by: Alexander Graf <agraf@suse.de>
When jumping back into the kernel to code that knows that it would be
using HSRR registers instead of SRR registers, we need to make sure we
pass it all information on where to jump to in HSRR registers.
Unfortunately, we used r10 to store the information to distinguish between
the HSRR and SRR case. That register got clobbered in between though,
rendering the later comparison invalid.
Instead, let's use cr1 to store this information. That way we don't
need yet another register and everyone's happy.
This fixes PR KVM on POWER7 bare metal for me.
Signed-off-by: Alexander Graf <agraf@suse.de>
When running on a system that is HV capable, some interrupts use HSRR
SPRs instead of the normal SRR SPRs. These are also used in the Linux
handlers to jump back to code after an interrupt got processed.
Unfortunately, in our "jump back to the real host handler after we've
done the context switch" code, we were only setting the SRR SPRs,
rendering Linux to jump back to some invalid IP after it's processed
the interrupt.
This fixes random crashes on p7 opal mode with PR KVM for me.
Signed-off-by: Alexander Graf <agraf@suse.de>
In addition to normal "priviledged instruction" traps, we can also receive
"emulation assist" traps on newer hardware that has the HV bit set.
Handle that one the same way as a privileged instruction, including the
instruction fetching. That way we don't execute old instructions that we
happen to still leave in that field when an emul assist trap comes.
This fixes -M mac99 / -M g3beige on p7 bare metal for me.
Signed-off-by: Alexander Graf <agraf@suse.de>
The H_REGISTER_VPA hcall implementation in HV Power KVM needs to pin some
guest memory pages into host memory so that they can be safely accessed
from usermode. It does this used get_user_pages_fast(). When the VPA is
unregistered, or the VCPUs are cleaned up, these pages are released using
put_page().
However, the get_user_pages() is invoked on the specific memory are of the
VPA which could lie within hugepages. In case the pinned page is huge,
we explicitly find the head page of the compound page before calling
put_page() on it.
At least with the latest kernel, this is not correct. put_page() already
handles finding the correct head page of a compound, and also deals with
various counts on the individual tail page which are important for
transparent huge pages. We don't support transparent hugepages on Power,
but even so, bypassing this count maintenance can lead (when the VM ends)
to a hugepage being released back to the pool with a non-zero mapcount on
one of the tail pages. This can then lead to a bad_page() when the page
is released from the hugepage pool.
This removes the explicit compound_head() call to correct this bug.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When reading and writing SPRs, every SPR emulation piece had to read
or write the respective GPR the value was read from or stored in itself.
This approach is pretty prone to failure. What if we accidentally
implement mfspr emulation where we just do "break" and nothing else?
Suddenly we would get a random value in the return register - which is
always a bad idea.
So let's consolidate the generic code paths and only give the core
specific SPR handling code readily made variables to read/write from/to.
Functionally, this patch doesn't change anything, but it increases the
readability of the code and makes is less prone to bugs.
Signed-off-by: Alexander Graf <agraf@suse.de>
Instructions on PPC are pretty similarly encoded. So instead of
every instruction emulation code decoding the instruction fields
itself, we can move that code to more generic places and rely on
the compiler to optimize the unused bits away.
This has 2 advantages. It makes the code smaller and it makes the
code less error prone, as the instruction fields are always
available, so accidental misusage is reduced.
Functionally, this patch doesn't change anything.
Signed-off-by: Alexander Graf <agraf@suse.de>
This is necessary for qemu to be able to pass the right information
to the guest, such as the supported page sizes and corresponding
encodings in the SLB and hash table, which can vary depending
on the processor type, the type of KVM used (PR vs HV) and the
version of KVM
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[agraf: fix compilation on hv, adjust for newer ioctl numbers]
Signed-off-by: Alexander Graf <agraf@suse.de>
There is nothing in the code for emulating TCE tables in the kernel
that prevents it from working on "PR" KVM... other than ifdef's and
location of the code.
This and moves the bulk of the code there to a new file called
book3s_64_vio.c.
This speeds things up a bit on my G5.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[agraf: fix for hv kvm, 32bit, whitespace]
Signed-off-by: Alexander Graf <agraf@suse.de>
Guest r8 register is held in the scratch register and stored correctly,
so remove the instruction that clobbers it. Guest r13 was missing from vcpu,
store it there.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
While handling an exit, we should listen for interrupts and make sure to
receive them when they arrive, to keep our latencies low.
Signed-off-by: Alexander Graf <agraf@suse.de>
When running on a system that is HV capable, some interrupts use HSRR
SPRs instead of the normal SRR SPRs. These are also used in the Linux
handlers to jump back to code after an interrupt got processed.
Unfortunately, in our "jump back to the real host handler after we've
done the context switch" code, we were only setting the SRR SPRs,
rendering Linux to jump back to some invalid IP after it's processed
the interrupt.
This fixes random crashes on p7 opal mode with PR KVM for me.
Signed-off-by: Alexander Graf <agraf@suse.de>
Stbux writes the address it's operating on to the register specified in ra,
not into the data source register.
Signed-off-by: Alexander Graf <agraf@suse.de>
Interrupt code used PPC_LL/PPC_STL macros to load/store some of u32 fields
which led to memory overflow on 64-bit. Use lwz/stw instead.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
While messing around with the SLBs we're running in real mode. The
entry to guest space goes through rfid, which is context synchronizing,
so there's no need to manually synchronize anything through isync.
With this patch and a simple priviledged SPR access loop guest, I get
a speed bump from 2035607 to 2181301 exits per second.
Signed-off-by: Alexander Graf <agraf@suse.de>
By shuffling a few instructions around we can execute more memory
loads in parallel, giving us a small performance boost.
With this patch and a simple priviledged SPR access loop guest, I get
a speed bump from 2013052 to 2035607 exits per second.
Signed-off-by: Alexander Graf <agraf@suse.de>
For Guest accessible SPRGs 4-7, save/restore must be handled differently for 64bit and
non-64 bit case. Use the PPC_STD/PPC_LD macros for saving/restoring to/from these registers.
Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Introduced PPC_STD/PPC_LD macros for saving/restoring guest registers to/from their 64 bit copies.
Signed-off-by: Varun Sethi <Varun.Sethi@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Time for which the hrtimer is started for decrementer emulation is calculated
using tb_ticks_per_usec. While hrtimer uses the clockevent for DEC
reprogramming (if needed) and which calculate timebase ticks using the
multiplier and shifter mechanism implemented within clockevent layer.
It was observed that this conversion (timebase->time->timebase) are not
correct because the mechanism are not consistent.
In our setup it adds 2% jitter.
With this patch clockevent multiplier and shifter mechanism are used when
starting hrtimer for decrementer emulation. Now the jitter is < 0.5%.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Keep track of minimum and maximum address mapped by tlb1.
This helps in TLBMISS handling in KVM to quick check whether the address lies in mapped range.
If address does not lies in this range then no need to look in each tlb1 entry of tlb1 array.
Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
When the kernel calls into RTAS, it switches to 32-bit mode. The
magic page was is longer accessible in that case, causing the
patched instructions in the RTAS call wrapper to crash.
This fixes it by making available a 32-bit mapping of the magic
page in that case. This mapping is flushed whenever we switch
the kernel back to 64-bit mode.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[agraf: add a check if the magic page is mapped]
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When running kvm_vcpu_block and it realizes that the CPU is actually good
to run, we get a request bit set for KVM_REQ_UNHALT. Right now, there's
nothing we can do with that bit, so let's unset it right after the call
again so we don't get confused in our later checks for pending work.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
When running PR KVM on a p7 system in bare metal, we get HV exits instead
of normal supervisor traps. Semantically they are identical though and the
HSRR vs SRR difference is already taken care of in the exit code.
So all we need to do is handle them in addition to our normal exits.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
