If the guest executes invlpg, peek into the pagetable and attempt to
prepopulate the shadow entry.

Also stop dirty fault updates from interfering with the fork detector.

2% improvement on RHEL3/AIM7.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Skip syncing global pages on cr3 switch (but not on cr4/cr0). This is
important for Linux 32-bit guests with PAE, where the kmap page is
marked as global.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Collapse remote TLB flushes on root sync.

kernbench is 2.7% faster on 4-way guest. Improvements have been seen
with other loads such as AIM7.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instead of invoking the handler directly collect pages into
an array so the caller can work with it.

Simplifies TLB flush collapsing.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The VMMCALL instruction doesn't get recognised and isn't processed
by the emulator.

This is seen on an Intel host that tries to execute the VMMCALL
instruction after a guest live migrates from an AMD host.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add emulation of shld and shrd instructions
Signed-off-by: NGuillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add the assembler code for instruction with three operands and one
operand is stored in ECX register
Signed-off-by: NGuillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add SrcOne operand type when we need to decode an implied '1' like with
regular shift instruction
Signed-off-by: NGuillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instruction like shld has three operands, so we need to add a Src2
decode set. We start with Src2None, Src2CL, and Src2ImmByte, Src2One to
support shld/shrd and we will expand it later.
Signed-off-by: NGuillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Extend the opcode descriptor to 32 bits. This is needed by the
introduction of a new Src2 operand type.
Signed-off-by: NGuillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Right now, KVM does not remove a slot when we do a
register ioctl for size 0 (would be the expected behaviour).

Instead, we only mark it as empty, but keep all bitmaps
and allocated data structures present. It completely
nullifies our chances of reusing that same slot again
for mapping a different piece of memory.

In this patch, we destroy rmaps, and vfree() the
pointers that used to hold the dirty bitmap, rmap
and lpage_info structures.
Signed-off-by: NGlauber Costa <glommer@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The only significant changes were to kvmppc_exit_timing_write() and
kvmppc_exit_timing_show(), both of which were dramatically simplified.
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Existing KVM statistics are either just counters (kvm_stat) reported for
KVM generally or trace based aproaches like kvm_trace.
For KVM on powerpc we had the need to track the timings of the different exit
types. While this could be achieved parsing data created with a kvm_trace
extension this adds too much overhead (at least on embedded PowerPC) slowing
down the workloads we wanted to measure.

Therefore this patch adds a in-kernel exit timing statistic to the powerpc kvm
code. These statistic is available per vm&vcpu under the kvm debugfs directory.
As this statistic is low, but still some overhead it can be enabled via a
.config entry and should be off by default.

Since this patch touched all powerpc kvm_stat code anyway this code is now
merged and simplified together with the exit timing statistic code (still
working with exit timing disabled in .config).
Signed-off-by: NChristian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Store shadow TLB entries in memory, but only use it on host context switch
(instead of every guest entry). This improves performance for most workloads on
440 by reducing the guest TLB miss rate.
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Formerly, we used to maintain a per-vcpu shadow TLB and on every entry to the
guest would load this array into the hardware TLB. This consumed 1280 bytes of
memory (64 entries of 16 bytes plus a struct page pointer each), and also
required some assembly to loop over the array on every entry.

Instead of saving a copy in memory, we can just store shadow mappings directly
into the hardware TLB, accepting that the host kernel will clobber these as
part of the normal 440 TLB round robin. When we do that we need less than half
the memory, and we have decreased the exit handling time for all guest exits,
at the cost of increased number of TLB misses because the host overwrites some
guest entries.

These savings will be increased on processors with larger TLBs or which
implement intelligent flush instructions like tlbivax (which will avoid the
need to walk arrays in software).

In addition to that and to the code simplification, we have a greater chance of
leaving other host userspace mappings in the TLB, instead of forcing all
subsequent tasks to re-fault all their mappings.
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

KVM currently ignores the host's round robin TLB eviction selection, instead
maintaining its own TLB state and its own round robin index. However, by
participating in the normal 44x TLB selection, we can drop the alternate TLB
processing in KVM. This results in a significant performance improvement,
since that processing currently must be done on *every* guest exit.

Accordingly, KVM needs to be able to access and increment tlb_44x_index.
(KVM on 440 cannot be a module, so there is no need to export this symbol.)
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Acked-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

KVM on 440 has always been able to handle large guest mappings with 4K host
pages -- we must, since the guest kernel uses 256MB mappings.

This patch makes KVM work when the host has large pages too (tested with 64K).
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Split out the logic corresponding to undoing assign_irq() and
clean it up a bit.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Make sure kvm_request_irq_source_id() never returns
KVM_USERSPACE_IRQ_SOURCE_ID.

Likewise, check that kvm_free_irq_source_id() never accepts
KVM_USERSPACE_IRQ_SOURCE_ID.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Set assigned_dev->irq_source_id to -1 so that we can avoid freeing
a source ID which we never allocated.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We never pass a NULL notifier pointer here, but we may well
pass a notifier struct which hasn't previously been
registered.

Guard against this by using hlist_del_init() which will
not do anything if the node hasn't been added to the list
and, when removing the node, will ensure that a subsequent
call to hlist_del_init() will be fine too.

Fixes an oops seen when an assigned device is freed before
and IRQ is assigned to it.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We will obviously never pass a NULL struct kvm_irq_ack_notifier* to
this functions. They are always embedded in the assigned device
structure, so the assertion add nothing.

The irqchip_in_kernel() assertion is very out of place - clearly
this little abstraction needs to know nothing about the upper
layer details.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Impact: make global function static

  arch/x86/kvm/vmx.c:134:3: warning: symbol 'vmx_capability' was not declared. Should it be static?
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Impact: make global function static

  virt/kvm/kvm_main.c:85:6: warning: symbol 'kvm_rebooting' was not declared. Should it be static?
Signed-off-by: NHannes Eder <hannes@hanneseder.net>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Notices by Guillaume Thouvenin.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Set operand type and size to get correct writeback behavior.
Signed-off-by: NAvi Kivity <avi@redhat.com>

'ret' did not set the operand type or size for the destination, so
writeback ignored it.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NAvi Kivity <avi@redhat.com>

Switch 'pop r/m' instruction to use the new function.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add marker_synchronize_unregister() before module unloading.
This prevents possible trace calls into unloaded module text.
Signed-off-by: NWu Fengguang <wfg@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The s390 backend of kvm never calls kvm_vcpu_uninit. This causes
a memory leak of vcpu->run pages.
Lets call kvm_vcpu_uninit in kvm_arch_vcpu_destroy to free
the vcpu->run.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Currently it is impossible to unload the kvm module on s390.
This patch fixes kvm_arch_destroy_vm to release all cpus.
This make it possible to unload the module.

In addition we stop messing with the module refcount in arch code.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NCarsten Otte <cotte@de.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

No need to repeat the same assembly block over and over.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NAvi Kivity <avi@redhat.com>

The write protect verification in set_spte is unnecessary for page sync.

Its guaranteed that, if the unsync spte was writable, the target page
does not have a write protected shadow (if it had, the spte would have
been write protected under mmu_lock by rmap_write_protect before).

Same reasoning applies to mark_page_dirty: the gfn has been marked as
dirty via the pagefault path.

The cost of hash table and memslot lookups are quite significant if the
workload is pagetable write intensive resulting in increased mmu_lock
contention.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Now we use MSI as default one, and translate MSI to INTx when guest need
INTx rather than MSI. For legacy device, we provide support for non-sharing
host IRQ.

Provide a parameter msi2intx for this method. The value is true by default in
x86 architecture.

We can't guarantee this mode can work on every device, but for most of us
tested, it works. If your device encounter some trouble with this mode, you can
try set msi2intx modules parameter to 0. If the device is OK with msi2intx=0,
then please report it to KVM mailing list or me. We may prepare a blacklist for
the device that can't work in this mode.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We enable guest MSI and host MSI support in this patch. The userspace want to
enable MSI should set KVM_DEV_IRQ_ASSIGN_ENABLE_MSI in the assigned_irq's flag.
Function would return -ENOTTY if can't enable MSI, userspace shouldn't set MSI
Enable bit when KVM_ASSIGN_IRQ return -ENOTTY with
KVM_DEV_IRQ_ASSIGN_ENABLE_MSI.

Userspace can tell the support of MSI device from #ifdef KVM_CAP_DEVICE_MSI.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The function is used to dispatch MSI to lapic according to MSI message
address and message data.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

It would be used for MSI in device assignment, for MSI dispatch.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>