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>

Prepared for kvm_arch_assigned_device_msi_dispatch().
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Separate guest irq type and host irq type, for we can support guest using INTx
with host using MSI (but not opposite combination).
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Separate INTx enabling part to a independence function, so that we can add MSI
enabling part easily.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Distinguish common part for device assignment and INTx part, perparing for
refactor later.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Currently, we only set the KVM paravirt signature in case
of CONFIG_KVM_GUEST. However, it is possible to have it turned
off, while CONFIG_KVM_CLOCK is turned on. This is also a paravirt
case, and should be shown accordingly.
Signed-off-by: NGlauber Costa <glommer@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

If we're injecting an interrupt, and another one is pending, request
an interrupt window notification so we don't have excess latency on the
second interrupt.

This shouldn't happen in practice since an EOI will be issued, giving a second
chance to request an interrupt window, but...
Signed-off-by: NAvi Kivity <avi@redhat.com>

Using tab for indentation for vmm_ivt.S.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Since vmm runs in an isolated address space and it is just a copy
of host's kvm-intel module, so once vmm crashes, we just crash all guests
running on it instead of crashing whole kernel.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Use printk infrastructure to print out some debug info once VM crashes.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

kvm-intel module is relocated to an isolated address space
with kernel, so it can't call host kernel's printk for debug
purpose. In the module, we implement the printk to output debug
info of vmm.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

On emergency_restart, we may need to use an NMI to disable virtualization
on all CPUs. We do that using nmi_shootdown_cpus() if VMX is enabled.

Note: With this patch, we will run the NMI stuff only when the CPU where
emergency_restart() was called has VMX enabled. This should work on most
cases because KVM enables VMX on all CPUs, but we may miss the small
window where KVM is doing that. Also, I don't know if all code using
VMX out there always enable VMX on all CPUs like KVM does. We have two
other alternatives for that:

a) Have an API that all code that enables VMX on any CPU should use
   to tell the kernel core that it is going to enable VMX on the CPUs.
b) Always call nmi_shootdown_cpus() if the CPU supports VMX. This is
   a bit intrusive and more risky, as it would run nmi_shootdown_cpus()
   on emergency_reboot() even on systems where virtualization is never
   enabled.

Finding a proper point to hook the nmi_shootdown_cpus() call isn't
trivial, as the non-emergency machine_restart() (that doesn't need the
NMI tricks) uses machine_emergency_restart() directly.

The solution to make this work without adding a new function or argument
to machine_ops was setting a 'reboot_emergency' flag that tells if
native_machine_emergency_restart() needs to do the virt cleanup or not.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We need to disable virtualization extensions on all CPUs before booting
the kdump kernel, otherwise the kdump kernel booting will fail, and
rebooting after the kdump kernel did its task may also fail.

We do it using cpu_emergency_vmxoff() and cpu_emergency_svm_disable(),
that should always work, because those functions check if the CPUs
support SVM or VMX before doing their tasks.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This function can be used by the reboot or kdump code to forcibly
disable SVM on the CPU.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Create cpu_svm_disable() function.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Use a trick to keep the printk()s on has_svm() working as before. gcc
will take care of not generating code for the 'msg' stuff when the
function is called with a NULL msg argument.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add cpu_emergency_vmxoff() and its friends: cpu_vmx_enabled() and
__cpu_emergency_vmxoff().
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Along with some comments on why it is different from the core cpu_vmxoff()
function.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Unfortunately we can't use exactly the same code from vmx
hardware_disable(), because the KVM function uses the
__kvm_handle_fault_on_reboot() tricks.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

It will be used by core code on kdump and reboot, to disable
vmx if needed.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Those definitions will be used by code outside KVM, so move it outside
of a KVM-specific source file.

Those definitions are used only on kvm/vmx.c, that already includes
asm/vmx.h, so they can be moved safely.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

svm.h will be used by core code that is independent of KVM, so I am
moving it outside the arch/x86/kvm directory.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

vmx.h will be used by core code that is independent of KVM, so I am
moving it outside the arch/x86/kvm directory.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We used to defer invalidating userspace TLB entries until jumping out of the
kernel. This was causing MMU weirdness most easily triggered by using a pipe in
the guest, e.g. "dmesg | tail". I believe the problem was that after the guest
kernel changed the PID (part of context switch), the old process's mappings
were still present, and so copy_to_user() on the "return to new process" path
ended up using stale mappings.

Testing with large pages (64K) exposed the problem, probably because with 4K
pages, pressure on the TLB faulted all process A's mappings out before the
guest kernel could insert any for process B.
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Bare metal Linux on 440 can "overmap" RAM in the kernel linear map, so that it
can use large (256MB) mappings even if memory isn't a multiple of 256MB. To
prevent the hardware prefetcher from loading from an invalid physical address
through that mapping, it's marked Guarded.

However, KVM must ensure that all guest mappings are backed by real physical
RAM (since a deliberate access through a guarded mapping could still cause a
machine check). Accordingly, we don't need to make our mappings guarded, so
let's allow prefetching as the designers intended.

Curiously this patch didn't affect performance at all on the quick test I
tried, but it's clearly the right thing to do anyways and may improve other
workloads.
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We have an accessor; might as well use it.
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Commit 7fd49de9773fdcb7b75e823b21c1c5dc1e218c14 "KVM: ensure that memslot
userspace addresses are page-aligned" broke kernel space allocated memory
slot, for the userspace_addr is invalid.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Use kernel's corresponding macro instead.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Make sure that CONFIG_KVM cannot be selected without processor support
(currently, 440 is the only processor implementation available).
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Bad page translation and silent guest failure ensue if the userspace address is
not page-aligned.  I hit this problem using large (host) pages with qemu,
because qemu currently has a hardcoded 4096-byte alignment for guest memory
allocations.
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The code to traverse the cpuid data array list for counting type of leaves is
currently broken.

This patches fixes the 2 things in it.

 1. Set the 1st counting entry's flag KVM_CPUID_FLAG_STATE_READ_NEXT. Without
    it the code will never find a valid entry.

 2. Also the stop condition in the for loop while looking for the next unflaged
    entry is broken. It needs to stop when it find one matching entry;
    and in the case of count of 1, it will be the same entry found in this
    iteration.
Signed-Off-By: NNitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

For cpuid leaf 0xb the bits 8-15 in ECX register define the end of counting
leaf.      The previous code was using bits 0-7 for this purpose, which is
a bug.
Signed-off-by: NNitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>