Currently KVM has a static routing from GSI numbers to interrupts (namely,
0-15 are mapped 1:1 to both PIC and IOAPIC, and 16:23 are mapped 1:1 to
the IOAPIC).  This is insufficient for several reasons:

- HPET requires non 1:1 mapping for the timer interrupt
- MSIs need a new method to assign interrupt numbers and dispatch them
- ACPI APIC mode needs to be able to reassign the PCI LINK interrupts to the
  ioapics

This patch implements an interrupt routing table (as a linked list, but this
can be easily changed) and a userspace interface to replace the table.  The
routing table is initialized according to the current hardwired mapping.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Allow clients to request notifications when the guest masks or unmasks a
particular irq line.  This complements irq ack notifications, as the guest
will not ack an irq line that is masked.

Currently implemented for the ioapic only.
Signed-off-by: NAvi Kivity <avi@redhat.com>

MSI is always enabled by default for msi2intx=1. But if msi2intx=0, we
have to disable MSI if guest require to do so.

The patch also discard unnecessary msi2intx judgment if guest want to update
MSI state.

Notice KVM_DEV_IRQ_ASSIGN_MSI_ACTION is a mask which should cover all MSI
related operations, though we only got one for now.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This rips out the support for KVM_DEBUG_GUEST and introduces a new IOCTL
instead: KVM_SET_GUEST_DEBUG. The IOCTL payload consists of a generic
part, controlling the "main switch" and the single-step feature. The
arch specific part adds an x86 interface for intercepting both types of
debug exceptions separately and re-injecting them when the host was not
interested. Moveover, the foundation for guest debugging via debug
registers is layed.

To signal breakpoint events properly back to userland, an arch-specific
data block is now returned along KVM_EXIT_DEBUG. For x86, the arch block
contains the PC, the debug exception, and relevant debug registers to
tell debug events properly apart.

The availability of this new interface is signaled by
KVM_CAP_SET_GUEST_DEBUG. Empty stubs for not yet supported archs are
provided.

Note that both SVM and VTX are supported, but only the latter was tested
yet. Based on the experience with all those VTX corner case, I would be
fairly surprised if SVM will work out of the box.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

kvm->slots_lock is outer to kvm->lock, so take slots_lock
in kvm_vm_ioctl_assign_device() before taking kvm->lock,
rather than taking it in kvm_iommu_map_memslots().

Cc: stable@kernel.org
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Acked-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Missing buckets and wrong parameter for free_irq()
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

In the past, kvm_get_kvm() and kvm_put_kvm() was called in assigned device irq
handler and interrupt_work, in order to prevent cancel_work_sync() in
kvm_free_assigned_irq got a illegal state when waiting for interrupt_work done.
But it's tricky and still got two problems:

1. A bug ignored two conditions that cancel_work_sync() would return true result
in a additional kvm_put_kvm().

2. If interrupt type is MSI, we would got a window between cancel_work_sync()
and free_irq(), which interrupt would be injected again...

This patch discard the reference count used for irq handler and interrupt_work,
and ensure the legal state by moving the free function at the very beginning of
kvm_destroy_vm(). And the patch fix the second bug by disable irq before
cancel_work_sync(), which may result in nested disable of irq but OK for we are
going to free it.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

kvm_arch_sync_events is introduced to quiet down all other events may happen
contemporary with VM destroy process, like IRQ handler and work struct for
assigned device.

For kvm_arch_sync_events is called at the very beginning of kvm_destroy_vm(), so
the state of KVM here is legal and can provide a environment to quiet down other
events.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The destructor for huge pages uses the backing inode for adjusting
hugetlbfs accounting.

Hugepage mappings are destroyed by exit_mmap, after
mmu_notifier_release, so there are no notifications through
unmap_hugepage_range at this point.

The hugetlbfs inode can be freed with pages backed by it referenced
by the shadow. When the shadow releases its reference, the huge page
destructor will access a now freed inode.

Implement the release operation for kvm mmu notifiers to release page
refs before the hugetlbfs inode is gone.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

In kvm_iommu_unmap_memslots(), assigned_dev_head is already empty.
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Support device deassignment, it can be used in device hotplug.
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

intel iommu APIs are updated, use the new APIs.

In addition, change kvm_iommu_map_guest() to just create the domain, let kvm_iommu_assign_device() assign device.
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

If an assigned device shares a guest irq with an emulated
device then we currently interpret an ack generated by the
emulated device as originating from the assigned device
leading to e.g. "Unbalanced enable for IRQ 4347" from the
enable_irq() in kvm_assigned_dev_ack_irq().

The fix is fairly simple - don't enable the physical device
irq unless it was previously disabled.

Of course, this can still lead to a situation where a
non-assigned device ACK can cause the physical device irq to
be reenabled before the device was serviced. However, being
level sensitive, the interrupt will merely be regenerated.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

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

Userspace might need to act differently.
Signed-off-by: NAvi Kivity <avi@redhat.com>

This changes cpus_hardware_enabled from a cpumask_t to a cpumask_var_t:
equivalent for CONFIG_CPUMASKS_OFFSTACK=n, otherwise dynamically allocated.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We're getting rid on on-stack cpumasks for large NR_CPUS.

1) Use cpumask_var_t/alloc_cpumask_var.
2) smp_call_function_mask -> smp_call_function_many
3) cpus_clear, cpus_empty, cpu_set -> cpumask_clear, cpumask_empty,
   cpumask_set_cpu.

This actually generates slightly smaller code than the old one with
CONFIG_CPUMASKS_OFFSTACK=n.  (gcc knows that cpus cannot be NULL in
that case, where cpumask_var_t is cpumask_t[1]).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Avi said:
> Wow, code duplication from Rusty. Things must be bad.

Something about glass houses comes to mind.  But instead, a patch.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAvi Kivity <avi@redhat.com>

There is a race between a "close of the file descriptors" and module
unload in the kvm module.

You can easily trigger this problem by applying this debug patch:
>--- kvm.orig/virt/kvm/kvm_main.c
>+++ kvm/virt/kvm/kvm_main.c
>@@ -648,10 +648,14 @@ void kvm_free_physmem(struct kvm *kvm)
>                kvm_free_physmem_slot(&kvm->memslots[i], NULL);
> }
>
>+#include <linux/delay.h>
> static void kvm_destroy_vm(struct kvm *kvm)
> {
>        struct mm_struct *mm = kvm->mm;
>
>+       printk("off1\n");
>+       msleep(5000);
>+       printk("off2\n");
>        spin_lock(&kvm_lock);
>        list_del(&kvm->vm_list);
>        spin_unlock(&kvm_lock);

and killing the userspace, followed by an rmmod.

The problem is that kvm_destroy_vm can run while the module count
is 0. That means, you can remove the module while kvm_destroy_vm
is running. But kvm_destroy_vm is part of the module text. This
causes a kerneloops. The race exists without the msleep but is much
harder to trigger.

This patch requires the fix for anon_inodes (anon_inodes: use fops->owner
for module refcount).
With this patch, we can set the owner of all anonymous KVM inodes file
operations. The VFS will then control the KVM module refcount as long as there
is an open file. kvm_destroy_vm will be called by the release function of the
last closed file - before the VFS drops the module refcount.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
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>

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>

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>

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>

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>

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>

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>

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>

Some areas of kvm x86 mmu are using gfn offset inside a slot without
unaliasing the gfn first.  This patch makes sure that the gfn will be
unaliased and add gfn_to_memslot_unaliased() to save the calculating
of the gfn unaliasing in case we have it unaliased already.
Signed-off-by: NIzik Eidus <ieidus@redhat.com>
Acked-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Ideally, every assigned device should in a clear condition before and after
assignment, so that the former state of device won't affect later work.
Some devices provide a mechanism named Function Level Reset, which is
defined in PCI/PCI-e document. We should execute it before and after device
assignment.

(But sadly, the feature is new, and most device on the market now don't
support it. We are considering using D0/D3hot transmit to emulate it later,
but not that elegant and reliable as FLR itself.)

[Update: Reminded by Xiantao, execute FLR after we ensure that the device can
be assigned to the guest.]
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Also remove unnecessary parameter of unregister irq ack notifier.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Every call of kvm_set_irq() should offer an irq_source_id, which is
allocated by kvm_request_irq_source_id(). Based on irq_source_id, we
identify the irq source and implement logical OR for shared level
interrupts.

The allocated irq_source_id can be freed by kvm_free_irq_source_id().

Currently, we support at most sizeof(unsigned long) different irq sources.

[Amit: - rebase to kvm.git HEAD
       - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file
       - move kvm_request_irq_source_id to the update_irq ioctl]

[Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests]
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add a kvm_ prefix to avoid polluting kernel's name space.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

To share with other archs, this patch moves device assignment
logic to common parts.
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Assigned device could DMA to mmio pages, so also need to map mmio pages
into VT-d page table.
Signed-off-by: NWeidong Han <weidong.han@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>