Commit f0a3602c20 ("KVM: Move interrupt injection logic to x86.c") does not
update the cr8 intercept if the lapic is disabled, so when userspace updates
cr8, the cr8 threshold control is not updated and we are left with illegal
control fields.

Fix by explicitly resetting the cr8 threshold.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Choose some allowed error values for the cases VMX returned ENOTSUPP so
far as these values could be returned by the KVM_RUN IOCTL.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

spin_lock disables preemption, so we can simply read the current cpu.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Now KVM allow guest to modify guest's physical address of EPT's identity mapping page.

(change from v1, discard unnecessary check, change ioctl to accept parameter
address rather than value)
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Use kvm_get_gdt() and kvm_read_ldt() to reduce inline assembly code.

Cc: Avi Kivity <avi@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Use get_desc_base() and get_desc_limit() to get the base address and
limit in desc_struct.

Cc: Avi Kivity <avi@redhat.com>
Cc: kvm@vger.kernel.org
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

They are not used by common code without defines which s390 does not
have.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

n_requested_mmu_pages/n_free_mmu_pages are used by
kvm_mmu_change_mmu_pages to calculate the number of pages to zap.

alloc_mmu_pages, called from the vcpu initialization path, modifies this
variables without proper locking, which can result in a negative value
in kvm_mmu_change_mmu_pages (say, with cpu hotplug).
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

set_cr3() should already cover the TLB flushing.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Some Linux versions (f8) try to read EOI register that is write only.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Remove kvm_cpu_has_interrupt() and kvm_arch_interrupt_allowed() from
interface between general code and arch code. kvm_arch_vcpu_runnable()
checks for interrupts instead.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

It is implemented only by x86.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

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

Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

ioeventfd is a mechanism to register PIO/MMIO regions to trigger an eventfd
signal when written to by a guest.  Host userspace can register any
arbitrary IO address with a corresponding eventfd and then pass the eventfd
to a specific end-point of interest for handling.

Normal IO requires a blocking round-trip since the operation may cause
side-effects in the emulated model or may return data to the caller.
Therefore, an IO in KVM traps from the guest to the host, causes a VMX/SVM
"heavy-weight" exit back to userspace, and is ultimately serviced by qemu's
device model synchronously before returning control back to the vcpu.

However, there is a subclass of IO which acts purely as a trigger for
other IO (such as to kick off an out-of-band DMA request, etc).  For these
patterns, the synchronous call is particularly expensive since we really
only want to simply get our notification transmitted asychronously and
return as quickly as possible.  All the sychronous infrastructure to ensure
proper data-dependencies are met in the normal IO case are just unecessary
overhead for signalling.  This adds additional computational load on the
system, as well as latency to the signalling path.

Therefore, we provide a mechanism for registration of an in-kernel trigger
point that allows the VCPU to only require a very brief, lightweight
exit just long enough to signal an eventfd.  This also means that any
clients compatible with the eventfd interface (which includes userspace
and kernelspace equally well) can now register to be notified. The end
result should be a more flexible and higher performance notification API
for the backend KVM hypervisor and perhipheral components.

To test this theory, we built a test-harness called "doorbell".  This
module has a function called "doorbell_ring()" which simply increments a
counter for each time the doorbell is signaled.  It supports signalling
from either an eventfd, or an ioctl().

We then wired up two paths to the doorbell: One via QEMU via a registered
io region and through the doorbell ioctl().  The other is direct via
ioeventfd.

You can download this test harness here:

ftp://ftp.novell.com/dev/ghaskins/doorbell.tar.bz2

The measured results are as follows:

qemu-mmio:       110000 iops, 9.09us rtt
ioeventfd-mmio: 200100 iops, 5.00us rtt
ioeventfd-pio:  367300 iops, 2.72us rtt

I didn't measure qemu-pio, because I have to figure out how to register a
PIO region with qemu's device model, and I got lazy.  However, for now we
can extrapolate based on the data from the NULLIO runs of +2.56us for MMIO,
and -350ns for HC, we get:

qemu-pio:      153139 iops, 6.53us rtt
ioeventfd-hc: 412585 iops, 2.37us rtt

these are just for fun, for now, until I can gather more data.

Here is a graph for your convenience:

http://developer.novell.com/wiki/images/7/76/Iofd-chart.png

The conclusion to draw is that we save about 4us by skipping the userspace
hop.

--------------------
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Today kvm_io_bus_regsiter_dev() returns void and will internally BUG_ON
if it fails.  We want to create dynamic MMIO/PIO entries driven from
userspace later in the series, so we need to enhance the code to be more
robust with the following changes:

   1) Add a return value to the registration function
   2) Fix up all the callsites to check the return code, handle any
      failures, and percolate the error up to the caller.
   3) Add an unregister function that collapses holes in the array
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When kvm is in hpet_legacy_mode, the hpet is providing the timer
interrupt and the pit should not be. So in legacy mode, the pit timer
is destroyed, but the *state* of the pit is maintained. So if kvm or
the guest tries to modify the state of the pit, this modification is
accepted, *except* that the timer isn't actually started. When we exit
hpet_legacy_mode, the current state of the pit (which is up to date
since we've been accepting modifications) is used to restart the pit
timer.

The saved_mode code in kvm_pit_load_count temporarily changes mode to
0xff in order to destroy the timer, but then restores the actual
value, again maintaining "current" state of the pit for possible later
reenablement.

[avi: add some reserved storage in the ioctl; make SET_PIT2 IOW]
[marcelo: fix memory corruption due to reserved storage]
Signed-off-by: NBeth Kon <eak@us.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

We emulate x2apic in software, so host support is not required.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This will save a couple of IPIs.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Acked-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Add tracepoint in msi/ioapic/pic set_irq() functions,
in IPI sending and in the point where IRQ is placed into
apic's IRR.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Irqfd sets level for interrupt to 1 and then to 0.
For MSI, check level so that a single message is sent.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Some Windows versions check whether the BIOS has setup MMI/O for
config space accesses on AMD Fam10h CPUs, we say "no" by returning 0 on
reads and only allow disabling of MMI/O CfgSpace setup by igoring "0" writes.
Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Create, sync, unsync, zap.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Document the basic API corresponding to the 2.6.22 release.
Signed-off-by: NAvi Kivity <avi@redhat.com>

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

This reverts commit 6c20e1442bb1c62914bb85b7f4a38973d2a423ba.

To my understanding, it became obsolete with the advent of the more
robust check in mmu_alloc_roots (89da4ff17f). Moreover, it prevents
the conceptually safe pattern

 1. set sregs
 2. register mem-slots
 3. run vcpu

by setting a sticky triple fault during step 1.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Windows 7 tries to update the CPU's microcode on some processors,
so we ignore the MSR write here. The patchlevel register is already handled
(returning 0), because the MSR number is the same as Intel's.
Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Some in-famous OS do unaligned writing for APIC MMIO, and the return value
has been missed in recent change, then the OS hangs.
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Cosmetic only. No logic is changed by this patch.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch implements MSR interface to local apic as defines by x2apic
Intel specification.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Directed EOI is specified by x2APIC, but is available even when lapic is
in xAPIC mode.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

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

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

Linux guests will try to enable access to the extended PCI config space
via the I/O ports 0xCF8/0xCFC on AMD Fam10h CPU. Since we (currently?)
don't use ECS, simply ignore write and read attempts.
Signed-off-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

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

There is a missing unlock on one fail path in ioapic_mmio_write,
fix that.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Document kvm->lock nesting within kvm->slots_lock
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This changes bus accesses to use high-level kvm_io_bus_read/kvm_io_bus_write
functions. in_range now becomes unused so it is removed from device ops in
favor of read/write callbacks performing range checks internally.

This allows aliasing (mostly for in-kernel virtio), as well as better error
handling by making it possible to pass errors up to userspace.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>