Instead of having the kernel allocate memory to the guest, let userspace
allocate it and pass the address to the kernel.

This is required for s390 support, but also enables features like memory
sharing and using hugetlbfs backed memory.
Signed-off-by: NIzik Eidus <izike@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

The user is now able to set how many mmu pages will be allocated to the guest.
Signed-off-by: NIzik Eidus <izike@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Easier for existence test (#ifdef) in userspace.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This patch adds a new vcpu-based IOCTL to save and restore the local
apic registers for a single vcpu. The kernel only copies the apic page as
a whole, extraction of registers is left to userspace side. On restore, the
APIC timer is restarted from the initial count, this introduces a little
delay, but works fine.
Signed-off-by: NYaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: NQing He <qing.he@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This patch adds support for in-kernel ioapic save and restore (to
and from userspace). It uses the same get/set_irqchip ioctl as
in-kernel PIC.
Signed-off-by: NQing He <qing.he@intel.com>
Signed-off-by: NYaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This patch adds two new ioctls to dump and write kernel irqchips for
save/restore and live migration. PIC s/r and l/m is implemented in this
patch.
Signed-off-by: NYaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: NQing He <qing.he@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

By sleeping in the kernel when hlt is executed, we simplify the in-kernel
guest interrupt path considerably.
Signed-off-by: NGregory Haskins <ghaskins@novell.com>
Signed-off-by: NYaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Because lightweight exits (exits which don't involve userspace) are many
times faster than heavyweight exits, it makes sense to emulate high usage
devices in the kernel.  The local APIC is one such device, especially for
Windows and for SMP, so we add an APIC model to kvm.

It also allows in-kernel host-side drivers to inject interrupts without
going through userspace.

[compile fix on i386 from Jindrich Makovicka]
Signed-off-by: NYaozu (Eddie) Dong <Eddie.Dong@intel.com>
Signed-off-by: NQing He <qing.he@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Signed-off-by: NYaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This allows running 64-bit Windows.
Signed-off-by: NSheng Yang <sheng.yang@intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Add the hypercall number to kvm_run and initialize it.  This changes the ABI,
but as this particular ABI was unusable before this no users are affected.
Signed-off-by: NJeff Dike <jdike@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Creating one's own BITMAP macro seems suboptimal: if we use manual
arithmetic in the one place exposed to userspace, we can use standard
macros elsewhere.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

KVM interface is no longer experimental.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Note that as the size of struct kvm_run is not part of the ABI, we can add
things at the end.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

As we no longer emulate in userspace, this is meaningless.  We don't
compute it on SVM anyway.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

It is illegal not to return from a pio or mmio request without completing
it, as mmio or pio is an atomic operation.  Therefore, we can simplify
the userspace interface by avoiding the completion indication.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

These are really helpful when migrating an floating point app to another
machine.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

With this, we can specify that accesses to one physical memory range will
be remapped to another.  This is useful for the vga window at 0xa0000 which
is used as a movable window into the (much larger) framebuffer.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

The current string pio interface communicates using guest virtual addresses,
relying on userspace to translate addresses and to check permissions.  This
interface cannot fully support guest smp, as the check needs to take into
account two pages at one in case an unaligned string transfer straddles a
page boundary.

Change the interface not to communicate guest addresses at all; instead use
a buffer page (mmaped by userspace) and do transfers there.  The kernel
manages the virtual to physical translation and can perform the checks
atomically by taking the appropriate locks.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This allows us to store offsets in the kernel/user kvm_run area, and be
sure that userspace has them mapped.  As offsets can be outside the
kvm_run struct, userspace has no way of knowing how much to mmap.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Allow a special signal mask to be used while executing in guest mode.  This
allows signals to be used to interrupt a vcpu without requiring signal
delivery to a userspace handler, which is quite expensive.  Userspace still
receives -EINTR and can get the signal via sigwait().
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This is redundant, as we also return -EINTR from the ioctl, but it
allows us to examine the exit_reason field on resume without seeing
old data.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Currently, userspace is told about the nature of the last exit from the
guest using two fields, exit_type and exit_reason, where exit_type has
just two enumerations (and no need for more).  So fold exit_type into
exit_reason, reducing the complexity of determining what really happened.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This is useful for paravirtualized graphics devices, for example.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

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

The recent changes have left the ioctl numbers in complete disarray.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

That ioctl does not transfer any data, so it should be an _IO rather than an
_IOW.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

We no longer emulate single instructions in userspace.  Instead, we service
mmio or pio requests.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

KVM used to handle cpuid by letting userspace decide what values to
return to the guest.  We now handle cpuid completely in the kernel.  We
still let userspace decide which values the guest will see by having
userspace set up the value table beforehand (this is necessary to allow
management software to set the cpu features to the least common denominator,
so that live migration can work).

The motivation for the change is that kvm kernel code can be impacted by
cpuid features, for example the x86 emulator.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Currently when passing the a PIO emulation request to userspace, we
rely on userspace updating %rax (on 'in' instructions) and %rsi/%rdi/%rcx
(on string instructions).  This (a) requires two extra ioctls for getting
and setting the registers and (b) is unfriendly to non-x86 archs, when
they get kvm ports.

So fix by doing the register fixups in the kernel and passing to userspace
only an abstract description of the PIO to be done.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Instead of passing a 'struct kvm_run' back and forth between the kernel and
userspace, allocate a page and allow the user to mmap() it.  This reduces
needless copying and makes the interface expandable by providing lots of
free space.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

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

Allocate a distinct inode for every vcpu in a VM.  This has the following
benefits:

 - the filp cachelines are no longer bounced when f_count is incremented on
   every ioctl()
 - the API and internal code are distinctly clearer; for example, on the
   KVM_GET_REGS ioctl, there is no need to copy the vcpu number from
   userspace and then copy the registers back; the vcpu identity is derived
   from the fd used to make the call

Right now the performance benefits are completely theoretical since (a) we
don't support more than one vcpu per VM and (b) virtualization hardware
inefficiencies completely everwhelm any cacheline bouncing effects.  But
both of these will change, and we need to prepare the API today.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

This avoids having filp->f_op and the corresponding inode->i_fop different,
which is a little unorthodox.

The ioctl list is split into two: global kvm ioctls and per-vm ioctls.  A new
ioctl, KVM_CREATE_VM, is used to create VMs and return the VM fd.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Unfortunately requiring a version bump.
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We report the value of cr8 to userspace on an exit.  Also let userspace change
cr8 when we re-enter the guest.  The lets 64-bit guest code maintain the tpr
correctly.

Thanks for Yaniv Kamay for the idea.
Signed-off-by: NDor Laor <dor.laor@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch implements forwarding of SHUTDOWN intercepts from the guest on to
userspace on AMD SVM.  A SHUTDOWN event occurs when the guest produces a
triple fault (e.g.  on reboot).  This also fixes the bug that a guest reboot
actually causes a host reboot under some circumstances.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current interrupt injection mechanism might delay an interrupt under
the following circumstances:

 - if injection fails because the guest is not interruptible (rflags.IF clear,
   or after a 'mov ss' or 'sti' instruction).  Userspace can check rflags,
   but the other cases or not testable under the current API.
 - if injection fails because of a fault during delivery.  This probably
   never happens under normal guests.
 - if injection fails due to a physical interrupt causing a vmexit so that
   it can be handled by the host.

In all cases the guest proceeds without processing the interrupt, reducing
the interactive feel and interrupt throughput of the guest.

This patch fixes the situation by allowing userspace to request an exit
when the 'interrupt window' opens, so that it can re-inject the interrupt
at the right time.  Guest interactivity is very visibly improved.
Signed-off-by: NDor Laor <dor.laor@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add compile-time and run-time API versioning.
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

web site: http://kvm.sourceforge.net

mailing list: kvm-devel@lists.sourceforge.net
  (http://lists.sourceforge.net/lists/listinfo/kvm-devel)

The following patchset adds a driver for Intel's hardware virtualization
extensions to the x86 architecture.  The driver adds a character device
(/dev/kvm) that exposes the virtualization capabilities to userspace.  Using
this driver, a process can run a virtual machine (a "guest") in a fully
virtualized PC containing its own virtual hard disks, network adapters, and
display.

Using this driver, one can start multiple virtual machines on a host.

Each virtual machine is a process on the host; a virtual cpu is a thread in
that process.  kill(1), nice(1), top(1) work as expected.  In effect, the
driver adds a third execution mode to the existing two: we now have kernel
mode, user mode, and guest mode.  Guest mode has its own address space mapping
guest physical memory (which is accessible to user mode by mmap()ing
/dev/kvm).  Guest mode has no access to any I/O devices; any such access is
intercepted and directed to user mode for emulation.

The driver supports i386 and x86_64 hosts and guests.  All combinations are
allowed except x86_64 guest on i386 host.  For i386 guests and hosts, both pae
and non-pae paging modes are supported.

SMP hosts and UP guests are supported.  At the moment only Intel
hardware is supported, but AMD virtualization support is being worked on.

Performance currently is non-stellar due to the naive implementation of the
mmu virtualization, which throws away most of the shadow page table entries
every context switch.  We plan to address this in two ways:

- cache shadow page tables across tlb flushes
- wait until AMD and Intel release processors with nested page tables

Currently a virtual desktop is responsive but consumes a lot of CPU.  Under
Windows I tried playing pinball and watching a few flash movies; with a recent
CPU one can hardly feel the virtualization.  Linux/X is slower, probably due
to X being in a separate process.

In addition to the driver, you need a slightly modified qemu to provide I/O
device emulation and the BIOS.

Caveats (akpm: might no longer be true):

- The Windows install currently bluescreens due to a problem with the
  virtual APIC.  We are working on a fix.  A temporary workaround is to
  use an existing image or install through qemu
- Windows 64-bit does not work.  That's also true for qemu, so it's
  probably a problem with the device model.

[bero@arklinux.org: build fix]
[simon.kagstrom@bth.se: build fix, other fixes]
[uril@qumranet.com: KVM: Expose interrupt bitmap]
[akpm@osdl.org: i386 build fix]
[mingo@elte.hu: i386 fixes]
[rdreier@cisco.com: add log levels to all printks]
[randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings]
[anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support]
Signed-off-by: NYaniv Kamay <yaniv@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Simon Kagstrom <simon.kagstrom@bth.se>
Cc: Bernhard Rosenkraenzer <bero@arklinux.org>
Signed-off-by: NUri Lublin <uril@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAnthony Liguori <anthony@codemonkey.ws>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>