linux-stable.git/virt, branch linux-2.6.31.y

KVM: Prevent kvm_init from corrupting debugfs structures

2009-11-10T00:23:10+00:00

commit: 0ea4ed8e948c30f88c824c973ee4b9529015fe65 upstream
 
I'm seeing an oops condition when kvm-intel and kvm-amd are modprobe'd
during boot (say on an Intel system) and then rmmod'd:

   # modprobe kvm-intel
     kvm_init()
     kvm_init_debug()
     kvm_arch_init()  <-- stores debugfs dentries internally
     (success, etc)

   # modprobe kvm-amd
     kvm_init()
     kvm_init_debug() <-- second initialization clobbers kvm's
                          internal pointers to dentries
     kvm_arch_init()
     kvm_exit_debug() <-- and frees them

   # rmmod kvm-intel
     kvm_exit()
     kvm_exit_debug() <-- double free of debugfs files!

     *BOOM*

If execution gets to the end of kvm_init(), then the calling module has been
established as the kvm provider.  Move the debugfs initialization to the end of
the function, and remove the now-unnecessary call to kvm_exit_debug() from the
error path.  That way we avoid trampling on the debugfs entries and freeing
them twice.

Signed-off-by: Darrick J. Wong 
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Greg Kroah-Hartman

KVM: Fix coalesced interrupt reporting in IOAPIC

2009-09-24T15:44:04+00:00

commit 65a82211636f156a276cac3f8665605ae18f371f upstream.

This bug was introduced by b4a2f5e723e4f7df467.

Signed-off-by: Gleb Natapov 
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

KVM: Avoid redelivery of edge interrupt before next edge

2009-08-09T08:45:49+00:00

The check for an edge is broken in current ioapic code. ioapic->irr is
cleared on each edge interrupt by ioapic_service() and this makes
old_irr != ioapic->irr condition in kvm_ioapic_set_irq() to be always
true. The patch fixes the code to properly recognise edge.

Some HW emulation calls set_irq() without level change. If each such
call is propagated to an OS it may confuse a device driver. This is the
case with keyboard device emulation and Windows XP x64  installer on SMP VM.
Each keystroke produce two interrupts (down/up) one interrupt is
submitted to CPU0 and another to CPU1. This confuses Windows somehow
and it ignores keystrokes.

Signed-off-by: Gleb Natapov 
Signed-off-by: Avi Kivity

KVM: fix ack not being delivered when msi present

2009-08-05T11:03:43+00:00

kvm_notify_acked_irq does not check irq type, so that it sometimes
interprets msi vector as irq.  As a result, ack notifiers are not
called, which typially hangs the guest.  The fix is to track and
check irq type.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Avi Kivity

KVM: protect concurrent make_all_cpus_request

2009-06-28T11:10:29+00:00

make_all_cpus_request contains a race condition which can
trigger false request completed status, as follows:

CPU0                                              CPU1

if (test_and_set_bit(req,&vcpu->requests))
   ....                                        	   if (test_and_set_bit(req,&vcpu->requests))
   ..                                                  return
proceed to smp_call_function_many(wait=1)

Use a spinlock to serialize concurrent CPUs.

Cc: stable@kernel.org
Signed-off-by: Andrea Arcangeli 
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Avi Kivity

KVM: Fix dirty bit tracking for slots with large pages

2009-06-28T11:10:29+00:00

When slot is already allocated and being asked to be tracked we need
to break the large pages.

This code flush the mmu when someone ask a slot to start dirty bit
tracking.

Cc: stable@kernel.org
Signed-off-by: Izik Eidus 
Signed-off-by: Avi Kivity

kvm: remove the duplicated cpumask_clear

2009-06-12T03:04:37+00:00

zalloc_cpumask_var already cleared it.

Signed-off-by: Yinghai Lu 
Signed-off-by: Linus Torvalds

KVM: Prevent overflow in largepages calculation

2009-06-10T12:18:16+00:00

If userspace specifies a memory slot that is larger than 8 petabytes, it
could overflow the largepages variable.

Cc: stable@kernel.org
Signed-off-by: Avi Kivity

KVM: Disable large pages on misaligned memory slots

2009-06-10T12:17:58+00:00

If a slots guest physical address and host virtual address unequal (mod
large page size), then we would erronously try to back guest large pages
with host large pages.  Detect this misalignment and diable large page
support for the trouble slot.

Cc: stable@kernel.org
Signed-off-by: Avi Kivity

KVM: take mmu_lock when updating a deleted slot

2009-06-10T08:48:54+00:00

kvm_handle_hva relies on mmu_lock protection to safely access
the memslot structures.

Signed-off-by: Marcelo Tosatti 
Signed-off-by: Avi Kivity