linux-toradex.git/virt, branch v2.6.31-rc5

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

KVM: protect assigned dev workqueue, int handler and irq acker

2009-06-10T08:48:53+00:00

kvm_assigned_dev_ack_irq is vulnerable to a race condition with the
interrupt handler function. It does:

        if (dev->host_irq_disabled) {
                enable_irq(dev->host_irq);
                dev->host_irq_disabled = false;
        }

If an interrupt triggers before the host->dev_irq_disabled assignment,
it will disable the interrupt and set dev->host_irq_disabled to true.

On return to kvm_assigned_dev_ack_irq, dev->host_irq_disabled is set to
false, and the next kvm_assigned_dev_ack_irq call will fail to reenable
it.

Other than that, having the interrupt handler and work handlers run in
parallel sounds like asking for trouble (could not spot any obvious
problem, but better not have to, its fragile).

CC: sheng.yang@intel.com
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Avi Kivity

KVM: Trivial format fix in setup_routing_entry()

2009-06-10T08:48:50+00:00

Remove extra tab.

Signed-off-by: Chris Wright 
Signed-off-by: Avi Kivity

KVM: VMX: Disable VMX when system shutdown

2009-06-10T08:48:50+00:00

Intel TXT(Trusted Execution Technology) required VMX off for all cpu to work
when system shutdown.

CC: Joseph Cihula 
Signed-off-by: Sheng Yang 
Signed-off-by: Avi Kivity

KVM: Enable snooping control for supported hardware

2009-06-10T08:48:50+00:00

Memory aliases with different memory type is a problem for guest. For the guest
without assigned device, the memory type of guest memory would always been the
same as host(WB); but for the assigned device, some part of memory may be used
as DMA and then set to uncacheable memory type(UC/WC), which would be a conflict of
host memory type then be a potential issue.

Snooping control can guarantee the cache correctness of memory go through the
DMA engine of VT-d.

[avi: fix build on ia64]

Signed-off-by: Sheng Yang 
Signed-off-by: Avi Kivity