linux-toradex.git/include/linux/kvm_host.h, branch v2.6.31.7

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: 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: use smp_send_reschedule in kvm_vcpu_kick

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

KVM uses a function call IPI to cause the exit of a guest running on a
physical cpu. For virtual interrupt notification there is no need to
wait on IPI receival, or to execute any function.

This is exactly what the reschedule IPI does, without the overhead
of function IPI. So use it instead of smp_call_function_single in
kvm_vcpu_kick.

Also change the "guest_mode" variable to a bit in vcpu->requests, and
use that to collapse multiple IPI's that would be issued between the
first one and zeroing of guest mode.

This allows kvm_vcpu_kick to called with interrupts disabled.

Signed-off-by: Marcelo Tosatti 
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

KVM: Fix interrupt unhalting a vcpu when it shouldn't

2009-06-10T08:48:33+00:00

kvm_vcpu_block() unhalts vpu on an interrupt/timer without checking
if interrupt window is actually opened.

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

KVM: Device assignment framework rework

2009-06-10T08:48:29+00:00

After discussion with Marcelo, we decided to rework device assignment framework
together. The old problems are kernel logic is unnecessary complex. So Marcelo
suggest to split it into a more elegant way:

1. Split host IRQ assign and guest IRQ assign. And userspace determine the
combination. Also discard msi2intx parameter, userspace can specific
KVM_DEV_IRQ_HOST_MSI | KVM_DEV_IRQ_GUEST_INTX in assigned_irq->flags to
enable MSI to INTx convertion.

2. Split assign IRQ and deassign IRQ. Import two new ioctls:
KVM_ASSIGN_DEV_IRQ and KVM_DEASSIGN_DEV_IRQ.

This patch also fixed the reversed _IOR vs _IOW in definition(by deprecated the
old interface).

[avi: replace homemade bitcount() by hweight_long()]

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

KVM: consolidate ioapic/ipi interrupt delivery logic

2009-06-10T08:48:27+00:00

Use kvm_apic_match_dest() in kvm_get_intr_delivery_bitmask() instead
of duplicating the same code. Use kvm_get_intr_delivery_bitmask() in
apic_send_ipi() to figure out ipi destination instead of reimplementing
the logic.

Signed-off-by: Gleb Natapov 
Signed-off-by: Marcelo Tosatti

KVM: ioapic/msi interrupt delivery consolidation

2009-06-10T08:48:27+00:00

ioapic_deliver() and kvm_set_msi() have code duplication. Move
the code into ioapic_deliver_entry() function and call it from
both places.

Signed-off-by: Gleb Natapov 
Signed-off-by: Marcelo Tosatti

KVM: declare ioapic functions only on affected hardware

2009-06-10T08:48:24+00:00

Since "KVM: Unify the delivery of IOAPIC and MSI interrupts"
I get the following warnings:

  CC [M]  arch/s390/kvm/kvm-s390.o
In file included from arch/s390/kvm/kvm-s390.c:22:
include/linux/kvm_host.h:357: warning: 'struct kvm_ioapic' declared inside parameter list
include/linux/kvm_host.h:357: warning: its scope is only this definition or declaration, which is probably not what you want

This patch limits IOAPIC functions for architectures that have one.

Signed-off-by: Christian Borntraeger 
Signed-off-by: Avi Kivity