linux-toradex.git/virt, branch v2.6.26-rc9

KVM: ioapic: fix lost interrupt when changing a device's irq

2008-06-24T09:23:55+00:00

The ioapic acknowledge path translates interrupt vectors to irqs.  It
currently uses a first match algorithm, stopping when it finds the first
redirection table entry containing the vector.  That fails however if the
guest changes the irq to a different line, leaving the old redirection table
entry in place (though masked).  Result is interrupts not making it to the
guest.

Fix by always scanning the entire redirection table.

Signed-off-by: Avi Kivity

KVM: IOAPIC: only set remote_irr if interrupt was injected

2008-06-06T18:32:39+00:00

There's a bug in the IOAPIC code for level-triggered interrupts. Its
relatively easy to trigger by sharing (virtio-blk + usbtablet was the
testcase, initially reported by Gerd von Egidy).

The "remote_irr" variable is used to indicate accepted but not yet acked
interrupts. Its cleared from the EOI handler.

Problem is that the EOI handler clears remote_irr unconditionally, even
if it reinjected another pending interrupt.

In that case, kvm_ioapic_set_irq() proceeds to ioapic_service() which
sets remote_irr even if it failed to inject (since the IRR was high due
to EOI reinjection).

Since the TMR bit has been cleared by the first EOI, the second one
fails to clear remote_irr.

End result is interrupt line dead.

Fix it by setting remote_irr only if a new pending interrupt has been
generated (and the TMR bit for vector in question set).

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

KVM: Fix kvm_vcpu_block() task state race

2008-05-18T11:37:12+00:00

There's still a race in kvm_vcpu_block(), if a wake_up_interruptible()
call happens before the task state is set to TASK_INTERRUPTIBLE:

CPU0                            CPU1

kvm_vcpu_block

add_wait_queue

kvm_cpu_has_interrupt = 0
                                set interrupt
                                if (waitqueue_active())
                                        wake_up_interruptible()

kvm_cpu_has_pending_timer
kvm_arch_vcpu_runnable
signal_pending

set_current_state(TASK_INTERRUPTIBLE)
schedule()

Can be fixed by using prepare_to_wait() which sets the task state before
testing for the wait condition.

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

KVM: Export necessary function for EPT

2008-05-04T11:44:40+00:00

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

[PATCH] sanitize anon_inode_getfd()

2008-05-01T17:08:50+00:00

a) none of the callers even looks at inode or file returned by anon_inode_getfd()
b) any caller that would try to look at those would be racy, since by the time
it returns we might have raced with close() from another thread and that
file would be pining for fjords.

Signed-off-by: Al Viro

KVM: kill file->f_count abuse in kvm

2008-04-27T15:21:46+00:00

Use kvm own refcounting instead of playing with ->filp->f_count.
That will allow to get rid of a lot of crap in anon_inode_getfd() and
kill a race in kvm_dev_ioctl_create_vm() (file might have been closed
immediately by another thread, so ->filp might point to already freed
struct file when we get around to setting it).

Signed-off-by: Al Viro 
Signed-off-by: Avi Kivity

KVM: Rename debugfs_dir to kvm_debugfs_dir

2008-04-27T15:21:36+00:00

It's a globally exported symbol now.

Signed-off-by: Hollis Blanchard 
Signed-off-by: Avi Kivity

KVM: add ioctls to save/store mpstate

2008-04-27T15:21:16+00:00

So userspace can save/restore the mpstate during migration.

[avi: export the #define constants describing the value]
[christian: add s390 stubs]
[avi: ditto for ia64]

Signed-off-by: Marcelo Tosatti 
Signed-off-by: Christian Borntraeger 
Signed-off-by: Carsten Otte 
Signed-off-by: Avi Kivity

KVM: hlt emulation should take in-kernel APIC/PIT timers into account

2008-04-27T09:04:11+00:00

Timers that fire between guest hlt and vcpu_block's add_wait_queue() are
ignored, possibly resulting in hangs.

Also make sure that atomic_inc and waitqueue_active tests happen in the
specified order, otherwise the following race is open:

CPU0                                        CPU1
                                            if (waitqueue_active(wq))
add_wait_queue()
if (!atomic_read(pit_timer->pending))
    schedule()
                                            atomic_inc(pit_timer->pending)

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

KVM: Add kvm trace userspace interface

2008-04-27T09:01:22+00:00

This interface allows user a space application to read the trace of kvm
related events through relayfs.

Signed-off-by: Feng (Eric) Liu 
Signed-off-by: Avi Kivity