linux.git/virt/kvm/async_pf.c, branch v3.12

kvm: free resources after canceling async_pf

2013-09-17T09:53:15+00:00

When we cancel 'async_pf_execute()', we should behave as if the work was
never scheduled in 'kvm_setup_async_pf()'.
Fixes a bug when we can't unload module because the vm wasn't destroyed.

Signed-off-by: Radim Krčmář 
Reviewed-by: Paolo Bonzini 
Reviewed-by: Gleb Natapov 
Signed-off-by: Paolo Bonzini

KVM: do not release the error page

2012-08-06T13:04:58+00:00

After commit a2766325cf9f9, the error page is replaced by the
error code, it need not be released anymore

[ The patch has been compiling tested for powerpc ]

Signed-off-by: Xiao Guangrong 
Signed-off-by: Avi Kivity

KVM: introduce KVM_ERR_PTR_BAD_PAGE

2012-08-06T13:04:55+00:00

It is used to eliminate the overload of function call and cleanup
the code

Signed-off-by: Xiao Guangrong 
Signed-off-by: Avi Kivity

KVM: remove dummy pages

2012-07-26T08:55:34+00:00

Currently, kvm allocates some pages and use them as error indicators,
it wastes memory and is not good for scalability

Base on Avi's suggestion, we use the error codes instead of these pages
to indicate the error conditions

Signed-off-by: Xiao Guangrong 
Signed-off-by: Avi Kivity

KVM: use kvm_release_page_clean to release the page

2012-07-26T08:55:31+00:00

In kvm_async_pf_wakeup_all, it uses bad_page to generate broadcast wakeup,
and uses put_page to release bad_page, the work depends on the fact that
bad_page is the normal page. But we will use the error code instead of
bad_page, so use kvm_release_page_clean to release the page which will
release the error code properly

Signed-off-by: Xiao Guangrong 
Signed-off-by: Avi Kivity

KVM: fix the race while wakeup all pv guest

2011-01-12T09:29:03+00:00

In kvm_async_pf_wakeup_all(), we add a dummy apf to vcpu->async_pf.done
without holding vcpu->async_pf.lock, it will break if we are handling apfs
at this time.

Also use 'list_empty_careful()' instead of 'list_empty()'

Signed-off-by: Xiao Guangrong 
Acked-by: Gleb Natapov 
Signed-off-by: Marcelo Tosatti

KVM: handle more completed apfs if possible

2011-01-12T09:29:01+00:00

If it's no need to inject async #PF to PV guest we can handle
more completed apfs at one time, so we can retry guest #PF
as early as possible

Signed-off-by: Xiao Guangrong 
Acked-by: Gleb Natapov 
Signed-off-by: Marcelo Tosatti

KVM: Inject asynchronous page fault into a PV guest if page is swapped out.

2011-01-12T09:23:17+00:00

Send async page fault to a PV guest if it accesses swapped out memory.
Guest will choose another task to run upon receiving the fault.

Allow async page fault injection only when guest is in user mode since
otherwise guest may be in non-sleepable context and will not be able
to reschedule.

Vcpu will be halted if guest will fault on the same page again or if
vcpu executes kernel code.

Acked-by: Rik van Riel 
Signed-off-by: Gleb Natapov 
Signed-off-by: Marcelo Tosatti

KVM: Add PV MSR to enable asynchronous page faults delivery.

2011-01-12T09:23:12+00:00

Guest enables async PF vcpu functionality using this MSR.

Reviewed-by: Rik van Riel 
Signed-off-by: Gleb Natapov 
Signed-off-by: Marcelo Tosatti

KVM: Retry fault before vmentry

2011-01-12T09:23:06+00:00

When page is swapped in it is mapped into guest memory only after guest
tries to access it again and generate another fault. To save this fault
we can map it immediately since we know that guest is going to access
the page. Do it only when tdp is enabled for now. Shadow paging case is
more complicated. CR[034] and EFER registers should be switched before
doing mapping and then switched back.

Acked-by: Rik van Riel 
Signed-off-by: Gleb Natapov 
Signed-off-by: Marcelo Tosatti