linux.git/include/linux/kvm_host.h, branch v4.15-rc2

KVM: Let KVM_SET_SIGNAL_MASK work as advertised

2017-11-27T16:53:47+00:00

KVM API says for the signal mask you set via KVM_SET_SIGNAL_MASK, that
"any unblocked signal received [...] will cause KVM_RUN to return with
-EINTR" and that "the signal will only be delivered if not blocked by
the original signal mask".

This, however, is only true, when the calling task has a signal handler
registered for a signal. If not, signal evaluation is short-circuited for
SIG_IGN and SIG_DFL, and the signal is either ignored without KVM_RUN
returning or the whole process is terminated.

Make KVM_SET_SIGNAL_MASK behave as advertised by utilizing logic similar
to that in do_sigtimedwait() to avoid short-circuiting of signals.

Signed-off-by: Jan H. SchÃ¶nherr 
Signed-off-by: Paolo Bonzini

KVM: s390: vsie: use common code functions for pinning

2017-11-09T08:49:47+00:00

We will not see -ENOMEM (gfn_to_hva() will return KVM_ERR_PTR_BAD_PAGE
for all errors). So we can also get rid of special handling in the
callers of pin_guest_page() and always assume that it is a g2 error.

As also kvm_s390_inject_program_int() should never fail, we can
simplify pin_scb(), too.

Signed-off-by: David Hildenbrand 
Message-Id: <20170901151143.22714-1-david@redhat.com>
Acked-by: Cornelia Huck 
Signed-off-by: Christian Borntraeger

KVM: add spinlock optimization framework

2017-08-08T08:57:43+00:00

If a vcpu exits due to request a user mode spinlock, then
the spinlock-holder may be preempted in user mode or kernel mode.
(Note that not all architectures trap spin loops in user mode,
only AMD x86 and ARM/ARM64 currently do).

But if a vcpu exits in kernel mode, then the holder must be
preempted in kernel mode, so we should choose a vcpu in kernel mode
as a more likely candidate for the lock holder.

This introduces kvm_arch_vcpu_in_kernel() to decide whether the
vcpu is in kernel-mode when it's preempted.  kvm_vcpu_on_spin's
new argument says the same of the spinning VCPU.

Signed-off-by: Longpeng(Mike) 
Signed-off-by: Paolo Bonzini

KVM: nVMX: get rid of nested_get_page()

2017-08-07T13:27:00+00:00

nested_get_page() just sounds confusing. All we want is a page from G1.
This is even unrelated to nested.

Let's introduce kvm_vcpu_gpa_to_page() so we don't get too lengthy
lines.

Reviewed-by: Paolo Bonzini 
Signed-off-by: David Hildenbrand 
Signed-off-by: Radim Krčmář 
[Squash pasto fix from Wanpeng Li. - Paolo]
Signed-off-by: Paolo Bonzini

KVM: avoid using rcu_dereference_protected

2017-08-02T20:41:02+00:00

During teardown, accesses to memslots and buses are using
rcu_dereference_protected with an always-true condition because
these accesses are done outside the usual mutexes.  This
is because the last reference is gone and there cannot be any
concurrent modifications, but rcu_dereference_protected is
ugly and unobvious.

Instead, check the refcount in kvm_get_bus and __kvm_memslots.

Signed-off-by: Paolo Bonzini 
Signed-off-by: Radim Krčmář

KVM: make pid available for uevents without debugfs

2017-07-26T16:57:44+00:00

Simplify and improve the code so that the PID is always available in
the uevent even when debugfs is not available.

This adds a userspace_pid field to struct kvm, as per Radim's
suggestion, so that the PID can be retrieved on destruction too.

Acked-by: Janosch Frank 
Fixes: 286de8f6ac9202 ("KVM: trigger uevents when creating or destroying a VM")
Signed-off-by: Claudio Imbrenda 
Signed-off-by: Paolo Bonzini

KVM: use correct accessor function for __kvm_memslots

2017-07-10T10:28:46+00:00

kvm memslots are protected by srcu and not by rcu. We must use
srcu_dereference_check instead of rcu_dereference_check.

Signed-off-by: Christian Borntraeger 
Suggested-by: Paolo Bonzini

KVM: mark memory slots as rcu

2017-07-07T13:24:17+00:00

we access the memslots array via srcu. Mark it as such and
use the right access functions also for the freeing of
memory slots.

Found by sparse:
./include/linux/kvm_host.h:565:16: error: incompatible types in
comparison expression (different address spaces)

Signed-off-by: Christian Borntraeger 
Reviewed-by: Paolo Bonzini

KVM: mark kvm->busses as rcu protected

2017-07-07T13:24:16+00:00

mark kvm->busses as rcu protected and use the correct access
function everywhere.

found by sparse
virt/kvm/kvm_main.c:3490:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3509:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3561:15: error: incompatible types in comparison expression (different address spaces)
virt/kvm/kvm_main.c:3644:15: error: incompatible types in comparison expression (different address spaces)

Signed-off-by: Christian Borntraeger

KVM: mark vcpu->pid pointer as rcu protected

2017-07-07T11:00:19+00:00

We do use rcu to protect the pid pointer. Mark it as such and
adopt all code to use the proper access methods.

This was detected by sparse.
"virt/kvm/kvm_main.c:2248:15: error: incompatible types in comparison
expression (different address spaces)"

Signed-off-by: Christian Borntraeger 
Reviewed-by: Paolo Bonzini