linux-stable.git/arch, branch v3.3.6

ARM: 7398/1: l2x0: only write to debug registers on PL310

2012-05-12T16:32:22+00:00

commit ab4d536890853ab6675ede65db40e2c0980cb0ea upstream.

PL310 errata #588369 and #727915 require writes to the debug registers
of the cache controller to work around known problems. Writing these
registers on L220 may cause deadlock, so ensure that we only perform
this operation when we identify a PL310 at probe time.

Signed-off-by: Will Deacon 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman

ARM: 7397/1: l2x0: only apply workaround for erratum #753970 on PL310

2012-05-12T16:32:21+00:00

commit f154fe9b806574437b47f08e924ad10c0e240b23 upstream.

The workaround for PL310 erratum #753970 can lead to deadlock on systems
with an L220 cache controller.

This patch makes the workaround effective only when the cache controller
is identified as a PL310 at probe time.

Signed-off-by: Will Deacon 
Signed-off-by: Russell King 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: Fix kvm_set_shared_msr() called in preemptible context

2012-05-12T16:32:20+00:00

(cherry picked from commit 2225fd56049643c1a7d645c0ce9d499d43c7974e)

kvm_set_shared_msr() may not be called in preemptible context,
but vmx_set_msr() does so:

  BUG: using smp_processor_id() in preemptible [00000000] code: qemu-kvm/22713
  caller is kvm_set_shared_msr+0x32/0xa0 [kvm]
  Pid: 22713, comm: qemu-kvm Not tainted 3.4.0-rc3+ #39
  Call Trace:
   [] debug_smp_processor_id+0xe2/0x100
   [] kvm_set_shared_msr+0x32/0xa0 [kvm]
   [] vmx_set_msr+0x28b/0x2d0 [kvm_intel]
   ...

Making kvm_set_shared_msr() work in preemptible is cleaner, but
it's used in the fast path.  Making two variants is overkill, so
this patch just disables preemption around the call.

Reported-by: Dave Jones 
Signed-off-by: Avi Kivity 
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: vmx_set_cr0 expects kvm->srcu locked

2012-05-12T16:32:20+00:00

(cherry picked from commit 7a4f5ad051e02139a9f1c0f7f4b1acb88915852b)

vmx_set_cr0 is called from vcpu run context, therefore it expects
kvm->srcu to be held (for setting up the real-mode TSS).

Signed-off-by: Marcelo Tosatti 
Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

KVM: nVMX: Fix erroneous exception bitmap check

2012-05-12T16:32:20+00:00

(cherry picked from commit 9587190107d0c0cbaccbf7bf6b0245d29095a9ae)

The code which checks whether to inject a pagefault to L1 or L2 (in
nested VMX) was wrong, incorrect in how it checked the PF_VECTOR bit.
Thanks to Dan Carpenter for spotting this.

Signed-off-by: Nadav Har'El 
Reported-by: Dan Carpenter 
Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: Fix delayed load of shared MSRs

2012-05-12T16:32:20+00:00

(cherry picked from commit 9ee73970c03edb68146ceb1ba2a7033c99a5e017)

Shared MSRs (MSR_*STAR and related) are stored in both vmx->guest_msrs
and in the CPU registers, but vmx_set_msr() only updated memory. Prior
to 46199f33c2953, this didn't matter, since we called vmx_load_host_state(),
which scheduled a vmx_save_host_state(), which re-synchronized the CPU
state, but now we don't, so the CPU state will not be synchronized until
the next exit to host userspace.  This mostly affects nested vmx workloads,
which play with these MSRs a lot.

Fix by loading the MSR eagerly.

Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

KVM: Ensure all vcpus are consistent with in-kernel irqchip settings

2012-05-12T16:32:20+00:00

(cherry picked from commit 3e515705a1f46beb1c942bb8043c16f8ac7b1e9e)

If some vcpus are created before KVM_CREATE_IRQCHIP, then
irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading
to potential NULL pointer dereferences.

Fix by:
- ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called
- ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP

This is somewhat long winded because vcpu->arch.apic is created without
kvm->lock held.

Based on earlier patch by Michael Ellerman.

Signed-off-by: Michael Ellerman 
Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

KVM: x86 emulator: correctly mask pmc index bits in RDPMC instruction emulation

2012-05-12T16:32:20+00:00

(cherry picked from commit 270c6c79f4e15e599f47174ecedad932463af7a2)


Signed-off-by: Gleb Natapov 
Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

KVM: Fix write protection race during dirty logging

2012-05-12T16:32:19+00:00

(cherry picked from commit 6dbf79e7164e9a86c1e466062c48498142ae6128)

This patch fixes a race introduced by:

  commit 95d4c16ce78cb6b7549a09159c409d52ddd18dae
  KVM: Optimize dirty logging by rmap_write_protect()

During protecting pages for dirty logging, other threads may also try
to protect a page in mmu_sync_children() or kvm_mmu_get_page().

In such a case, because get_dirty_log releases mmu_lock before flushing
TLB's, the following race condition can happen:

  A (get_dirty_log)     B (another thread)

  lock(mmu_lock)
  clear pte.w
  unlock(mmu_lock)
                        lock(mmu_lock)
                        pte.w is already cleared
                        unlock(mmu_lock)
                        skip TLB flush
                        return
  ...
  TLB flush

Though thread B assumes the page has already been protected when it
returns, the remaining TLB entry will break that assumption.

This patch fixes this problem by making get_dirty_log hold the mmu_lock
until it flushes the TLB's.

Signed-off-by: Takuya Yoshikawa 
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman

KVM: s390: Sanitize fpc registers for KVM_SET_FPU

2012-05-12T16:32:19+00:00

(cherry picked from commit 851755871c1f3184f4124c466e85881f17fa3226)

commit 7eef87dc99e419b1cc051e4417c37e4744d7b661 (KVM: s390: fix
register setting) added a load of the floating point control register
to the KVM_SET_FPU path. Lets make sure that the fpc is valid.

Signed-off-by: Christian Borntraeger 
Signed-off-by: Marcelo Tosatti 
Signed-off-by: Avi Kivity 
Signed-off-by: Greg Kroah-Hartman