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  1. 10 Nov, 2015 13 commits
  3. 05 Nov, 2015 1 commit
    • Kai Huang's avatar
      KVM: VMX: Fix commit which broke PML · a3eaa864
      Kai Huang authored 
      I found PML was broken since below commit:

	commit feda805f
	Author: Xiao Guangrong <guangrong.xiao@linux.intel.com>
	Date:   Wed Sep 9 14:05:55 2015 +0800

	KVM: VMX: unify SECONDARY_VM_EXEC_CONTROL update

	Unify the update in vmx_cpuid_update()
Signed-off-by: default avatarXiao Guangrong <guangrong.xiao@linux.intel.com>
	[Rewrite to use vmcs_set_secondary_exec_control. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>

The reason is in above commit vmx_cpuid_update calls vmx_secondary_exec_control,
in which currently SECONDARY_EXEC_ENABLE_PML bit is cleared unconditionally (as
PML is enabled in creating vcpu). Therefore if vcpu_cpuid_update is called after
vcpu is created, PML will be disabled unexpectedly while log-dirty code still
thinks PML is used.

Fix this by clearing SECONDARY_EXEC_ENABLE_PML in vmx_secondary_exec_control
only when PML is not supported or not enabled (!enable_pml). This is more
reasonable as PML is currently either always enabled or disabled. With this
explicit updating SECONDARY_EXEC_ENABLE_PML in vmx_enable{disable}_pml is not
needed so also rename vmx_enable{disable}_pml to vmx_create{destroy}_pml_buffer.

Fixes: feda805fSigned-off-by: default avatarKai Huang <kai.huang@linux.intel.com>
[While at it, change a wrong ASSERT to an "if".  The condition can happen
 if creating the VCPU fails with ENOMEM. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      a3eaa864
  5. 04 Nov, 2015 16 commits
  7. 02 Nov, 2015 2 commits
  9. 29 Oct, 2015 3 commits
    • Christian Borntraeger's avatar
      KVM: s390: use simple switch statement as multiplexer · 46b708ea
      Christian Borntraeger authored 
      We currently do some magic shifting (by exploiting that exit codes
are always a multiple of 4) and a table lookup to jump into the
exit handlers. This causes some calculations and checks, just to
do an potentially expensive function call.

Changing that to a switch statement gives the compiler the chance
to inline and dynamically decide between jump tables or inline
compare and branches. In addition it makes the code more readable.

bloat-o-meter gives me a small reduction in code size:

add/remove: 0/7 grow/shrink: 1/1 up/down: 986/-1334 (-348)
function                                     old     new   delta
kvm_handle_sie_intercept                      72    1058    +986
handle_prog                                  704     696      -8
handle_noop                                   54       -     -54
handle_partial_execution                      60       -     -60
intercept_funcs                              120       -    -120
handle_instruction                           198       -    -198
handle_validity                              210       -    -210
handle_stop                                  316       -    -316
handle_external_interrupt                    368       -    -368

Right now my gcc does conditional branches instead of jump tables.
The inlining seems to give us enough cycles as some micro-benchmarking
shows minimal improvements, but still in noise.
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
      46b708ea
    • Christian Borntraeger's avatar
      KVM: s390: drop useless newline in debugging data · 58c383c6
      Christian Borntraeger authored 
      the s390 debug feature does not need newlines. In fact it will
result in empty lines. Get rid of 4 leftovers.
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
      58c383c6
    • David Hildenbrand's avatar
      KVM: s390: SCA must not cross page boundaries · c5c2c393
      David Hildenbrand authored 
      We seemed to have missed a few corner cases in commit f6c137ff
("KVM: s390: randomize sca address").

The SCA has a maximum size of 2112 bytes. By setting the sca_offset to
some unlucky numbers, we exceed the page.

0x7c0 (1984) -> Fits exactly
0x7d0 (2000) -> 16 bytes out
0x7e0 (2016) -> 32 bytes out
0x7f0 (2032) -> 48 bytes out

One VCPU entry is 32 bytes long.

For the last two cases, we actually write data to the other page.
1. The address of the VCPU.
2. Injection/delivery/clearing of SIGP externall calls via SIGP IF.

Especially the 2. happens regularly. So this could produce two problems:
1. The guest losing/getting external calls.
2. Random memory overwrites in the host.

So this problem happens on every 127 + 128 created VM with 64 VCPUs.

Cc: stable@vger.kernel.org # v3.15+
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      c5c2c393
  11. 22 Oct, 2015 5 commits
    • Michal Marek's avatar
      KVM: arm: Do not indent the arguments of DECLARE_BITMAP · 5fdf876d
      Michal Marek authored 
      Besides being a coding style issue, it confuses make tags:

ctags: Warning: include/kvm/arm_vgic.h:307: null expansion of name pattern "\1"
ctags: Warning: include/kvm/arm_vgic.h:308: null expansion of name pattern "\1"
ctags: Warning: include/kvm/arm_vgic.h:309: null expansion of name pattern "\1"
ctags: Warning: include/kvm/arm_vgic.h:317: null expansion of name pattern "\1"

Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: default avatarMichal Marek <mmarek@suse.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
      5fdf876d
    • Mark Rutland's avatar
      arm64: kvm: restore EL1N SP for panic · db85c55f
      Mark Rutland authored 
      If we panic in hyp mode, we inject a call to panic() into the EL1N host
kernel. If a guest context is active, we first attempt to restore the
minimal amount of state necessary to execute the host kernel with
restore_sysregs.

However, the SP is restored as part of restore_common_regs, and so we
may return to the host's panic() function with the SP of the guest. Any
calculations based on the SP will be bogus, and any attempt to access
the stack will result in recursive data aborts.

When running Linux as a guest, the guest's EL1N SP is like to be some
valid kernel address. In this case, the host kernel may use that region
as a stack for panic(), corrupting it in the process.

Avoid the problem by restoring the host SP prior to returning to the
host. To prevent misleading backtraces in the host, the FP is zeroed at
the same time. We don't need any of the other "common" registers in
order to panic successfully.
Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: <kvmarm@lists.cs.columbia.edu>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
      db85c55f
    • Christoffer Dall's avatar
      arm/arm64: KVM: Add tracepoints for vgic and timer · e21f0910
      Christoffer Dall authored 
      The VGIC and timer code for KVM arm/arm64 doesn't have any tracepoints
or tracepoint infrastructure defined.  Rewriting some of the timer code
handling showed me how much we need this, so let's add these simple
trace points once and for all and we can easily expand with additional
trace points in these files as we go along.

Cc: Wei Huang <wei@redhat.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
      e21f0910
    • Christoffer Dall's avatar
      arm/arm64: KVM: Improve kvm_exit tracepoint · b5905dc1
      Christoffer Dall authored 
      The ARM architecture only saves the exit class to the HSR (ESR_EL2 for
arm64) on synchronous exceptions, not on asynchronous exceptions like an
IRQ.  However, we only report the exception class on kvm_exit, which is
confusing because an IRQ looks like it exited at some PC with the same
reason as the previous exit.  Add a lookup table for the exception index
and prepend the kvm_exit tracepoint text with the exception type to
clarify this situation.

Also resolve the exception class (EC) to a human-friendly text version
so the trace output becomes immediately usable for debugging this code.

Cc: Wei Huang <wei@redhat.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
      b5905dc1
    • Pavel Fedin's avatar
      KVM: arm/arm64: Fix vGIC documentation · 952105ab
      Pavel Fedin authored 
      Correct some old mistakes in the API documentation:

1. VCPU is identified by index (using kvm_get_vcpu() function), but
   "cpu id" can be mistaken for affinity ID.
2. Some error codes are wrong.

  [ Slightly tweaked some grammer and did some s/CPU index/vcpu_index/
    in the descriptions.  -Christoffer ]
Signed-off-by: default avatarPavel Fedin <p.fedin@samsung.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
      952105ab
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