Only remove write access in the last sptes.
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The goal of this document shall be
- overview of all locks used in KVM core
- provide details on the scope of each lock
- explain the lock type, specifically of a raw spin locks
- provide a lock ordering guide
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

use EFER_SCE, EFER_LME and EFER_LMA instead of magic numbers.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The hash array of async gfns may still contain some left gfns after
kvm_clear_async_pf_completion_queue() called, need to clear them.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Currently vm86 task is initialized on each real mode entry and vcpu
reset. Initialization is done by zeroing TSS and updating relevant
fields. But since all vcpus are using the same TSS there is a race where
one vcpu may use TSS while other vcpu is initializing it, so the vcpu
that uses TSS will see wrong TSS content and will behave incorrectly.
Fix that by initializing TSS only once.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When rmode.vm86 is active TR descriptor is updated with vm86 task values,
but selector is left intact. vmx_set_segment() makes sure that if TR
register is written into while vm86 is active the new values are saved
for use after vm86 is deactivated, but since selector is not updated on
vm86 activation/deactivation new value is lost. Fix this by writing new
selector into vmcs immediately.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

The changelog of 104f226b said "adds the __noclone attribute",
but it was missing in its patch. I think it is still needed.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

isr_ack logic was added by e4825800 to avoid unnecessary IPIs. Back
then it made sense, but now the code checks that vcpu is ready to accept
interrupt before sending IPI, so this logic is no longer needed. The
patch removes it.

Fixes a regression with Debian/Hurd.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Reported-and-tested-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch fixes the logic used to detect whether BIOS has disabled VMX, for
the case where VMX is enabled only under SMX, but tboot is not active.
Signed-off-by: NJoseph Cihula <joseph.cihula@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Code under this lock requires non-preemptibility. Ensure this also over
-rt by converting it to raw spinlock.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When we enable an NMI window, we ask for an IRET intercept, since
the IRET re-enables NMIs.  However, the IRET intercept happens before
the instruction executes, while the NMI window architecturally opens
afterwards.

To compensate for this mismatch, we only open the NMI window in the
following exit, assuming that the IRET has by then executed; however,
this assumption is not always correct; we may exit due to a host interrupt
or page fault, without having executed the instruction.

Fix by checking for forward progress by recording and comparing the IRET's
rip.  This is somewhat of a hack, since an unchaging rip does not mean that
no forward progress has been made, but is the simplest fix for now.
Signed-off-by: NAvi Kivity <avi@redhat.com>

The interrupt injection logic looks something like

  if an nmi is pending, and nmi injection allowed
    inject nmi
  if an nmi is pending
    request exit on nmi window

the problem is that "nmi is pending" can be set asynchronously by
the PIT; if it happens to fire between the two if statements, we
will request an nmi window even though nmi injection is allowed.  On
SVM, this has disasterous results, since it causes eflags.TF to be
set in random guest code.

The fix is simple; make nmi_pending synchronous using the standard
vcpu->requests mechanism; this ensures the code above is completely
synchronous wrt nmi_pending.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Instead of sleeping in kvm_vcpu_on_spin, which can cause gigantic
slowdowns of certain workloads, we instead use yield_to to get
another VCPU in the same KVM guest to run sooner.

This seems to give a 10-15% speedup in certain workloads.
Signed-off-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Keep track of which task is running a KVM vcpu.  This helps us
figure out later what task to wake up if we want to boost a
vcpu that got preempted.

Unfortunately there are no guarantees that the same task
always keeps the same vcpu, so we can only track the task
across a single "run" of the vcpu.
Signed-off-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Export the symbols required for a race-free kvm_vcpu_on_spin.
Signed-off-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Use the new support in the emulator, and drop the ad-hoc code in x86.c.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Mark some instructions as vendor specific, and allow the caller to request
emulation only of vendor specific instructions.  This is useful in some
circumstances (responding to a #UD fault).
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

x86_decode_insn() doesn't return X86EMUL_* values, so the check
for X86EMUL_PROPOGATE_FAULT will always fail.  There is a proper
check later on, so there is no need for a replacement for this
code.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This warning was once used for debugging QEMU user space. Though
uncommon, it is actually possible to send an INIT request to a running
VCPU. So better drop this warning before someone misuses it to flood
kernel logs this way.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When a vcpu is reset, kvmclock page keeps being written to this days.
This is wrong and inconsistent: a cpu reset should take it to its
initial state.
Signed-off-by: NGlauber Costa <glommer@redhat.com>
CC: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Unused.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

is_hwpoison_address only checks whether the page table entry is
hwpoisoned, regardless the memory page mapped.  While __get_user_pages
will check both.

QEMU will clear the poisoned page table entry (via unmap/map) to make
it possible to allocate a new memory page for the virtual address
across guest rebooting.  But it is also possible that the underlying
memory page is kept poisoned even after the corresponding page table
entry is cleared, that is, a new memory page can not be allocated.
__get_user_pages can catch these situations.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Make __get_user_pages return -EHWPOISON for HWPOISON page only if
FOLL_HWPOISON is specified.  With this patch, the interested callers
can distinguish HWPOISON pages from general FAULT pages, while other
callers will still get -EFAULT for all these pages, so the user space
interface need not to be changed.

This feature is needed by KVM, where UCR MCE should be relayed to
guest for HWPOISON page, while instruction emulation and MMIO will be
tried for general FAULT page.

The idea comes from Andrew Morton.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

In most cases, get_user_pages and get_user_pages_fast should be used
to pin user pages in memory.  But sometimes, some special flags except
FOLL_GET, FOLL_WRITE and FOLL_FORCE are needed, for example in
following patch, KVM needs FOLL_HWPOISON.  To support these users,
__get_user_pages is exported directly.

There are some symbol name conflicts in infiniband driver, fixed them too.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Michel Lespinasse <walken@google.com>
CC: Roland Dreier <roland@kernel.org>
CC: Ralph Campbell <infinipath@qlogic.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

A correction to Intel cpu model CPUID data (patch queued)
caused winxp to BSOD when booted with a Penryn model.
This was traced to the CPUID "model" field correction from
6 -> 23 (as is proper for a Penryn class of cpu).  Only in
this case does the problem surface.

The cause for this failure is winxp accessing the BBL_CR_CTL3
MSR which is unsupported by current kvm, appears to be a
legacy MSR not fully characterized yet existing in current
silicon, and is apparently carried forward in MSR space to
accommodate vintage code as here.  It is not yet conclusive
whether this MSR implements any of its legacy functionality
or is just an ornamental dud for compatibility.  While I
found no silicon version specific documentation link to
this MSR, a general description exists in Intel's developer's
reference which agrees with the functional behavior of
other bootloader/kernel code I've examined accessing
BBL_CR_CTL3.  Regrettably winxp appears to be setting bit #19
called out as "reserved" in the above document.

So to minimally accommodate this MSR, kvm msr get will provide
the equivalent mock data and kvm msr write will simply toss the
guest passed data without interpretation.  While this treatment
of BBL_CR_CTL3 addresses the immediate problem, the approach may
be modified pending clarification from Intel.
Signed-off-by: Njohn cooper <john.cooper@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Now, we have 'vcpu->mode' to judge whether need to send ipi to other
cpus, this way is very exact, so checking request bit is needless,
then we can drop the spinlock let it's collateral
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Currently we keep track of only two states: guest mode and host
mode.  This patch adds an "exiting guest mode" state that tells
us that an IPI will happen soon, so unless we need to wait for the
IPI, we can avoid it completely.

Also
1: No need atomically to read/write ->mode in vcpu's thread

2: reorganize struct kvm_vcpu to make ->mode and ->requests
   in the same cache line explicitly
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Get rid of this warning:

  CC      arch/s390/kvm/../../../virt/kvm/kvm_main.o
arch/s390/kvm/../../../virt/kvm/kvm_main.c:596:12: warning: 'kvm_create_dirty_bitmap' defined but not used

The only caller of the function is within a !CONFIG_S390 section, so add the
same ifdef around kvm_create_dirty_bitmap() as well.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

This case is a pure user space error we do not need to record. Moreover,
it can be misused to flood the kernel log. Remove it.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Fix:

[ 1001.499596] ===================================================
[ 1001.499599] [ INFO: suspicious rcu_dereference_check() usage. ]
[ 1001.499601] ---------------------------------------------------
[ 1001.499604] include/linux/kvm_host.h:301 invoked rcu_dereference_check() without protection!
	......
[ 1001.499636] Pid: 6035, comm: qemu-system-x86 Not tainted 2.6.37-rc6+ #62
[ 1001.499638] Call Trace:
[ 1001.499644]  [] lockdep_rcu_dereference+0x9d/0xa5
[ 1001.499653]  [] gfn_to_memslot+0x8d/0xc8 [kvm]
[ 1001.499661]  [] gfn_to_hva+0x16/0x3f [kvm]
[ 1001.499669]  [] kvm_read_guest_page+0x1e/0x5e [kvm]
[ 1001.499681]  [] kvm_read_guest_page_mmu+0x53/0x5e [kvm]
[ 1001.499699]  [] load_pdptrs+0x3f/0x9c [kvm]
[ 1001.499705]  [] ? vmx_set_cr0+0x507/0x517 [kvm_intel]
[ 1001.499717]  [] kvm_arch_vcpu_ioctl_set_sregs+0x1f3/0x3c0 [kvm]
[ 1001.499727]  [] kvm_vcpu_ioctl+0x6a5/0xbc5 [kvm]
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Instead of exchanging the guest and host rcx, have separate storage
for each.  This allows us to avoid using the xchg instruction, which
is is a little slower than normal operations.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Change

  push top-of-stack
  pop guest-rcx
  pop dummy

to

  pop guest-rcx

which is the same thing, only simpler.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

On some CPUs, a ple_gap of 41 is simply insufficient to ever trigger
PLE exits, even with the minimalistic PLE test from kvm-unit-tests.

http://git.kernel.org/?p=virt/kvm/kvm-unit-tests.git;a=commitdiff;h=eda71b28fa122203e316483b35f37aaacd42f545

For example, the Xeon X5670 CPU needs a ple_gap of at least 48 in
order to get pause loop exits:

# modprobe kvm_intel ple_gap=47
# taskset 1 /usr/local/bin/qemu-system-x86_64 \
  -device testdev,chardev=log -chardev stdio,id=log \
  -kernel x86/vmexit.flat -append ple-round-robin -smp 2
VNC server running on `::1:5900'
enabling apic
enabling apic
ple-round-robin 58298446
# rmmod kvm_intel
# modprobe kvm_intel ple_gap=48
# taskset 1 /usr/local/bin/qemu-system-x86_64 \
   -device testdev,chardev=log -chardev stdio,id=log \
   -kernel x86/vmexit.flat -append ple-round-robin -smp 2
VNC server running on `::1:5900'
enabling apic
enabling apic
ple-round-robin 36616

Increase the ple_gap to 128 to be on the safe side.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NZhai, Edwin <edwin.zhai@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

This patch adds the necessary code to run perf-kvm on AMD
machines.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

When emulating real mode, we fake some state:

 - tr.base points to a fake vm86 tss
 - segment registers are made to conform to vm86 restrictions

change vmx_get_segment() not to expose this fake state to userspace;
instead, return the original state.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When emulating real mode we play with tr hidden state, but leave
tr.selector alone.  That works well, except for save/restore, since
loading TR writes it to the hidden state in vmx->rmode.

Fix by also saving and restoring the tr selector; this makes things
more consistent and allows migration to work during the early
boot stages of Windows XP.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Previously SPRGs 4-7 were improperly read and written in
kvm_arch_vcpu_ioctl_get_regs() and kvm_arch_vcpu_ioctl_set_regs();
Signed-off-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NPeter Tyser <ptyser@xes-inc.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

WARNING: arch/x86/built-in.o(.text+0x1bb74): Section mismatch in reference from the function kvm_guest_cpu_online() to the function .cpuinit.text:kvm_guest_cpu_init()
The function kvm_guest_cpu_online() references
the function __cpuinit kvm_guest_cpu_init().
This is often because kvm_guest_cpu_online lacks a __cpuinit
annotation or the annotation of kvm_guest_cpu_init is wrong.

This patch fixes the warning.

Tested with linux-next (next-20101231)
Signed-off-by: NSedat Dilek <sedat.dilek@gmail.com>
Acked-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

Instead, drop large mappings, which were the reason we dropped shadow.
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>