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  1. 01 3月, 2010 4 次提交
  3. 03 12月, 2009 1 次提交
    • Z
      KVM: VMX: Add support for Pause-Loop Exiting · 4b8d54f9
      由 Zhai, Edwin 提交于 
      New NHM processors will support Pause-Loop Exiting by adding 2 VM-execution
control fields:
PLE_Gap    - upper bound on the amount of time between two successive
             executions of PAUSE in a loop.
PLE_Window - upper bound on the amount of time a guest is allowed to execute in
             a PAUSE loop

If the time, between this execution of PAUSE and previous one, exceeds the
PLE_Gap, processor consider this PAUSE belongs to a new loop.
Otherwise, processor determins the the total execution time of this loop(since
1st PAUSE in this loop), and triggers a VM exit if total time exceeds the
PLE_Window.
* Refer SDM volume 3b section 21.6.13 & 22.1.3.

Pause-Loop Exiting can be used to detect Lock-Holder Preemption, where one VP
is sched-out after hold a spinlock, then other VPs for same lock are sched-in
to waste the CPU time.

Our tests indicate that most spinlocks are held for less than 212 cycles.
Performance tests show that with 2X LP over-commitment we can get +2% perf
improvement for kernel build(Even more perf gain with more LPs).
Signed-off-by: NZhai Edwin <edwin.zhai@intel.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
      4b8d54f9
  5. 10 9月, 2009 2 次提交
  7. 10 6月, 2009 1 次提交
    • A
      KVM: Add VT-x machine check support · a0861c02
      由 Andi Kleen 提交于 
      VT-x needs an explicit MC vector intercept to handle machine checks in the
hyper visor.

It also has a special option to catch machine checks that happen
during VT entry.

Do these interceptions and forward them to the Linux machine check
handler. Make it always look like user space is interrupted because
the machine check handler treats kernel/user space differently.

Thanks to Jiang Yunhong for help and testing.

Cc: stable@kernel.org
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      a0861c02
  9. 24 3月, 2009 2 次提交
    • J
      KVM: x86: Virtualize debug registers · 42dbaa5a
      由 Jan Kiszka 提交于 
      So far KVM only had basic x86 debug register support, once introduced to
realize guest debugging that way. The guest itself was not able to use
those registers.

This patch now adds (almost) full support for guest self-debugging via
hardware registers. It refactors the code, moving generic parts out of
SVM (VMX was already cleaned up by the KVM_SET_GUEST_DEBUG patches), and
it ensures that the registers are properly switched between host and
guest.

This patch also prepares debug register usage by the host. The latter
will (once wired-up by the following patch) allow for hardware
breakpoints/watchpoints in guest code. If this is enabled, the guest
will only see faked debug registers without functionality, but with
content reflecting the guest's modifications.

Tested on Intel only, but SVM /should/ work as well, but who knows...

Known limitations: Trapping on tss switch won't work - most probably on
Intel.

Credits also go to Joerg Roedel - I used his once posted debugging
series as platform for this patch.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      42dbaa5a
    • J
      KVM: VMX: Support for injecting software exceptions · 8ab2d2e2
      由 Jan Kiszka 提交于 
      VMX differentiates between processor and software generated exceptions
when injecting them into the guest. Extend vmx_queue_exception
accordingly (and refactor related constants) so that we can use this
service reliably for the new guest debugging framework.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      8ab2d2e2
  11. 31 12月, 2008 4 次提交
  13. 12 11月, 2008 1 次提交
    • S
      KVM: VMX: Set IGMT bit in EPT entry · 928d4bf7
      由 Sheng Yang 提交于 
      There is a potential issue that, when guest using pagetable without vmexit when
EPT enabled, guest would use PAT/PCD/PWT bits to index PAT msr for it's memory,
which would be inconsistent with host side and would cause host MCE due to
inconsistent cache attribute.

The patch set IGMT bit in EPT entry to ignore guest PAT and use WB as default
memory type to protect host (notice that all memory mapped by KVM should be WB).
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
      928d4bf7
  15. 15 10月, 2008 3 次提交
  17. 11 9月, 2008 1 次提交
  19. 10 9月, 2008 1 次提交
  21. 20 7月, 2008 1 次提交
  23. 04 5月, 2008 4 次提交
  25. 27 4月, 2008 2 次提交
  27. 31 1月, 2008 1 次提交
  29. 30 1月, 2008 5 次提交
  31. 13 10月, 2007 4 次提交
  33. 13 2月, 2007 1 次提交
  35. 31 12月, 2006 1 次提交
  37. 11 12月, 2006 1 次提交
    • A
      [PATCH] kvm: userspace interface · 6aa8b732
      由 Avi Kivity 提交于 
      web site: http://kvm.sourceforge.net

mailing list: kvm-devel@lists.sourceforge.net
  (http://lists.sourceforge.net/lists/listinfo/kvm-devel)

The following patchset adds a driver for Intel's hardware virtualization
extensions to the x86 architecture.  The driver adds a character device
(/dev/kvm) that exposes the virtualization capabilities to userspace.  Using
this driver, a process can run a virtual machine (a "guest") in a fully
virtualized PC containing its own virtual hard disks, network adapters, and
display.

Using this driver, one can start multiple virtual machines on a host.

Each virtual machine is a process on the host; a virtual cpu is a thread in
that process.  kill(1), nice(1), top(1) work as expected.  In effect, the
driver adds a third execution mode to the existing two: we now have kernel
mode, user mode, and guest mode.  Guest mode has its own address space mapping
guest physical memory (which is accessible to user mode by mmap()ing
/dev/kvm).  Guest mode has no access to any I/O devices; any such access is
intercepted and directed to user mode for emulation.

The driver supports i386 and x86_64 hosts and guests.  All combinations are
allowed except x86_64 guest on i386 host.  For i386 guests and hosts, both pae
and non-pae paging modes are supported.

SMP hosts and UP guests are supported.  At the moment only Intel
hardware is supported, but AMD virtualization support is being worked on.

Performance currently is non-stellar due to the naive implementation of the
mmu virtualization, which throws away most of the shadow page table entries
every context switch.  We plan to address this in two ways:

- cache shadow page tables across tlb flushes
- wait until AMD and Intel release processors with nested page tables

Currently a virtual desktop is responsive but consumes a lot of CPU.  Under
Windows I tried playing pinball and watching a few flash movies; with a recent
CPU one can hardly feel the virtualization.  Linux/X is slower, probably due
to X being in a separate process.

In addition to the driver, you need a slightly modified qemu to provide I/O
device emulation and the BIOS.

Caveats (akpm: might no longer be true):

- The Windows install currently bluescreens due to a problem with the
  virtual APIC.  We are working on a fix.  A temporary workaround is to
  use an existing image or install through qemu
- Windows 64-bit does not work.  That's also true for qemu, so it's
  probably a problem with the device model.

[bero@arklinux.org: build fix]
[simon.kagstrom@bth.se: build fix, other fixes]
[uril@qumranet.com: KVM: Expose interrupt bitmap]
[akpm@osdl.org: i386 build fix]
[mingo@elte.hu: i386 fixes]
[rdreier@cisco.com: add log levels to all printks]
[randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings]
[anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support]
Signed-off-by: NYaniv Kamay <yaniv@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Simon Kagstrom <simon.kagstrom@bth.se>
Cc: Bernhard Rosenkraenzer <bero@arklinux.org>
Signed-off-by: NUri Lublin <uril@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAnthony Liguori <anthony@codemonkey.ws>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      6aa8b732