1. 22 Jul, 2007 1 commit
  2. 19 Jul, 2007 1 commit
    • Avi Kivity's avatar
      i386: Allow KVM on i386 nonpae · 2d9ce177
      Avi Kivity authored
      
      
      Currently, CONFIG_X86_CMPXCHG64 both enables boot-time checking of
      the cmpxchg64b feature and enables compilation of the set_64bit() family.
      Since the option is dependent on PAE, and since KVM depends on set_64bit(),
      this effectively disables KVM on i386 nopae.
      
      Simplify by removing the config option altogether: the boot check is made
      dependent on CONFIG_X86_PAE directly, and the set_64bit() family is exposed
      without constraints.  It is up to users to check for the feature flag (KVM
      does not as virtualiation extensions imply its existence).
      Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2d9ce177
  3. 16 Jul, 2007 2 commits
  4. 10 May, 2007 1 commit
  5. 13 Dec, 2006 1 commit
  6. 10 Dec, 2006 1 commit
    • Avi Kivity's avatar
      [PATCH] kvm: userspace interface · 6aa8b732
      Avi Kivity authored
      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: default avatarYaniv Kamay <yaniv@qumranet.com>
      Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
      Cc: Simon Kagstrom <simon.kagstrom@bth.se>
      Cc: Bernhard Rosenkraenzer <bero@arklinux.org>
      Signed-off-by: default avatarUri Lublin <uril@qumranet.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Roland Dreier <rolandd@cisco.com>
      Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: default avatarAnthony Liguori <anthony@codemonkey.ws>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      6aa8b732