1. 23 9月, 2016 8 次提交
  2. 22 9月, 2016 25 次提交
  3. 20 9月, 2016 3 次提交
  4. 16 9月, 2016 2 次提交
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      a41d87f4
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      qemu: map "virtio" video model to "virt" machtype correctly (arm/aarch64) · 706b5b62
      Laszlo Ersek 提交于
      Most of QEMU's PCI display device models, such as:
      
        libvirt video/model/@type  QEMU -device
        -------------------------  ------------
        cirrus                     cirrus-vga
        vga                        VGA
        qxl                        qxl-vga
        virtio                     virtio-vga
      
      come with a linear framebuffer (sometimes called "VGA compatibility
      framebuffer"). This linear framebuffer lives in one of the PCI device's
      MMIO BARs, and allows guest code (primarily: firmware drivers, and
      non-accelerated OS drivers) to display graphics with direct memory access.
      
      Due to architectural reasons on aarch64/KVM hosts, this kind of
      framebuffer doesn't / can't work in
      
        qemu-system-(arm|aarch64) -M virt
      
      machines. Cache coherency issues guarantee a corrupted / unusable display.
      The problem has been researched by several people, including kvm-arm
      maintainers, and it's been decided that the best way (practically the only
      way) to have boot time graphics for such guests is to consolidate on
      QEMU's "virtio-gpu-pci" device.
      
      >From <https://bugzilla.redhat.com/show_bug.cgi?id=1195176>, libvirt
      supports
      
        <devices>
          <video>
            <model type='virtio'/>
          </video>
        </devices>
      
      but libvirt unconditionally maps @type='virtio' to QEMU's "virtio-vga"
      device model. (See the qemuBuildDeviceVideoStr() function and the
      "qemuDeviceVideo" enum impl.)
      
      According to the above, this is not right for the "virt" machine type; the
      qemu-system-(arm|aarch64) binaries don't even recognize the "virtio-vga"
      device model (justifiedly). Whereas "virtio-gpu-pci", which is a pure
      virtio device without a compatibility framebuffer, is available, and works
      fine.
      
      (The ArmVirtQemu ("AAVMF") platform of edk2 -- that is, the UEFI firmware
      for "virt" -- supports "virtio-gpu-pci", as of upstream commit
      3ef3209d3028. See
      <https://tianocore.acgmultimedia.com/show_bug.cgi?id=66>.)
      
      Override the default mapping of "virtio", from "virtio-vga" to
      "virtio-gpu-pci", if qemuDomainMachineIsVirt() evaluates to true.
      
      Cc: Andrea Bolognani <abologna@redhat.com>
      Cc: Drew Jones <drjones@redhat.com>
      Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
      Cc: Martin Kletzander <mkletzan@redhat.com>
      Suggested-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
      Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1372901Signed-off-by: NLaszlo Ersek <lersek@redhat.com>
      Acked-by: NMartin Kletzander <mkletzan@redhat.com>
      706b5b62
  5. 15 9月, 2016 1 次提交
  6. 14 9月, 2016 1 次提交