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    7a5235c9
    hax: Support guest RAM sizes of 4GB or more · 7a5235c9
    Yu Ning authored
    Since HAX_VM_IOCTL_ALLOC_RAM takes a 32-bit size, it cannot handle
    RAM blocks of 4GB or larger, which is why HAXM can only run guests
    with less than 4GB of RAM. Solve this problem by utilizing the new
    HAXM API, HAX_VM_IOCTL_ADD_RAMBLOCK, which takes a 64-bit size, to
    register RAM blocks with the HAXM kernel module. The new API is
    first added in HAXM 7.0.0, and its availablility and be confirmed
    by the presence of the HAX_CAP_64BIT_RAMBLOCK capability flag.
    
    When the guest RAM size reaches 7GB, QEMU will ask HAXM to set up a
    memory mapping that covers a 4GB region, which will fail, because
    HAX_VM_IOCTL_SET_RAM also takes a 32-bit size. Work around this
    limitation by splitting the large mapping into small ones and
    calling HAX_VM_IOCTL_SET_RAM multiple times.
    
    Bug: https://bugs.launchpad.net/qemu/+bug/1735576
    
    
    
    Signed-off-by: default avatarYu Ning <yu.ning@intel.com>
    Message-Id: <1515752555-12784-1-git-send-email-yu.ning@linux.intel.com>
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    7a5235c9
    History
    hax: Support guest RAM sizes of 4GB or more
    Yu Ning authored
    Since HAX_VM_IOCTL_ALLOC_RAM takes a 32-bit size, it cannot handle
    RAM blocks of 4GB or larger, which is why HAXM can only run guests
    with less than 4GB of RAM. Solve this problem by utilizing the new
    HAXM API, HAX_VM_IOCTL_ADD_RAMBLOCK, which takes a 64-bit size, to
    register RAM blocks with the HAXM kernel module. The new API is
    first added in HAXM 7.0.0, and its availablility and be confirmed
    by the presence of the HAX_CAP_64BIT_RAMBLOCK capability flag.
    
    When the guest RAM size reaches 7GB, QEMU will ask HAXM to set up a
    memory mapping that covers a 4GB region, which will fail, because
    HAX_VM_IOCTL_SET_RAM also takes a 32-bit size. Work around this
    limitation by splitting the large mapping into small ones and
    calling HAX_VM_IOCTL_SET_RAM multiple times.
    
    Bug: https://bugs.launchpad.net/qemu/+bug/1735576
    
    
    
    Signed-off-by: default avatarYu Ning <yu.ning@intel.com>
    Message-Id: <1515752555-12784-1-git-send-email-yu.ning@linux.intel.com>
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>