Re: [PATCH v2 00/10] kvm: memory slot cleanups, fix, and increase

[Gleb Natapov <gleb@redhat.com>]

On Mon, Dec 10, 2012 at 10:32:39AM -0700, Alex Williamson wrote:
> v2: Update 02/10 to not check userspace_addr when slot is removed.
>     Yoshikawa-san withdrew objection to increase slot_bitmap prior
>     to his series to remove slot_bitmap.
> 
> This series does away with any kind of complicated resizing of the
> slot array and simply does a one time increase.  I do compact struct
> kvm_memory_slot a bit to take better advantage of the space we are
> using.  This reduces each slot from 64 bytes (x86_64) to 56 bytes.
> By enforcing the API around valid operations for an unused slot and
> fields that can be modified runtime, I found and was able to fix a
> bug in iommu mapping for slots.  The renames enabled me to find the
> previously posted bug fix for catching slot overlaps.
> 
> As mentioned in the series, the primary motivation for increasing
> memory slots is assigned devices.  With this, I've been able to
> assign 30 devices to a single VM and could have gone further, but
> ran out of SRIOV VFs.  Typical devices use anywhere from 2-4 slots
> and max out at 8 slots.  125 user slots (3 private slots) allows
> us to support between 28 and 56 typical devices per VM.
> 
> Tested on x86_64, compiled on ia64, powerpc, and s390.
> 
> Thanks,
> Alex
> 
Reviewed-by: Gleb Natapov <gleb@redhat.com>

> ---
> 
> Alex Williamson (10):
>       kvm: Restrict non-existing slot state transitions
>       kvm: Check userspace_addr when modifying a memory slot
>       kvm: Fix iommu map/unmap to handle memory slot moves
>       kvm: Minor memory slot optimization
>       kvm: Rename KVM_MEMORY_SLOTS -> KVM_USER_MEM_SLOTS
>       kvm: Make KVM_PRIVATE_MEM_SLOTS optional
>       kvm: struct kvm_memory_slot.user_alloc -> bool
>       kvm: struct kvm_memory_slot.flags -> u32
>       kvm: struct kvm_memory_slot.id -> short
>       kvm: Increase user memory slots on x86 to 125
> 
> 
>  arch/ia64/include/asm/kvm_host.h    |    4 --
>  arch/ia64/kvm/kvm-ia64.c            |    8 ++--
>  arch/powerpc/include/asm/kvm_host.h |    6 +--
>  arch/powerpc/kvm/book3s_hv.c        |    2 -
>  arch/powerpc/kvm/powerpc.c          |    4 +-
>  arch/s390/include/asm/kvm_host.h    |    4 --
>  arch/s390/kvm/kvm-s390.c            |    4 +-
>  arch/x86/include/asm/kvm_host.h     |    8 ++--
>  arch/x86/include/asm/vmx.h          |    6 +--
>  arch/x86/kvm/vmx.c                  |    6 +--
>  arch/x86/kvm/x86.c                  |   10 ++---
>  include/linux/kvm_host.h            |   24 +++++++-----
>  virt/kvm/kvm_main.c                 |   72 +++++++++++++++++++++++------------
>  13 files changed, 90 insertions(+), 68 deletions(-)

--
			Gleb.