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Re: [Qemu-devel] [PATCH v3] ivshmem: Fix 64 bit memory bar configuration
From: |
Markus Armbruster |
Subject: |
Re: [Qemu-devel] [PATCH v3] ivshmem: Fix 64 bit memory bar configuration |
Date: |
Thu, 17 Nov 2016 14:27:50 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) |
Zhuangyanying <address@hidden> writes:
> From: Zhuang Yanying <address@hidden>
>
> Device ivshmem property use64=0 is designed to make the device
> expose a 32 bit shared memory BAR instead of 64 bit one. The
> default is a 64 bit BAR, except pc-1.2 and older retain a 32 bit
> BAR. A 32 bit BAR can support only up to 1 GiB of shared memory.
>
> This worked as designed until commit 5400c02 accidentally flipped
> its sense: since then, we misinterpret use64=0 as use64=1 and vice
> versa. Worse, the default got flipped as well. Devices
> ivshmem-plain and ivshmem-doorbell are not affected.
>
> Fix by restoring the test of IVShmemState member not_legacy_32bit
> that got messed up in commit 5400c02. Also update its
> initialization for devices ivhsmem-plain and ivshmem-doorbell.
> Without that, they'd regress to 32 bit BARs.
>
> Cc: address@hidden
> Signed-off-by: Zhuang Yanying <address@hidden>
> Reviewed-by: Gonglei <address@hidden>
> Reviewed-by: Marc-Andr. Lureau <address@hidden>
Commit message should not be indented, and Marc-André's name got
mangled. Both could be touched up on commit.
Thanks again for cleaning up my mess.
Reviewed-by: Markus Armbruster <address@hidden>