linux-user: Speed up guest space initialization on 32-bit ARM target

[Qemu-devel] [PATCH 00/10] linux-user: Speed up guest space initialization on 32-bit ARM target

Posted by Luke Shumaker 7 years, 10 months ago

From: Luke Shumaker <lukeshu@parabola.nu>

The goal of this patchset is to fix
https://bugs.launchpad.net/qemu/+bug/1740219

The gist is that the current linear search for an acceptable address
range is a bad strategy when the reason we didn't get a good address
on the first try is that we've having problems mapping the commpage
for the 32-bit ARM target; especially if ASLR is disabled.

I think that only the final patch in this patchset is actually
necessary to fix the issue; but I didn't feel comfortable writing it
without also makeing the preceding (small) changes.

Luke Shumaker (10):
  linux-user: Use #if to only call validate_guest_space for 32-bit ARM
    target
  linux-user: Rename validate_guest_space => init_guest_commpage
  linux-user: init_guest_space: Clean up if we can't initialize the
    commpage
  linux-user: init_guest_space: Correctly handle guest_start in commpage
    initialization
  linux-user: init_guest_space: Clarify page alignment logic
  linux-user: init_guest_commpage: Add a comment about size check
  linux-user: init_guest_space: Clean up control flow a bit
  linux-user: init_guest_space: Don't try to align if we'll reject it
  linux-user: init_guest_space: Add a comment about search strategy
  linux-user: init_guest_space: Try to make ARM space+commpage
    continuous

 linux-user/elfload.c | 145 ++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 114 insertions(+), 31 deletions(-)

-- 
2.15.1

Happy hacking,
~ Luke Shumaker

Re: [Qemu-devel] [PATCH 00/10] linux-user: Speed up guest space initialization on 32-bit ARM target

Posted by Luke Shumaker 7 years, 9 months ago

Ping for code review?

-- 
Happy hacking,
~ Luke Shumaker

Re: [Qemu-devel] [PATCH 00/10] linux-user: Speed up guest space initialization on 32-bit ARM target

Posted by Luke Shumaker 7 years, 8 months ago

Ping.

On Thu, 28 Dec 2017 13:08:03 -0500,
Luke Shumaker wrote:
> 
> From: Luke Shumaker <lukeshu@parabola.nu>
> 
> The goal of this patchset is to fix
> https://bugs.launchpad.net/qemu/+bug/1740219
> 
> The gist is that the current linear search for an acceptable address
> range is a bad strategy when the reason we didn't get a good address
> on the first try is that we've having problems mapping the commpage
> for the 32-bit ARM target; especially if ASLR is disabled.
> 
> I think that only the final patch in this patchset is actually
> necessary to fix the issue; but I didn't feel comfortable writing it
> without also makeing the preceding (small) changes.
> 
> Luke Shumaker (10):
>   linux-user: Use #if to only call validate_guest_space for 32-bit ARM
>     target
>   linux-user: Rename validate_guest_space => init_guest_commpage
>   linux-user: init_guest_space: Clean up if we can't initialize the
>     commpage
>   linux-user: init_guest_space: Correctly handle guest_start in commpage
>     initialization
>   linux-user: init_guest_space: Clarify page alignment logic
>   linux-user: init_guest_commpage: Add a comment about size check
>   linux-user: init_guest_space: Clean up control flow a bit
>   linux-user: init_guest_space: Don't try to align if we'll reject it
>   linux-user: init_guest_space: Add a comment about search strategy
>   linux-user: init_guest_space: Try to make ARM space+commpage
>     continuous
> 
>  linux-user/elfload.c | 145 ++++++++++++++++++++++++++++++++++++++++-----------
>  1 file changed, 114 insertions(+), 31 deletions(-)
> 
> -- 
> 2.15.1
> 
> Happy hacking,
> ~ Luke Shumaker
>