Re: [PATCH] x86/shim: Simplify compat handling in write_start_info()

2021-04-20 Thread Andrew Cooper
On 19/04/2021 17:00, Jan Beulich wrote: > On 19.04.2021 17:57, Andrew Cooper wrote: >> On 19/04/2021 16:55, Jan Beulich wrote: >>> On 19.04.2021 16:45, Andrew Cooper wrote: Factor out a compat boolean to remove the lfence overhead from multiple is_pv_32bit_domain() calls. For a

Re: [PATCH] x86/shim: Simplify compat handling in write_start_info()

2021-04-19 Thread Jan Beulich
On 19.04.2021 17:57, Andrew Cooper wrote: > On 19/04/2021 16:55, Jan Beulich wrote: >> On 19.04.2021 16:45, Andrew Cooper wrote: >>> Factor out a compat boolean to remove the lfence overhead from multiple >>> is_pv_32bit_domain() calls. >>> >>> For a compat guest, the upper 32 bits of rdx are

Re: [PATCH] x86/shim: Simplify compat handling in write_start_info()

2021-04-19 Thread Andrew Cooper
On 19/04/2021 16:55, Jan Beulich wrote: > On 19.04.2021 16:45, Andrew Cooper wrote: >> Factor out a compat boolean to remove the lfence overhead from multiple >> is_pv_32bit_domain() calls. >> >> For a compat guest, the upper 32 bits of rdx are zero, so there is no need to >> have any conditional

Re: [PATCH] x86/shim: Simplify compat handling in write_start_info()

2021-04-19 Thread Jan Beulich
On 19.04.2021 16:45, Andrew Cooper wrote: > Factor out a compat boolean to remove the lfence overhead from multiple > is_pv_32bit_domain() calls. > > For a compat guest, the upper 32 bits of rdx are zero, so there is no need to > have any conditional logic at all when mapping the start info page.

[PATCH] x86/shim: Simplify compat handling in write_start_info()

2021-04-19 Thread Andrew Cooper
Factor out a compat boolean to remove the lfence overhead from multiple is_pv_32bit_domain() calls. For a compat guest, the upper 32 bits of rdx are zero, so there is no need to have any conditional logic at all when mapping the start info page. Signed-off-by: Andrew Cooper --- CC: Jan Beulich