Re: [PATCH v3 05/13] xen: generate hypercall interface related code

[Jan Beulich <jbeulich@suse.com>]

On 08.12.2021 16:55, Juergen Gross wrote:
> Instead of repeating similar data multiple times use a single source
> file and a generator script for producing prototypes and call sequences
> of the hypercalls.
> 
> As the script already knows the number of parameters used add generating
> a macro for populating an array with the number of parameters per
> hypercall.
> 
> The priorities for the specific hypercalls are based on two benchamrks
> performed in guests (PV and PVH):
> 
> - make -j 4 of the Xen hypervisor (resulting in cpu load with lots of
>   processes created)
> - scp of a large file to the guest (network load)
> 
> With a small additional debug patch applied the number of the
> different hypercalls in the guest and in dom0 (for looking at backend
> activity related hypercalls) were counted while the benchmark in domU
> was running:
> 
> PV-hypercall    PV-guest build   PV-guest scp    dom0 build     dom0 scp
> mmu_update           186175729           2865         20936        33725
> stack_switch           1273311          62381        108589       270764
> multicall              2182803             50           302          524
> update_va_mapping       571868             10            60           80
> xen_version              73061            850           859         5432
> grant_table_op               0              0         35557       139110
> iret                  75673006         484132        268157       757958
> vcpu_op                 453037          71199        138224       334988
> set_segment_base       1650249          62387        108645       270823
> mmuext_op             11225681            188          7239         3426
> sched_op                280153         134645         70729       137943
> event_channel_op        192327          66204         71409       214191
> physdev_op                   0              0          7721         4315
> (the dom0 values are for the guest running the build or scp test, so
> dom0 acting as backend)
> 
> HVM-hypercall   PVH-guest build    PVH-guest scp
> vcpu_op                  277684             2324
> event_channel_op         350233            57383
> (the related dom0 counter values are in the same range as with the test
> running in the PV guest)
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>