[libvirt] [PATCH 2/2] qemu: Remove host-passthrough validation check for host-phys-bits=on

[Claudio Fontana]

On 8/17/22 10:19, Lin Ma wrote:
> Besides the -cpu host, The host-phys-bits=on applies to custom or max
> cpu model, So the host-passthrough validation check is unnecessary for
> maxphysaddr with mode='passthrough'.
> 
> Signed-off-by: Lin Ma <lma at suse.com>
> ---
>  src/qemu/qemu_validate.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
> index 6e457f3814..e60575d8a0 100644
> --- a/src/qemu/qemu_validate.c
> +++ b/src/qemu/qemu_validate.c
> @@ -344,13 +344,6 @@ qemuValidateDomainDefCpu(virQEMUDriver *driver,
>  
>          switch (addr->mode) {
>          case VIR_CPU_MAX_PHYS_ADDR_MODE_PASSTHROUGH:
> -            if (def->cpu->mode != VIR_CPU_MODE_HOST_PASSTHROUGH) {
> -                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> -                               _("CPU maximum physical address bits mode '%s' can only be used with '%s' CPUs"),
> -                               virCPUMaxPhysAddrModeTypeToString(addr->mode),
> -                               virCPUModeTypeToString(VIR_CPU_MODE_HOST_PASSTHROUGH));
> -                return -1;
> -            }
>              if (addr->bits != -1) {
>                  virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>                                 _("CPU maximum physical address bits number specification cannot be used with mode='%s'"),

Hmm what was the reason for this, maybe Dario knows?

In my view we definitely do not want to restrict this to VIR_CPU_MODE_HOST_PASSTHROUGH only,
but this should be restricted in my view to QEMU hw accelerators that use host cpuid (as per accel_uses_host_cpuid() -> true),
which are KVM and HVF.

Not sure how to properly check that?

Ciao,

CLaudio