Re: [libvirt] [PATCH 2/2] qemu: Remove host-passthrough validation check for host-phys-bits=on
On 8/17/22 08:47, Jim Fehlig wrote:
On 8/17/22 02:19, 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'.
I wonder why Dario added the check? He even added a test for it:
cpu-phys-bits-passthrough2 in qemuxml2argvtest. He is off now, so we'll have to
await his return for an answer.
BTW, I'm not doubting your analysis. In fact, I tested with one of the known CPU
models (-cpu Cascadelake-Server,...,host-phys-bits=on) and it worked fine with a
7TB VM. I'd still like to know why Dario added the check. Perhaps he encountered
some problematic corner cases.
Thanks!
Jim
> Signed-off-by: Lin Ma <lma(a)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 the check is removed the above mentioned test needs removed too.
Regards,
Jim
> if (addr->bits != -1) {
> virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> _("CPU maximum physical address bits number
> specification cannot be used with mode='%s'"),