Messages in this thread | | | Date | Wed, 8 May 2024 21:58:42 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v4 05/15] x86/sev: Use kernel provided SVSM Calling Areas |
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On Wed, May 08, 2024 at 02:13:17PM -0500, Tom Lendacky wrote: > ok, maybe __perform_svsm_msr_protocol or such.
We'll bikeshed it in the coming weeks.
> There's quite a bit of interaction so I'll make sure to prefix everything.
Ack.
> The paravirt versions of local_irq_save and local_irq_restore can't be used > as early as this routine is called.
tglx says you should do native_local_irq_save()/.._restore() helpers just like the arch_local_irq_save()/..._restore() ones but use only native_ functions without the paravirt gunk.
In a prepatch pls.
> > > + struct svsm_call call = {}; > > > + int ret; > > > + u64 pa; > > > + > > > + /* > > > + * Record the SVSM Calling Area address (CAA) if the guest is not > > > + * running at VMPL0. The CA will be used to communicate with the > > > + * SVSM to perform the SVSM services. > > > + */ > > > + setup_svsm_ca(cc_info); > > > + > > > + /* Nothing to do if not running under an SVSM. */ > > > + if (!vmpl) > > > + return; > > > > You set up stuff above and now you bail out? > > setup_svsm_ca() is what sets the vmpl variable. So nothing will have been > setup if the VMPL is zero, in which case we don't continue on.
You still assign
/* * The CA is identity mapped when this routine is called, both by the * decompressor code and the early kernel code. */ boot_svsm_caa = (struct svsm_ca *)caa; boot_svsm_caa_pa = caa;
regardless of vmpl.
I think you should assign those only when vmpl != 0.
Otherwise the code is confusing.
> > Judging by setup_svsm_ca() you don't really need that vmpl var but you > > can check > > > > if (!boot_svsm_caa) > > return; > > > > to determine whether a SVSM was detected. > > Yes, but the vmpl var will be used for attestation requests, sysfs, etc.
I guess that comes later in the patchset...
> > Huh, setup_svsm_ca() already assigned those... > > setup_svsm_ca() assigned the ones from the secrets page. The kernel now > switches to using its own CA.
Comment pls.
Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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