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Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Borislav Petkov , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , Tony Luck , Marc Orr , Sathyanarayanan Kuppuswamy , Alper Gun , "Dr. David Alan Gilbert" , jarkko@kernel.org Content-Type: text/plain; charset="UTF-8" ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Fi5EjLIz; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf24.hostedemail.com: domain of pgonda@google.com designates 209.85.208.182 as permitted sender) smtp.mailfrom=pgonda@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655825298; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=PPDc7qXBrAf8hM+ois/4M7n9y0Ctx2nTK0cCddntA00=; b=tI9ucGFoCdMj3h8JeDuH4lFSNf/jFDmq+TwZMSRE3hG7Iif6j+JH+k0VZZgwc3TBwgIGlS ArRaM3omXVQn4/NPc3QRLLPwltCqaKNhQtRGBdr5WJ3cnXVIVEUcS19GvJf3V7vfTy8V+u NTbCKuY4DFqZtsV+bxZ+yVlim0z2SbY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1655825298; a=rsa-sha256; cv=none; b=AAnJiqrMKniHeHtZIKuYnvDbjzKScnYJLRYEopvUCksVUUVDWEhK2ExHad9hHUFtmMHm9v QAiO4o5QIqwfdTRVh7uKZytmhV9JGHam6SxwMty48/JmHVPs0s1DQy0wKo4lDdC88QOWjR vgLLO7F2Xuv8wO8RTK1sJza6k72jyyg= X-Rspamd-Queue-Id: 6E1DB180009 Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Fi5EjLIz; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf24.hostedemail.com: domain of pgonda@google.com designates 209.85.208.182 as permitted sender) smtp.mailfrom=pgonda@google.com X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: 83g8xu7k9d8zsoq58pynbptni7g7bzec X-HE-Tag: 1655825298-484122 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Jun 20, 2022 at 4:59 PM Ashish Kalra wrote: > > From: Brijesh Singh > > The SEV-SNP support requires that IOMMU must to enabled, see the IOMMU > spec section 2.12 for further details. If IOMMU is not enabled or the > SNPSup extended feature register is not set then the SNP_INIT command > (used for initializing firmware) will fail. > > The iommu_sev_snp_supported() can be used to check if IOMMU supports the > SEV-SNP feature. > > Signed-off-by: Brijesh Singh > --- > drivers/iommu/amd/init.c | 30 ++++++++++++++++++++++++++++++ > include/linux/iommu.h | 9 +++++++++ > 2 files changed, 39 insertions(+) > > diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c > index 1a3ad58ba846..82be8067ddf5 100644 > --- a/drivers/iommu/amd/init.c > +++ b/drivers/iommu/amd/init.c > @@ -3361,3 +3361,33 @@ int amd_iommu_pc_set_reg(struct amd_iommu *iommu, u8 bank, u8 cntr, u8 fxn, u64 > > return iommu_pc_get_set_reg(iommu, bank, cntr, fxn, value, true); > } > + > +bool iommu_sev_snp_supported(void) > +{ > + struct amd_iommu *iommu; > + > + /* > + * The SEV-SNP support requires that IOMMU must be enabled, and is > + * not configured in the passthrough mode. > + */ > + if (no_iommu || iommu_default_passthrough()) { > + pr_err("SEV-SNP: IOMMU is either disabled or configured in passthrough mode.\n"); Like below could this say something like snp support is disabled because of iommu settings. > + return false; > + } > + > + /* > + * Iterate through all the IOMMUs and verify the SNPSup feature is > + * enabled. > + */ > + for_each_iommu(iommu) { > + if (!iommu_feature(iommu, FEATURE_SNP)) { > + pr_err("SNPSup is disabled (devid: %02x:%02x.%x)\n", SNPSup might not be obvious to readers, what about " SNP Support is disabled ...". Also should this have the "SEV-SNP:" prefix like the above log? > + PCI_BUS_NUM(iommu->devid), PCI_SLOT(iommu->devid), > + PCI_FUNC(iommu->devid)); > + return false; > + } > + } > + > + return true; > +} > +EXPORT_SYMBOL_GPL(iommu_sev_snp_supported); > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 9208eca4b0d1..fecb72e1b11b 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -675,6 +675,12 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, > void iommu_sva_unbind_device(struct iommu_sva *handle); > u32 iommu_sva_get_pasid(struct iommu_sva *handle); > > +#ifdef CONFIG_AMD_MEM_ENCRYPT > +bool iommu_sev_snp_supported(void); > +#else > +static inline bool iommu_sev_snp_supported(void) { return false; } > +#endif > + > #else /* CONFIG_IOMMU_API */ > > struct iommu_ops {}; > @@ -1031,6 +1037,9 @@ static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev) > { > return NULL; > } > + > +static inline bool iommu_sev_snp_supported(void) { return false; } > + > #endif /* CONFIG_IOMMU_API */ > > /** > -- > 2.25.1 >