From: Borislav Petkov <bp@alien8.de>
To: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Cc: Michael Roth <michael.roth@amd.com>,
x86@kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev,
linux-mm@kvack.org, linux-crypto@vger.kernel.org,
linux-kernel@vger.kernel.org, tglx@linutronix.de,
mingo@redhat.com, jroedel@suse.de, thomas.lendacky@amd.com,
hpa@zytor.com, ardb@kernel.org, pbonzini@redhat.com,
seanjc@google.com, vkuznets@redhat.com, jmattson@google.com,
luto@kernel.org, dave.hansen@linux.intel.com, slp@redhat.com,
pgonda@google.com, peterz@infradead.org,
srinivas.pandruvada@linux.intel.com, rientjes@google.com,
tobin@ibm.com, vbabka@suse.cz, kirill@shutemov.name,
ak@linux.intel.com, tony.luck@intel.com,
sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com,
jarkko@kernel.org, ashish.kalra@amd.com, nikunj.dadhania@amd.com,
pankaj.gupta@amd.com, liam.merwick@oracle.com,
zhi.a.wang@intel.com, Brijesh Singh <brijesh.singh@amd.com>
Subject: Re: [PATCH v1 04/26] x86/sev: Add the host SEV-SNP initialization support
Date: Fri, 5 Jan 2024 17:21:42 +0100 [thread overview]
Message-ID: <20240105162142.GEZZgslgQCQYI7twat@fat_crate.local> (raw)
In-Reply-To: <20240105160916.GDZZgprE8T6xbbHJ9E@fat_crate.local>
On Fri, Jan 05, 2024 at 05:09:16PM +0100, Borislav Petkov wrote:
> On Thu, Jan 04, 2024 at 12:05:27PM +0100, Jeremi Piotrowski wrote:
> > Is there a really good reason to perform the snp_probe_smptable_info() check at this
> > point (instead of in snp_rmptable_init). snp_rmptable_init will also clear the cap
> > on failure, and bsp_init_amd() runs too early to allow for the kernel to allocate the
> > rmptable itself. I pointed out in the previous review that kernel allocation of rmptable
> > is necessary in SNP-host capable VMs in Azure.
>
> What does that even mean?
>
> That function is doing some calculations after reading two MSRs. What
> can possibly go wrong?!
That could be one reason perhaps:
"It needs to be called early enough to allow for AutoIBRS to not be disabled
just because SNP is supported. By calling it where it is currently called, the
SNP feature can be cleared if, even though supported, SNP can't be used,
allowing AutoIBRS to be used as a more performant Spectre mitigation."
https://lore.kernel.org/r/8ec38db1-5ccf-4684-bc0d-d48579ebf0d0@amd.com
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2024-01-05 16:22 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-30 16:19 [PATCH v1 00/26] Add AMD Secure Nested Paging (SEV-SNP) Initialization Support Michael Roth
2023-12-30 16:19 ` [PATCH v1 01/26] x86/cpufeatures: Add SEV-SNP CPU feature Michael Roth
2023-12-31 11:50 ` Borislav Petkov
2023-12-31 16:44 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 02/26] x86/speculation: Do not enable Automatic IBRS if SEV SNP is enabled Michael Roth
2023-12-30 16:19 ` [PATCH v1 03/26] iommu/amd: Don't rely on external callers to enable IOMMU SNP support Michael Roth
2024-01-04 10:30 ` Borislav Petkov
2024-01-04 10:58 ` Joerg Roedel
2023-12-30 16:19 ` [PATCH v1 04/26] x86/sev: Add the host SEV-SNP initialization support Michael Roth
2024-01-04 11:05 ` Jeremi Piotrowski
2024-01-05 16:09 ` Borislav Petkov
2024-01-05 16:21 ` Borislav Petkov [this message]
2024-01-08 16:49 ` Jeremi Piotrowski
2024-01-08 17:04 ` Borislav Petkov
2024-01-09 11:56 ` Jeremi Piotrowski
2024-01-09 12:29 ` Borislav Petkov
2024-01-09 12:44 ` Borislav Petkov
2024-02-14 16:56 ` Jeremi Piotrowski
2024-01-04 11:16 ` Borislav Petkov
2024-01-04 14:42 ` Borislav Petkov
2024-01-05 19:19 ` Borislav Petkov
2024-01-05 21:27 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 05/26] x86/mtrr: Don't print errors if MtrrFixDramModEn is set when SNP enabled Michael Roth
2023-12-30 16:19 ` [PATCH v1 06/26] x86/sev: Add RMP entry lookup helpers Michael Roth
2023-12-30 16:19 ` [PATCH v1 07/26] x86/fault: Add helper for dumping RMP entries Michael Roth
2024-01-10 9:59 ` Borislav Petkov
2024-01-10 20:18 ` Jarkko Sakkinen
2024-01-10 22:14 ` Borislav Petkov
2024-01-10 11:13 ` Borislav Petkov
2024-01-10 15:20 ` Tom Lendacky
2024-01-10 15:27 ` Borislav Petkov
2024-01-10 15:51 ` Tom Lendacky
2024-01-10 15:55 ` Borislav Petkov
2024-01-10 15:10 ` Tom Lendacky
2023-12-30 16:19 ` [PATCH v1 08/26] x86/traps: Define RMP violation #PF error code Michael Roth
2023-12-30 16:19 ` [PATCH v1 09/26] x86/fault: Dump RMP table information when RMP page faults occur Michael Roth
2023-12-30 16:19 ` [PATCH v1 10/26] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction Michael Roth
2024-01-12 14:49 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 11/26] x86/sev: Invalidate pages from the direct map when adding them to the RMP table Michael Roth
2024-01-12 19:48 ` Borislav Petkov
2024-01-12 20:00 ` Dave Hansen
2024-01-12 20:07 ` Borislav Petkov
2024-01-12 20:27 ` Vlastimil Babka
2024-01-15 9:06 ` Borislav Petkov
2024-01-15 9:14 ` Vlastimil Babka
2024-01-15 9:16 ` Mike Rapoport
2024-01-15 9:20 ` Borislav Petkov
2024-01-12 20:28 ` Tom Lendacky
2024-01-12 20:37 ` Dave Hansen
2024-01-15 9:23 ` Vlastimil Babka
2024-01-16 16:19 ` Michael Roth
2024-01-16 16:50 ` Michael Roth
2024-01-16 20:12 ` Mike Rapoport
2024-01-26 1:49 ` Michael Roth
2024-01-16 18:22 ` Borislav Petkov
2024-01-16 20:22 ` Dave Hansen
2024-01-26 1:35 ` Michael Roth
2024-01-15 9:09 ` Borislav Petkov
2024-01-16 16:21 ` Dave Hansen
2024-01-17 9:34 ` Borislav Petkov
2024-01-15 9:01 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 12/26] crypto: ccp: Define the SEV-SNP commands Michael Roth
2024-01-15 9:41 ` Borislav Petkov
2024-01-26 1:56 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 13/26] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP Michael Roth
2024-01-15 11:19 ` Borislav Petkov
2024-01-15 19:53 ` Borislav Petkov
2024-01-26 2:48 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 14/26] crypto: ccp: Provide API to issue SEV and SNP commands Michael Roth
2024-01-17 9:48 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 15/26] x86/sev: Introduce snp leaked pages list Michael Roth
2024-01-08 10:45 ` Vlastimil Babka
2024-01-09 22:19 ` Kalra, Ashish
2024-01-10 8:59 ` Vlastimil Babka
2023-12-30 16:19 ` [PATCH v1 16/26] crypto: ccp: Handle the legacy TMR allocation when SNP is enabled Michael Roth
2023-12-30 16:19 ` [PATCH v1 17/26] crypto: ccp: Handle non-volatile INIT_EX data " Michael Roth
2024-01-18 14:03 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 18/26] crypto: ccp: Handle legacy SEV commands " Michael Roth
2024-01-19 17:18 ` Borislav Petkov
2024-01-19 17:36 ` Tom Lendacky
2024-01-19 17:48 ` Borislav Petkov
2024-01-26 13:29 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 19/26] iommu/amd: Clean up RMP entries for IOMMU pages during SNP shutdown Michael Roth
2023-12-30 16:19 ` [PATCH v1 20/26] crypto: ccp: Add debug support for decrypting pages Michael Roth
2024-01-10 14:59 ` Sean Christopherson
2024-01-11 0:50 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 21/26] crypto: ccp: Add panic notifier for SEV/SNP firmware shutdown on kdump Michael Roth
2024-01-21 11:49 ` Borislav Petkov
2024-01-26 3:03 ` Kalra, Ashish
2024-01-26 13:38 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 22/26] KVM: SEV: Make AVIC backing, VMSA and VMCB memory allocation SNP safe Michael Roth
2024-01-21 11:51 ` Borislav Petkov
2024-01-26 3:44 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 23/26] x86/cpufeatures: Enable/unmask SEV-SNP CPU feature Michael Roth
2023-12-30 16:19 ` [PATCH v1 24/26] crypto: ccp: Add the SNP_PLATFORM_STATUS command Michael Roth
2024-01-21 12:29 ` Borislav Petkov
2024-01-26 3:32 ` Michael Roth
2023-12-30 16:19 ` [PATCH v1 25/26] crypto: ccp: Add the SNP_COMMIT command Michael Roth
2024-01-21 12:35 ` Borislav Petkov
2023-12-30 16:19 ` [PATCH v1 26/26] crypto: ccp: Add the SNP_SET_CONFIG command Michael Roth
2024-01-21 12:41 ` Borislav Petkov
2024-01-26 13:30 ` Michael Roth
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