From: Borislav Petkov <bp@alien8.de>
To: Michael Roth <michael.roth@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, linux-efi@vger.kernel.org,
platform-driver-x86@vger.kernel.org, linux-coco@lists.linux.dev,
linux-mm@kvack.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
Tom Lendacky <thomas.lendacky@amd.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Ard Biesheuvel <ardb@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Jim Mattson <jmattson@google.com>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Sergio Lopez <slp@redhat.com>, Peter Gonda <pgonda@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
David Rientjes <rientjes@google.com>,
Dov Murik <dovmurik@linux.ibm.com>,
Tobin Feldman-Fitzthum <tobin@ibm.com>,
Vlastimil Babka <vbabka@suse.cz>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
Andi Kleen <ak@linux.intel.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
brijesh.ksingh@gmail.com, tony.luck@intel.com,
marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com
Subject: Re: [PATCH v9 05/43] x86/compressed/64: Detect/setup SEV/SME features earlier in boot
Date: Tue, 1 Feb 2022 22:28:39 +0100 [thread overview]
Message-ID: <YfmmBykN2s0HsiAJ@zn.tnic> (raw)
In-Reply-To: <20220201203507.goibbaln6dxyoogv@amd.com>
On Tue, Feb 01, 2022 at 02:35:07PM -0600, Michael Roth wrote:
> Unfortunately rdmsr()/wrmsr()/__rdmsr()/__wrmsr() etc. definitions are all
> already getting pulled in via:
>
> misc.h:
> #include linux/elf.h
> #include linux/thread_info.h
> #include linux/cpufeature.h
> #include linux/processor.h
> #include linux/msr.h
>
> Those definitions aren't usable in boot/compressed because of __ex_table
> and possibly some other dependency hellishness.
And they should not be. Mixing kernel proper and decompressor code needs
to stop and untangling that is a multi-year effort, unfortunately. ;-\
> Would read_msr()/write_msr() be reasonable alternative names for these new
> helpers, or something else that better distinguishes them from the
> kernel proper definitions?
Nah, just call them rdmsr/wrmsr(). There is already {read,write}_msr()
tracepoint symbols in kernel proper and there's no point in keeping them
apart using different names - that ship has long sailed.
> It doesn't look like anything in boot/ pulls in boot/compressed/
> headers. It seems to be the other way around, with boot/compressed
> pulling in headers and whole C files from boot/.
>
> So perhaps these new definitions should be added to a small boot/msr.h
> header and pulled in from there?
That sounds good too.
> Should we introduce something like this as well for cpucheck.c? Or
> re-write cpucheck.c to make use of the u64 versions? Or just set the
> cpucheck.c rework aside for now? (but still introduce the above helpers
> as boot/msr.h in preparation)?
How about you model it after
static int msr_read(u32 msr, struct msr *m)
from arch/x86/lib/msr.c which takes struct msr from which you can return
either u32s or a u64?
The stuff you share between the decompressor and kernel proper you put
in a arch/x86/include/asm/shared/ folder, for an example, see what we do
there in the TDX patchset:
https://lore.kernel.org/r/20220124150215.36893-11-kirill.shutemov@linux.intel.com
I.e., you move struct msr in such a shared header and then you include
it everywhere needed.
The arch/x86/boot/ msr helpers are then plain and simple, without
tracepoints and exception fixups and you define them in ...boot/msr.c or
so.
If the patch gets too big, make sure to split it in a couple so that it
is clear what happens at each step.
How does that sound?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2022-02-01 21:28 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-28 17:17 [PATCH v9 00/43] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 01/43] KVM: SVM: Define sev_features and vmpl field in the VMSA Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 02/43] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2022-02-01 13:02 ` Borislav Petkov
2022-02-09 15:02 ` Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 03/43] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 04/43] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 05/43] x86/compressed/64: Detect/setup SEV/SME features earlier in boot Brijesh Singh
2022-02-01 18:08 ` Borislav Petkov
2022-02-01 20:35 ` Michael Roth
2022-02-01 21:28 ` Borislav Petkov [this message]
2022-02-02 0:52 ` Michael Roth
2022-02-02 6:09 ` Borislav Petkov
2022-02-02 17:28 ` Michael Roth
2022-02-02 18:57 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 06/43] x86/sev: " Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 07/43] x86/mm: Extend cc_attr to include AMD SEV-SNP Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 08/43] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 09/43] x86/sev: Save the negotiated GHCB version Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 10/43] x86/sev: Check SEV-SNP features support Brijesh Singh
2022-02-01 19:59 ` Borislav Petkov
2022-02-02 14:28 ` Brijesh Singh
2022-02-02 15:37 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 11/43] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 12/43] x86/sev: Check the vmpl level Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 13/43] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 14/43] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 15/43] x86/sev: " Brijesh Singh
2022-02-02 10:34 ` Borislav Petkov
2022-02-02 14:29 ` Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 16/43] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 17/43] x86/kernel: Make the .bss..decrypted section shared in RMP table Brijesh Singh
2022-02-02 11:06 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 18/43] x86/kernel: Validate ROM memory before accessing when SEV-SNP is active Brijesh Singh
2022-02-02 15:41 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 19/43] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2022-02-02 16:10 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 20/43] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2022-02-03 6:50 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 21/43] x86/head/64: Re-enable stack protection Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 22/43] x86/sev: Move MSR-based VMGEXITs for CPUID to helper Brijesh Singh
2022-02-03 13:59 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 23/43] KVM: x86: Move lookup of indexed CPUID leafs " Brijesh Singh
2022-02-03 15:16 ` Borislav Petkov
2022-02-03 16:44 ` Michael Roth
2022-02-05 12:58 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 24/43] x86/compressed/acpi: Move EFI detection " Brijesh Singh
2022-02-03 14:39 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 25/43] x86/compressed/acpi: Move EFI system table lookup " Brijesh Singh
2022-02-03 14:48 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 26/43] x86/compressed/acpi: Move EFI config " Brijesh Singh
2022-02-03 15:13 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 27/43] x86/compressed/acpi: Move EFI vendor " Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 28/43] x86/compressed/acpi: Move EFI kexec handling into common code Brijesh Singh
2022-02-04 16:09 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 29/43] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2022-02-04 16:21 ` Borislav Petkov
2022-02-04 17:41 ` Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 30/43] KVM: SEV: Add documentation for SEV-SNP CPUID Enforcement Brijesh Singh
2022-02-07 23:48 ` Sean Christopherson
2022-02-08 14:54 ` Michael Roth
2022-02-08 15:11 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 31/43] x86/compressed/64: Add support for SEV-SNP CPUID table in #VC handlers Brijesh Singh
2022-02-05 10:54 ` Borislav Petkov
2022-02-05 15:42 ` Michael Roth
2022-02-05 16:22 ` Michael Roth
2022-02-06 13:37 ` Borislav Petkov
2022-02-07 15:37 ` Michael Roth
2022-02-07 17:52 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 32/43] x86/boot: Add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2022-02-05 13:07 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 33/43] x86/compressed: Add SEV-SNP feature detection/setup Brijesh Singh
2022-02-06 16:41 ` Borislav Petkov
2022-02-08 13:50 ` Michael Roth
2022-02-08 15:02 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 34/43] x86/compressed: Use firmware-validated CPUID leaves for SEV-SNP guests Brijesh Singh
2022-01-28 17:17 ` [PATCH v9 35/43] x86/compressed: Export and rename add_identity_map() Brijesh Singh
2022-02-06 19:01 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 36/43] x86/compressed/64: Add identity mapping for Confidential Computing blob Brijesh Singh
2022-02-06 19:21 ` Borislav Petkov
2022-01-28 17:17 ` [PATCH v9 37/43] x86/sev: Add SEV-SNP feature detection/setup Brijesh Singh
2022-02-06 19:38 ` Borislav Petkov
2022-02-08 5:25 ` Michael Roth
2022-01-28 17:17 ` [PATCH v9 38/43] x86/sev: Use firmware-validated CPUID for SEV-SNP guests Brijesh Singh
2022-02-05 17:19 ` Michael Roth
2022-02-06 15:46 ` Borislav Petkov
2022-02-07 17:00 ` Michael Roth
2022-02-07 18:43 ` Borislav Petkov
2022-02-06 19:50 ` Borislav Petkov
2022-01-28 17:18 ` [PATCH v9 39/43] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2022-02-01 20:17 ` Peter Gonda
2022-01-28 17:18 ` [PATCH v9 40/43] x86/sev: Register SEV-SNP guest request platform device Brijesh Singh
2022-02-01 20:21 ` Peter Gonda
2022-02-02 16:27 ` Brijesh Singh
2022-02-06 20:05 ` Borislav Petkov
2022-01-28 17:18 ` [PATCH v9 41/43] virt: Add SEV-SNP guest driver Brijesh Singh
2022-02-01 20:33 ` Peter Gonda
2022-02-06 22:39 ` Borislav Petkov
2022-02-07 14:41 ` Brijesh Singh
2022-02-07 15:22 ` Borislav Petkov
2022-01-28 17:18 ` [PATCH v9 42/43] virt: sevguest: Add support to derive key Brijesh Singh
2022-02-01 20:39 ` Peter Gonda
2022-02-02 22:31 ` Brijesh Singh
2022-02-07 8:52 ` Borislav Petkov
2022-02-07 16:23 ` Brijesh Singh
2022-02-07 19:09 ` Dov Murik
2022-02-07 20:08 ` Brijesh Singh
2022-02-07 20:28 ` Borislav Petkov
2022-02-08 7:56 ` Dov Murik
2022-02-08 10:51 ` Borislav Petkov
2022-02-08 14:14 ` Brijesh Singh
2022-01-28 17:18 ` [PATCH v9 43/43] virt: sevguest: Add support to get extended report Brijesh Singh
2022-02-01 20:43 ` Peter Gonda
2022-02-07 9:16 ` Borislav Petkov
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