From: Borislav Petkov <bp@alien8.de>
To: Brijesh Singh <brijesh.singh@amd.com>
Cc: 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, linux-crypto@vger.kernel.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>,
Wanpeng Li <wanpengli@tencent.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>,
Michael Roth <michael.roth@amd.com>,
Vlastimil Babka <vbabka@suse.cz>,
tony.luck@intel.com, npmccallum@redhat.com,
brijesh.ksingh@gmail.com
Subject: Re: [PATCH Part1 RFC v4 08/36] x86/sev: check the vmpl level
Date: Fri, 13 Aug 2021 17:16:48 +0200 [thread overview]
Message-ID: <YRaM4LK/mQS+/pOm@zn.tnic> (raw)
In-Reply-To: <bd5b8826-ab0b-4f4f-8594-0c7e6232941a@amd.com>
On Fri, Aug 13, 2021 at 08:13:20AM -0500, Brijesh Singh wrote:
> During the firmware initialization the PSP requires that the VMPLEn is
> set. See SNP firmware spec [1] section 8.6. To run the SNP guest you
> *must* specify a VMPL level during the vCPU creation.
Yes, that's why I said "implicit VMPL level 0"! When you don't specify
it, it should implied as 0.
Right now that "enable" bit is useless as it is *forced* to be enabled.
I sincerely hope querying the VMPL level is going to be made
straight-forwaed in future versions.
> I should not say its optional when we know from the SEV-SNP spec that
> VMPLEn must be set to launch SEV-SNP guest. I will fix the description.
It probably wasn't required when that bit was invented - why would you
call it "enable" otherwise - but some decision later made it required,
I'd guess.
> There is no easy way for a guest to query its VMPL level.
Yes, and there should be.
> The VMPL level is set during the vCPU creation. The boot cpu is
> created by the HV and thus its VMPL level is set by the HV. If HV
> chooses a lower VMPL level for the boot CPU then Linux guest will
> not be able to validate its memory because the PVALIDATE instruction
> will cause #GP when the vCPU is running at !VMPL0. The patch tries to
> detect the boot CPU VMPL level and terminate the boot.
I figured as much. All I don't like is the VMPL checking method.
> If guest is not running at VMPL0 then step #2 will cause #GP. The check
> is prevent the #GP and terminate the boot early.
Yah, Tom helped me understand the design of the permission masks in the
RMP on IRC.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-08-13 15:18 UTC|newest]
Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-07 18:14 [PATCH Part1 RFC v4 00/36] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 01/36] x86/sev: shorten GHCB terminate macro names Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 02/36] x86/sev: Save the negotiated GHCB version Brijesh Singh
2021-08-10 9:17 ` Borislav Petkov
2021-08-10 13:15 ` Brijesh Singh
2021-08-10 10:01 ` Borislav Petkov
2021-08-10 13:17 ` Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 03/36] x86/sev: Add support for hypervisor feature VMGEXIT Brijesh Singh
2021-08-10 11:22 ` Borislav Petkov
2021-08-10 13:39 ` Brijesh Singh
2021-08-10 14:03 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 04/36] x86/mm: Add sev_feature_enabled() helper Brijesh Singh
2021-07-08 8:50 ` Dr. David Alan Gilbert
2021-07-08 8:53 ` Paolo Bonzini
2021-08-10 11:25 ` Borislav Petkov
2021-08-10 14:57 ` Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 05/36] x86/sev: Define the Linux specific guest termination reasons Brijesh Singh
2021-08-10 11:33 ` Borislav Petkov
2021-08-10 14:59 ` Brijesh Singh
2021-08-10 19:30 ` Tom Lendacky
2021-08-10 21:52 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 06/36] x86/sev: check SEV-SNP features support Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 07/36] x86/sev: Add a helper for the PVALIDATE instruction Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 08/36] x86/sev: check the vmpl level Brijesh Singh
2021-08-13 7:25 ` Borislav Petkov
2021-08-13 13:13 ` Brijesh Singh
2021-08-13 15:16 ` Borislav Petkov [this message]
2021-07-07 18:14 ` [PATCH Part1 RFC v4 09/36] x86/compressed: Add helper for validating pages in the decompression stage Brijesh Singh
2021-08-13 10:22 ` Borislav Petkov
2021-08-13 14:21 ` Brijesh Singh
2021-08-13 15:19 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 10/36] x86/compressed: Register GHCB memory when SEV-SNP is active Brijesh Singh
2021-08-13 10:47 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 11/36] x86/sev: " Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 12/36] x86/sev: Add helper for validating pages in early enc attribute changes Brijesh Singh
2021-08-13 11:13 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 13/36] x86/kernel: Make the bss.decrypted section shared in RMP table Brijesh Singh
2021-08-13 17:09 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 14/36] x86/kernel: Validate rom memory before accessing when SEV-SNP is active Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 15/36] x86/mm: Add support to validate memory when changing C-bit Brijesh Singh
2021-08-17 17:27 ` Borislav Petkov
2021-08-17 18:07 ` Brijesh Singh
2021-08-17 18:17 ` Borislav Petkov
2021-08-17 18:18 ` Brijesh Singh
2021-08-17 20:34 ` Brijesh Singh
2021-08-17 20:44 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 16/36] KVM: SVM: define new SEV_FEATURES field in the VMCB Save State Area Brijesh Singh
2021-08-17 17:54 ` Borislav Petkov
2021-08-17 17:59 ` Borislav Petkov
2021-08-17 18:11 ` Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 17/36] KVM: SVM: Create a separate mapping for the SEV-ES save area Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 18/36] KVM: SVM: Create a separate mapping for the GHCB " Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 19/36] KVM: SVM: Update the SEV-ES save area mapping Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 20/36] x86/sev: Use SEV-SNP AP creation to start secondary CPUs Brijesh Singh
2021-08-17 20:04 ` Borislav Petkov
2021-08-17 22:13 ` Tom Lendacky
2021-08-18 8:38 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 21/36] x86/head/64: set up a startup %gs for stack protector Brijesh Singh
2021-08-19 9:34 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 22/36] x86/sev: move MSR-based VMGEXITs for CPUID to helper Brijesh Singh
2021-08-19 9:45 ` Borislav Petkov
2021-08-19 15:37 ` Michael Roth
2021-08-19 16:46 ` Borislav Petkov
2021-08-20 3:29 ` Michael Roth
2021-08-23 4:50 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 23/36] KVM: x86: move lookup of indexed CPUID leafs " Brijesh Singh
2021-08-19 10:07 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 24/36] x86/compressed/acpi: move EFI config table access to common code Brijesh Singh
2021-08-19 10:47 ` Borislav Petkov
2021-08-19 14:58 ` Michael Roth
2021-08-19 17:09 ` Borislav Petkov
2021-08-19 23:42 ` Michael Roth
2021-08-23 4:52 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 25/36] x86/boot: Add Confidential Computing type to setup_data Brijesh Singh
2021-08-19 11:06 ` Borislav Petkov
2021-07-07 18:14 ` [PATCH Part1 RFC v4 26/36] x86/compressed/64: enable SEV-SNP-validated CPUID in #VC handler Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 27/36] x86/boot: add a pointer to Confidential Computing blob in bootparams Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 28/36] x86/compressed/64: store Confidential Computing blob address " Brijesh Singh
2021-07-07 18:14 ` [PATCH Part1 RFC v4 29/36] x86/compressed/64: add identity mapping for Confidential Computing blob Brijesh Singh
2021-07-07 18:15 ` [PATCH Part1 RFC v4 30/36] x86/sev: enable SEV-SNP-validated CPUID in #VC handlers Brijesh Singh
2021-07-07 18:15 ` [PATCH Part1 RFC v4 31/36] x86/sev: Provide support for SNP guest request NAEs Brijesh Singh
2021-07-07 18:15 ` [PATCH Part1 RFC v4 32/36] x86/sev: Add snp_msg_seqno() helper Brijesh Singh
2021-07-07 18:15 ` [PATCH Part1 RFC v4 33/36] x86/sev: Register SNP guest request platform device Brijesh Singh
2021-07-07 18:15 ` [PATCH Part1 RFC v4 34/36] virt: Add SEV-SNP guest driver Brijesh Singh
2021-07-07 18:15 ` [PATCH Part1 RFC v4 35/36] virt: sevguest: Add support to derive key Brijesh Singh
2021-07-07 18:15 ` [PATCH Part1 RFC v4 36/36] virt: sevguest: Add support to get extended report Brijesh Singh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YRaM4LK/mQS+/pOm@zn.tnic \
--to=bp@alien8.de \
--cc=ardb@kernel.org \
--cc=brijesh.ksingh@gmail.com \
--cc=brijesh.singh@amd.com \
--cc=dave.hansen@linux.intel.com \
--cc=dovmurik@linux.ibm.com \
--cc=hpa@zytor.com \
--cc=jmattson@google.com \
--cc=jroedel@suse.de \
--cc=kvm@vger.kernel.org \
--cc=linux-coco@lists.linux.dev \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=michael.roth@amd.com \
--cc=mingo@redhat.com \
--cc=npmccallum@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=pgonda@google.com \
--cc=platform-driver-x86@vger.kernel.org \
--cc=rientjes@google.com \
--cc=seanjc@google.com \
--cc=slp@redhat.com \
--cc=srinivas.pandruvada@linux.intel.com \
--cc=tglx@linutronix.de \
--cc=thomas.lendacky@amd.com \
--cc=tobin@ibm.com \
--cc=tony.luck@intel.com \
--cc=vbabka@suse.cz \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).