From: Sean Christopherson <seanjc@google.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Andy Lutomirski <luto@kernel.org>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Andi Kleen <ak@linux.intel.com>,
Kirill Shutemov <kirill.shutemov@linux.intel.com>,
Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
Raj Ashok <ashok.raj@intel.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC v1 09/26] x86/tdx: Handle CPUID via #VE
Date: Mon, 8 Feb 2021 09:47:27 -0800 [thread overview]
Message-ID: <YCF5LyZCIXkLV9ln@google.com> (raw)
In-Reply-To: <CALCETrWC8qEFuUBdknaU-u_BbB1+HEibAKSjygH_bX0fYR1hYg@mail.gmail.com>
On Mon, Feb 08, 2021, Andy Lutomirski wrote:
> On Mon, Feb 8, 2021 at 9:11 AM Sean Christopherson <seanjc@google.com> wrote:
> >
> > On Sun, Feb 07, 2021, Andy Lutomirski wrote:
> > >
>
> > > How much of the register state is revealed to the VMM when we do a TDVMCALL?
> > > Presumably we should fully sanitize all register state that shows up in
> > > cleartext on the other end, and we should treat all regs that can be modified
> > > by the VMM as clobbered.
> >
> > The guest gets to choose, with a few restrictions. RSP cannot be exposed to the
> > host. RAX, RCX, R10, and R11 are always exposed as they hold mandatory info
> > about the TDVMCALL (TDCALL fn, GPR mask, GHCI vs. vendor, and TDVMCALL fn). All
> > other GPRs are exposed and clobbered if their bit in RCX is set, otherwise they
> > are saved/restored by the TDX-Module.
> >
> > I agree with Dave, pass everything required by the GHCI in the main routine, and
> > sanitize and save/restore all such GPRs.
>
> Sounds okay to me.
One clarification: only non-volatile GPRs (R12-R15) need to be saved/restored.
And I think it makes sense to sanitize any exposed GPRs (that don't hold an
output value) after TDVMCALL to avoid speculating with a host-controlled value.
next prev parent reply other threads:[~2021-02-08 19:09 UTC|newest]
Thread overview: 161+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-06 3:02 Test Email sathyanarayanan.kuppuswamy
2021-02-05 23:38 ` [RFC v1 00/26] Add TDX Guest Support Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 01/26] x86/paravirt: Introduce CONFIG_PARAVIRT_XL Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 02/26] x86/cpufeatures: Add TDX Guest CPU feature Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 03/26] x86/cpufeatures: Add is_tdx_guest() interface Kuppuswamy Sathyanarayanan
2021-04-01 21:08 ` Dave Hansen
2021-04-01 21:15 ` Kuppuswamy, Sathyanarayanan
2021-04-01 21:19 ` Dave Hansen
2021-04-01 22:25 ` Kuppuswamy, Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 04/26] x86/tdx: Get TD execution environment information via TDINFO Kuppuswamy Sathyanarayanan
2021-02-08 10:00 ` Peter Zijlstra
2021-02-08 19:10 ` Kuppuswamy, Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 05/26] x86/traps: Add #VE support for TDX guest Kuppuswamy Sathyanarayanan
2021-02-08 10:20 ` Peter Zijlstra
2021-02-08 16:23 ` Andi Kleen
2021-02-08 16:33 ` Peter Zijlstra
2021-02-08 16:46 ` Sean Christopherson
2021-02-08 16:59 ` Peter Zijlstra
2021-02-08 19:05 ` Kuppuswamy, Sathyanarayanan
2021-02-08 16:46 ` Andi Kleen
2021-02-12 19:20 ` Dave Hansen
2021-02-12 19:47 ` Andy Lutomirski
2021-02-12 20:06 ` Sean Christopherson
2021-02-12 20:17 ` Dave Hansen
2021-02-12 20:37 ` Sean Christopherson
2021-02-12 20:46 ` Dave Hansen
2021-02-12 20:54 ` Sean Christopherson
2021-02-12 21:06 ` Dave Hansen
2021-02-12 21:37 ` Sean Christopherson
2021-02-12 21:47 ` Andy Lutomirski
2021-02-12 21:48 ` Dave Hansen
2021-02-14 19:33 ` Andi Kleen
2021-02-14 19:54 ` Andy Lutomirski
2021-02-12 20:20 ` Andy Lutomirski
2021-02-12 20:44 ` Sean Christopherson
2021-02-05 23:38 ` [RFC v1 06/26] x86/tdx: Add HLT " Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 07/26] x86/tdx: Wire up KVM hypercalls Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 08/26] x86/tdx: Add MSR support for TDX guest Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 09/26] x86/tdx: Handle CPUID via #VE Kuppuswamy Sathyanarayanan
2021-02-05 23:42 ` Andy Lutomirski
2021-02-07 14:13 ` Kirill A. Shutemov
2021-02-07 16:01 ` Dave Hansen
2021-02-07 20:29 ` Kirill A. Shutemov
2021-02-07 22:31 ` Dave Hansen
2021-02-07 22:45 ` Andy Lutomirski
2021-02-08 17:10 ` Sean Christopherson
2021-02-08 17:35 ` Andy Lutomirski
2021-02-08 17:47 ` Sean Christopherson [this message]
2021-03-18 21:30 ` [PATCH v1 1/1] x86/tdx: Add tdcall() and tdvmcall() helper functions Kuppuswamy Sathyanarayanan
2021-03-19 16:55 ` Sean Christopherson
2021-03-19 17:42 ` Kuppuswamy, Sathyanarayanan
2021-03-19 18:22 ` Dave Hansen
2021-03-19 19:58 ` Kuppuswamy, Sathyanarayanan
2021-03-26 23:38 ` [PATCH v2 1/1] x86/tdx: Add __tdcall() and __tdvmcall() " Kuppuswamy Sathyanarayanan
2021-04-20 17:36 ` Dave Hansen
2021-04-20 19:20 ` Kuppuswamy, Sathyanarayanan
2021-04-20 19:59 ` Dave Hansen
2021-04-20 23:12 ` Kuppuswamy, Sathyanarayanan
2021-04-20 23:42 ` Dave Hansen
2021-04-23 1:09 ` Kuppuswamy, Sathyanarayanan
2021-04-23 1:21 ` Dave Hansen
2021-04-23 1:35 ` Andi Kleen
2021-04-23 15:15 ` Sean Christopherson
2021-04-23 15:28 ` Dan Williams
2021-04-23 15:38 ` Andi Kleen
2021-04-23 15:50 ` Sean Christopherson
2021-04-23 15:47 ` Andi Kleen
2021-04-23 18:18 ` Kuppuswamy, Sathyanarayanan
2021-04-20 23:53 ` Dan Williams
2021-04-20 23:59 ` Kuppuswamy, Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 10/26] x86/io: Allow to override inX() and outX() implementation Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 11/26] x86/tdx: Handle port I/O Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 12/26] x86/tdx: Handle in-kernel MMIO Kuppuswamy Sathyanarayanan
2021-04-01 19:56 ` Dave Hansen
2021-04-01 22:26 ` Sean Christopherson
2021-04-01 22:53 ` Dave Hansen
2021-02-05 23:38 ` [RFC v1 13/26] x86/tdx: Handle MWAIT, MONITOR and WBINVD Kuppuswamy Sathyanarayanan
2021-02-05 23:43 ` Andy Lutomirski
2021-02-05 23:54 ` Kuppuswamy, Sathyanarayanan
2021-02-06 1:05 ` Andy Lutomirski
2021-03-27 0:18 ` [PATCH v1 1/1] " Kuppuswamy Sathyanarayanan
2021-03-27 2:40 ` Andy Lutomirski
2021-03-27 3:40 ` Kuppuswamy, Sathyanarayanan
2021-03-27 16:03 ` Andy Lutomirski
2021-03-27 22:54 ` [PATCH v2 " Kuppuswamy Sathyanarayanan
2021-03-29 17:14 ` Dave Hansen
2021-03-29 21:55 ` Kuppuswamy, Sathyanarayanan
2021-03-29 22:02 ` Dave Hansen
2021-03-29 22:09 ` Kuppuswamy, Sathyanarayanan
2021-03-29 22:12 ` Dave Hansen
2021-03-29 22:42 ` Kuppuswamy, Sathyanarayanan
2021-03-29 23:16 ` [PATCH v3 " Kuppuswamy Sathyanarayanan
2021-03-29 23:23 ` Andy Lutomirski
2021-03-29 23:37 ` Kuppuswamy, Sathyanarayanan
2021-03-29 23:42 ` Sean Christopherson
2021-03-29 23:58 ` Andy Lutomirski
2021-03-30 2:04 ` Andi Kleen
2021-03-30 2:58 ` Andy Lutomirski
2021-03-30 15:14 ` Sean Christopherson
2021-03-30 16:37 ` Andy Lutomirski
2021-03-30 16:57 ` Sean Christopherson
2021-04-07 15:24 ` Andi Kleen
2021-03-31 21:09 ` [PATCH v4 " Kuppuswamy Sathyanarayanan
2021-03-31 21:49 ` Dave Hansen
2021-03-31 22:29 ` Kuppuswamy, Sathyanarayanan
2021-03-31 21:53 ` Sean Christopherson
2021-03-31 22:00 ` Dave Hansen
2021-03-31 22:06 ` Sean Christopherson
2021-03-31 22:11 ` Dave Hansen
2021-03-31 22:28 ` Kuppuswamy, Sathyanarayanan
2021-03-31 22:32 ` Sean Christopherson
2021-03-31 22:34 ` Dave Hansen
2021-04-01 3:28 ` Andi Kleen
2021-04-01 3:46 ` Dave Hansen
2021-04-01 4:24 ` Andi Kleen
2021-04-01 4:51 ` [PATCH v5 " Kuppuswamy Sathyanarayanan
2021-03-29 23:39 ` [PATCH v3 " Sean Christopherson
2021-03-29 23:38 ` Dave Hansen
2021-03-30 4:56 ` [PATCH v1 " Xiaoyao Li
2021-03-30 15:00 ` Andi Kleen
2021-03-30 15:10 ` Dave Hansen
2021-03-30 17:02 ` Kuppuswamy, Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 14/26] ACPI: tables: Add multiprocessor wake-up support Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 15/26] x86/boot: Add a trampoline for APs booting in 64-bit mode Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 16/26] x86/boot: Avoid #VE during compressed boot for TDX platforms Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 17/26] x86/boot: Avoid unnecessary #VE during boot process Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 18/26] x86/topology: Disable CPU hotplug support for TDX platforms Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 19/26] x86/tdx: Forcefully disable legacy PIC for TDX guests Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 20/26] x86/tdx: Introduce INTEL_TDX_GUEST config option Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 21/26] x86/mm: Move force_dma_unencrypted() to common code Kuppuswamy Sathyanarayanan
2021-04-01 20:06 ` Dave Hansen
2021-04-06 15:37 ` Kirill A. Shutemov
2021-04-06 16:11 ` Dave Hansen
2021-04-06 16:37 ` Kirill A. Shutemov
2021-02-05 23:38 ` [RFC v1 22/26] x86/tdx: Exclude Shared bit from __PHYSICAL_MASK Kuppuswamy Sathyanarayanan
2021-04-01 20:13 ` Dave Hansen
2021-04-06 15:54 ` Kirill A. Shutemov
2021-04-06 16:12 ` Dave Hansen
2021-02-05 23:38 ` [RFC v1 23/26] x86/tdx: Make pages shared in ioremap() Kuppuswamy Sathyanarayanan
2021-04-01 20:26 ` Dave Hansen
2021-04-06 16:00 ` Kirill A. Shutemov
2021-04-06 16:14 ` Dave Hansen
2021-02-05 23:38 ` [RFC v1 24/26] x86/tdx: Add helper to do MapGPA TDVMALL Kuppuswamy Sathyanarayanan
2021-02-05 23:38 ` [RFC v1 25/26] x86/tdx: Make DMA pages shared Kuppuswamy Sathyanarayanan
2021-04-01 21:01 ` Dave Hansen
2021-04-06 16:31 ` Kirill A. Shutemov
2021-04-06 16:38 ` Dave Hansen
2021-04-06 17:16 ` Sean Christopherson
2021-02-05 23:38 ` [RFC v1 26/26] x86/kvm: Use bounce buffers for TD guest Kuppuswamy Sathyanarayanan
2021-04-01 21:17 ` Dave Hansen
2021-02-06 3:04 ` Test Email sathyanarayanan.kuppuswamy
2021-02-06 6:24 ` [RFC v1 00/26] Add TDX Guest Support sathyanarayanan.kuppuswamy
2021-03-31 21:38 ` Kuppuswamy, Sathyanarayanan
2021-04-02 0:02 ` Dave Hansen
2021-04-02 2:48 ` Andi Kleen
2021-04-02 15:27 ` Dave Hansen
2021-04-02 21:32 ` Andi Kleen
2021-04-03 16:26 ` Dave Hansen
2021-04-03 17:28 ` Andi Kleen
2021-04-04 15:02 ` Dave Hansen
2021-04-12 17:24 ` Dan Williams
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=YCF5LyZCIXkLV9ln@google.com \
--to=seanjc@google.com \
--cc=ak@linux.intel.com \
--cc=ashok.raj@intel.com \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@intel.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=kirill@shutemov.name \
--cc=knsathya@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=peterz@infradead.org \
--cc=sathyanarayanan.kuppuswamy@linux.intel.com \
/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
Powered by JetHome