mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: "Gupta, Pankaj" <pankaj.gupta@amd.com>,
	Tianyu Lan <ltykernel@gmail.com>,
	luto@kernel.org, tglx@linutronix.de, mingo@redhat.com,
	bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org,
	hpa@zytor.com, seanjc@google.com, pbonzini@redhat.com,
	jgross@suse.com, tiala@microsoft.com, kirill@shutemov.name,
	jiangshan.ljs@antgroup.com, ashish.kalra@amd.com,
	srutherford@google.com, akpm@linux-foundation.org,
	anshuman.khandual@arm.com, pawan.kumar.gupta@linux.intel.com,
	adrian.hunter@intel.com, daniel.sneddon@linux.intel.com,
	alexander.shishkin@linux.intel.com, sandipan.das@amd.com,
	ray.huang@amd.com, brijesh.singh@amd.com, michael.roth@amd.com,
	venu.busireddy@oracle.com, sterritt@google.com,
	tony.luck@intel.com, samitolvanen@google.com,
	fenghua.yu@intel.com, pangupta@amd.com,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	linux-hyperv@vger.kernel.org, linux-arch@vger.kernel.org
Subject: Re: [RFC PATCH V6 01/14] x86/sev: Add a #HV exception handler
Date: Wed, 31 May 2023 11:14:52 +0200	[thread overview]
Message-ID: <20230531091452.GG38236@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20230530185232.GA211927@hirez.programming.kicks-ass.net>

On Tue, May 30, 2023 at 08:52:32PM +0200, Peter Zijlstra wrote:

> > That should really say that a nested #HV should never be raised by the
> > hypervisor, but if it is, then the guest should detect that and
> > self-terminate knowing that the hypervisor is possibly being malicious.
> 
> I've yet to see code that can do that reliably.

Tom; could you please investigate if this can be enforced in ucode?

Ideally #HV would have an internal latch such that a recursive #HV will
terminate the guest (much like double #MC and tripple-fault).

But unlike the #MC trainwreck, can we please not leave a glaring hole in
this latch and use a spare bit in the IRET frame please?

So have #HV delivery:
 - check internal latch; if set, terminate machine
 - set latch
 - write IRET frame with magic bit set

have IRET:
 - check magic bit and reset #HV latch


  parent reply	other threads:[~2023-05-31  9:15 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-15 16:59 [RFC PATCH V6 00/14] x86/hyperv/sev: Add AMD sev-snp enlightened guest support on hyperv Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 01/14] x86/sev: Add a #HV exception handler Tianyu Lan
2023-05-16  9:30   ` Peter Zijlstra
2023-05-17  9:01     ` Tianyu Lan
2023-05-30 12:16     ` Gupta, Pankaj
2023-05-30 14:35       ` Peter Zijlstra
2023-05-30 15:59         ` Tom Lendacky
2023-05-30 18:52           ` Peter Zijlstra
2023-05-30 19:03             ` Dave Hansen
2023-05-31  9:14             ` Peter Zijlstra [this message]
2023-06-07 18:19               ` Tom Lendacky
2023-06-06  6:00             ` Gupta, Pankaj
2023-06-06  7:50               ` Peter Zijlstra
2023-05-30 15:18       ` Dave Hansen
2023-05-15 16:59 ` [RFC PATCH V6 02/14] x86/sev: Add Check of #HV event in path Tianyu Lan
2023-05-16  9:32   ` Peter Zijlstra
2023-05-17  9:55     ` Tianyu Lan
2023-05-17 13:09       ` Peter Zijlstra
2023-05-31 14:50         ` Michael Kelley (LINUX)
2023-05-31 15:48           ` Peter Zijlstra
2023-05-31 15:58             ` Michael Kelley (LINUX)
2023-05-15 16:59 ` [RFC PATCH V6 03/14] x86/sev: Add AMD sev-snp enlightened guest support on hyperv Tianyu Lan
2023-05-16  9:40   ` Peter Zijlstra
2023-05-16 15:38     ` Dionna Amalie Glaze
2023-05-15 16:59 ` [RFC PATCH V6 04/14] x86/sev: optimize system vector processing invoked from #HV exception Tianyu Lan
2023-05-16 10:23   ` Peter Zijlstra
2023-05-17 13:28     ` Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 05/14] x86/hyperv: Add sev-snp enlightened guest static key Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 06/14] x86/hyperv: Mark Hyper-V vp assist page unencrypted in SEV-SNP enlightened guest Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 07/14] x86/hyperv: Set Virtual Trust Level in VMBus init message Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 08/14] x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp enlightened guest Tianyu Lan
2023-05-16 10:29   ` Peter Zijlstra
2023-05-15 16:59 ` [RFC PATCH V6 09/14] clocksource/drivers/hyper-v: decrypt hyperv tsc page " Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 10/14] hv: vmbus: Mask VMBus pages unencrypted for " Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 11/14] drivers: hv: Decrypt percpu hvcall input arg page in " Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 12/14] x86/hyperv: Initialize cpu and memory for " Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 13/14] x86/hyperv: Add smp support for sev-snp guest Tianyu Lan
2023-05-16  5:16   ` [EXTERNAL] " Saurabh Singh Sengar
2023-05-17  8:19     ` Tianyu Lan
2023-05-15 16:59 ` [RFC PATCH V6 14/14] x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES Tianyu Lan

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=20230531091452.GG38236@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=adrian.hunter@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=alexander.shishkin@linux.intel.com \
    --cc=anshuman.khandual@arm.com \
    --cc=ashish.kalra@amd.com \
    --cc=bp@alien8.de \
    --cc=brijesh.singh@amd.com \
    --cc=daniel.sneddon@linux.intel.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=fenghua.yu@intel.com \
    --cc=hpa@zytor.com \
    --cc=jgross@suse.com \
    --cc=jiangshan.ljs@antgroup.com \
    --cc=kirill@shutemov.name \
    --cc=kvm@vger.kernel.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ltykernel@gmail.com \
    --cc=luto@kernel.org \
    --cc=michael.roth@amd.com \
    --cc=mingo@redhat.com \
    --cc=pangupta@amd.com \
    --cc=pankaj.gupta@amd.com \
    --cc=pawan.kumar.gupta@linux.intel.com \
    --cc=pbonzini@redhat.com \
    --cc=ray.huang@amd.com \
    --cc=samitolvanen@google.com \
    --cc=sandipan.das@amd.com \
    --cc=seanjc@google.com \
    --cc=srutherford@google.com \
    --cc=sterritt@google.com \
    --cc=tglx@linutronix.de \
    --cc=thomas.lendacky@amd.com \
    --cc=tiala@microsoft.com \
    --cc=tony.luck@intel.com \
    --cc=venu.busireddy@oracle.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
all inboxes | Powered by JetHome®