linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jim Mattson <jmattson@google.com>
To: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Oliver Upton <oupton@google.com>, Peter Shier <pshier@google.com>
Subject: Re: [PATCH v2 02/21] KVM: VMX: Drop bits 31:16 when shoving exception error code into VMCS
Date: Wed, 6 Jul 2022 13:02:52 -0700	[thread overview]
Message-ID: <CALMp9eRm_n4s-ryw5-JiD8-5S+r+F15pSFsQSqava6gHrYjJBg@mail.gmail.com> (raw)
In-Reply-To: <20220614204730.3359543-3-seanjc@google.com>

On Tue, Jun 14, 2022 at 1:47 PM Sean Christopherson <seanjc@google.com> wrote:
>
> Deliberately truncate the exception error code when shoving it into the
> VMCS (VM-Entry field for vmcs01 and vmcs02, VM-Exit field for vmcs12).
> Intel CPUs are incapable of handling 32-bit error codes and will never

Never say "never." :-)

> generate an error code with bits 31:16, but userspace can provide an
> arbitrary error code via KVM_SET_VCPU_EVENTS.  Failure to drop the bits
> on exception injection results in failed VM-Entry, as VMX disallows
> setting bits 31:16.  Setting the bits on VM-Exit would at best confuse
> L1, and at worse induce a nested VM-Entry failure, e.g. if L1 decided to
> reinject the exception back into L2.
>
> Cc: stable@vger.kernel.org
> Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>

  parent reply	other threads:[~2022-07-06 20:03 UTC|newest]

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-14 20:47 [PATCH v2 00/21] KVM: x86: Event/exception fixes and cleanups Sean Christopherson
2022-06-14 20:47 ` [PATCH v2 01/21] KVM: nVMX: Unconditionally purge queued/injected events on nested "exit" Sean Christopherson
2022-06-16 23:47   ` Jim Mattson
2022-07-06 11:40   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 02/21] KVM: VMX: Drop bits 31:16 when shoving exception error code into VMCS Sean Christopherson
2022-07-06 11:43   ` Maxim Levitsky
2022-07-06 16:12     ` Sean Christopherson
2022-07-06 18:50       ` Maxim Levitsky
2022-07-06 20:02   ` Jim Mattson [this message]
2022-06-14 20:47 ` [PATCH v2 03/21] KVM: x86: Don't check for code breakpoints when emulating on exception Sean Christopherson
2022-07-06 11:43   ` Maxim Levitsky
2022-07-06 22:17   ` Jim Mattson
2022-06-14 20:47 ` [PATCH v2 04/21] KVM: nVMX: Treat General Detect #DB (DR7.GD=1) as fault-like Sean Christopherson
2022-07-06 11:45   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 05/21] KVM: nVMX: Prioritize TSS T-flag #DBs over Monitor Trap Flag Sean Christopherson
2022-07-06 11:57   ` Maxim Levitsky
2022-07-06 23:51   ` Jim Mattson
2022-07-07 17:14     ` Sean Christopherson
2022-06-14 20:47 ` [PATCH v2 06/21] KVM: x86: Treat #DBs from the emulator as fault-like (code and DR7.GD=1) Sean Christopherson
2022-07-06 11:57   ` Maxim Levitsky
2022-07-06 23:55   ` Jim Mattson
2022-07-07 17:19     ` Sean Christopherson
2022-06-14 20:47 ` [PATCH v2 07/21] KVM: x86: Use DR7_GD macro instead of open coding check in emulator Sean Christopherson
2022-07-06 11:58   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 08/21] KVM: nVMX: Ignore SIPI that arrives in L2 when vCPU is not in WFS Sean Christopherson
2022-07-06 11:59   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 09/21] KVM: nVMX: Unconditionally clear mtf_pending on nested VM-Exit Sean Christopherson
2022-07-06 12:00   ` Maxim Levitsky
2022-07-06 16:45     ` Sean Christopherson
2022-07-06 20:03       ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 10/21] KVM: VMX: Inject #PF on ENCLS as "emulated" #PF Sean Christopherson
2022-07-06 12:00   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 11/21] KVM: x86: Rename kvm_x86_ops.queue_exception to inject_exception Sean Christopherson
2022-07-06 12:01   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 12/21] KVM: x86: Make kvm_queued_exception a properly named, visible struct Sean Christopherson
2022-07-06 12:02   ` Maxim Levitsky
2022-07-18 13:07   ` Maxim Levitsky
2022-07-18 13:10     ` Maxim Levitsky
2022-07-18 15:40       ` Sean Christopherson
2022-06-14 20:47 ` [PATCH v2 13/21] KVM: x86: Formalize blocking of nested pending exceptions Sean Christopherson
2022-07-06 12:04   ` Maxim Levitsky
2022-07-06 17:36     ` Sean Christopherson
2022-07-06 20:03       ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 14/21] KVM: x86: Use kvm_queue_exception_e() to queue #DF Sean Christopherson
2022-07-06 12:04   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 15/21] KVM: x86: Hoist nested event checks above event injection logic Sean Christopherson
2022-07-06 12:05   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 16/21] KVM: x86: Evaluate ability to inject SMI/NMI/IRQ after potential VM-Exit Sean Christopherson
2022-07-06 12:05   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 17/21] KVM: x86: Morph pending exceptions to pending VM-Exits at queue time Sean Christopherson
2022-07-06 12:15   ` Maxim Levitsky
2022-07-07  1:24     ` Sean Christopherson
2022-07-10 15:56       ` Maxim Levitsky
2022-07-11 15:22         ` Sean Christopherson
2022-06-14 20:47 ` [PATCH v2 18/21] KVM: x86: Treat pending TRIPLE_FAULT requests as pending exceptions Sean Christopherson
2022-07-06 12:16   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 19/21] KVM: VMX: Update MTF and ICEBP comments to document KVM's subtle behavior Sean Christopherson
2022-06-14 20:47 ` [PATCH v2 20/21] KVM: selftests: Use uapi header to get VMX and SVM exit reasons/codes Sean Christopherson
2022-07-06 12:16   ` Maxim Levitsky
2022-06-14 20:47 ` [PATCH v2 21/21] KVM: selftests: Add an x86-only test to verify nested exception queueing Sean Christopherson
2022-07-06 12:17   ` Maxim Levitsky
2022-06-16 13:16 ` [PATCH v2 00/21] KVM: x86: Event/exception fixes and cleanups Maxim Levitsky
2022-06-29 11:16 ` Maxim Levitsky
2022-06-29 13:42   ` Jim Mattson
2022-06-30  8:22     ` Maxim Levitsky
2022-06-30 12:17       ` Jim Mattson
2022-06-30 13:10         ` Maxim Levitsky
2022-06-30 16:28       ` Jim Mattson
2022-07-01  7:37         ` Maxim Levitsky
2022-07-06 11:54     ` Maxim Levitsky
2022-07-06 17:13       ` Jim Mattson
2022-07-06 17:52         ` Sean Christopherson
2022-07-06 20:03           ` Maxim Levitsky
2022-07-06 20:11           ` Jim Mattson
2022-07-10 15:58             ` Maxim Levitsky
2022-06-29 15:53   ` Jim Mattson
2022-06-30  8:24     ` Maxim Levitsky
2022-06-30 12:20       ` Jim Mattson

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=CALMp9eRm_n4s-ryw5-JiD8-5S+r+F15pSFsQSqava6gHrYjJBg@mail.gmail.com \
    --to=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=oupton@google.com \
    --cc=pbonzini@redhat.com \
    --cc=pshier@google.com \
    --cc=seanjc@google.com \
    --cc=vkuznets@redhat.com \
    --cc=wanpengli@tencent.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;
as well as URLs for NNTP newsgroup(s).