From: Dave Hansen <dave.hansen@intel.com>
To: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>,
Nikolay Borisov <nik.borisov@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Andy Lutomirski <luto@kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
tony.luck@intel.com, ak@linux.intel.com,
tim.c.chen@linux.intel.com, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, kvm@vger.kernel.org,
Alyssa Milburn <alyssa.milburn@linux.intel.com>,
Daniel Sneddon <daniel.sneddon@linux.intel.com>,
antonio.gomez.iglesias@linux.intel.com
Subject: Re: [PATCH v3 2/6] x86/entry_64: Add VERW just before userspace transition
Date: Thu, 26 Oct 2023 12:40:49 -0700 [thread overview]
Message-ID: <ae3d993f-6ce4-42de-b9c4-ef0c7db663c0@intel.com> (raw)
In-Reply-To: <20231026192950.ylzc66f3f5naqvjv@desk>
On 10/26/23 12:29, Pawan Gupta wrote:
> On Thu, Oct 26, 2023 at 07:25:27PM +0300, Nikolay Borisov wrote:
>> On 25.10.23 г. 23:52 ч., Pawan Gupta wrote:
>>> @@ -1520,6 +1530,7 @@ SYM_CODE_START(ignore_sysret)
>>> UNWIND_HINT_END_OF_STACK
>>> ENDBR
>>> mov $-ENOSYS, %eax
>>> + CLEAR_CPU_BUFFERS
>> nit: Just out of curiosity is it really needed in this case or it's doesn
>> for the sake of uniformity so that all ring3 transitions are indeed
>> covered??
> Interrupts returning to kernel don't clear the CPU buffers. I believe
> interrupts will be enabled here, and getting an interrupt here could
> leak the data that interrupt touched.
Specifically NMIs, right?
X86_EFLAGS_IF should be clear here.
next prev parent reply other threads:[~2023-10-26 19:40 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-25 20:52 [PATCH v3 0/6] Delay VERW Pawan Gupta
2023-10-25 20:52 ` [PATCH v3 1/6] x86/bugs: Add asm helpers for executing VERW Pawan Gupta
2023-10-25 21:10 ` Andrew Cooper
2023-10-25 21:28 ` Josh Poimboeuf
2023-10-25 21:30 ` Andrew Cooper
2023-10-25 21:49 ` Josh Poimboeuf
2023-10-25 22:07 ` Pawan Gupta
2023-10-25 22:13 ` Andrew Cooper
2023-10-27 13:48 ` Pawan Gupta
2023-10-27 14:12 ` Andrew Cooper
2023-10-27 14:24 ` Pawan Gupta
2023-10-26 13:44 ` Nikolay Borisov
2023-10-26 13:58 ` Andrew Cooper
2023-10-25 20:52 ` [PATCH v3 2/6] x86/entry_64: Add VERW just before userspace transition Pawan Gupta
2023-10-26 16:25 ` Nikolay Borisov
2023-10-26 19:29 ` Pawan Gupta
2023-10-26 19:40 ` Dave Hansen [this message]
2023-10-26 21:15 ` Pawan Gupta
2023-10-26 22:13 ` Pawan Gupta
2023-10-26 22:17 ` Dave Hansen
2023-10-25 20:53 ` [PATCH v3 3/6] x86/entry_32: " Pawan Gupta
2023-10-25 20:53 ` [PATCH v3 4/6] x86/bugs: Use ALTERNATIVE() instead of mds_user_clear static key Pawan Gupta
2023-10-25 20:53 ` [PATCH v3 5/6] KVM: VMX: Use BT+JNC, i.e. EFLAGS.CF to select VMRESUME vs. VMLAUNCH Pawan Gupta
2023-10-25 20:53 ` [PATCH v3 6/6] KVM: VMX: Move VERW closer to VMentry for MDS mitigation Pawan Gupta
2023-10-26 16:14 ` Nikolay Borisov
2023-10-26 19:07 ` Pawan Gupta
2023-10-26 19:30 ` Sean Christopherson
2023-10-26 20:17 ` Sean Christopherson
2023-10-26 21:27 ` Pawan Gupta
2023-10-26 20:48 ` Pawan Gupta
2023-10-26 21:22 ` Sean Christopherson
2023-10-26 22:03 ` Pawan Gupta
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=ae3d993f-6ce4-42de-b9c4-ef0c7db663c0@intel.com \
--to=dave.hansen@intel.com \
--cc=ak@linux.intel.com \
--cc=alyssa.milburn@linux.intel.com \
--cc=antonio.gomez.iglesias@linux.intel.com \
--cc=bp@alien8.de \
--cc=corbet@lwn.net \
--cc=daniel.sneddon@linux.intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jpoimboe@kernel.org \
--cc=kvm@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=nik.borisov@suse.com \
--cc=pawan.kumar.gupta@linux.intel.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=seanjc@google.com \
--cc=tglx@linutronix.de \
--cc=tim.c.chen@linux.intel.com \
--cc=tony.luck@intel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.