From: Dave Hansen <dave.hansen@intel.com>
To: David Woodhouse <dwmw@amazon.co.uk>,
arjan@linux.intel.com, tglx@linutronix.de, karahmed@amazon.de,
x86@kernel.org, linux-kernel@vger.kernel.org,
tim.c.chen@linux.intel.com, bp@alien8.de, peterz@infradead.org,
pbonzini@redhat.com, ak@linux.intel.com,
torvalds@linux-foundation.org, gregkh@linux-foundation.org,
gnomes@lxorguk.ukuu.org.uk, ashok.raj@intel.com,
mingo@kernel.org
Subject: Re: [PATCH v5 5/7] x86/pti: Do not enable PTI on processors which are not vulnerable to Meltdown
Date: Thu, 25 Jan 2018 10:10:52 -0800 [thread overview]
Message-ID: <b6eb62a7-439c-7d21-3e12-db72e5ba1e13@intel.com> (raw)
In-Reply-To: <1516896855-7642-6-git-send-email-dwmw@amazon.co.uk>
On 01/25/2018 08:14 AM, David Woodhouse wrote:
> +static bool __init early_cpu_vulnerable_meltdown(struct cpuinfo_x86 *c)
> +{
> + u64 ia32_cap = 0;
> +
> + if (x86_match_cpu(cpu_no_meltdown))
> + return false;
> +
> + if (cpu_has(c, X86_FEATURE_ARCH_CAPABILITIES))
> + rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
> +
> + /* Rogue Data Cache Load? No! */
> + if (ia32_cap & ARCH_CAP_RDCL_NO)
> + return false;
> +
> + return true;
> +}
Feel free to add my ack on this. It looks fine to me. I'll test and
submit any necessary fixes once I actually get a system that has this bit.
next prev parent reply other threads:[~2018-01-25 18:10 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-25 16:14 [PATCH v5 0/7] Basic Speculation Control feature support David Woodhouse
2018-01-25 16:14 ` [PATCH v5 1/7] x86/cpufeatures: Add CPUID_7_EDX CPUID leaf David Woodhouse
2018-01-26 14:59 ` [tip:x86/pti] " tip-bot for David Woodhouse
2018-01-25 16:14 ` [PATCH v5 2/7] x86/cpufeatures: Add Intel feature bits for Speculation Control David Woodhouse
2018-01-26 15:00 ` [tip:x86/pti] " tip-bot for David Woodhouse
2018-01-25 16:14 ` [PATCH v5 3/7] x86/cpufeatures: Add AMD " David Woodhouse
2018-01-25 21:30 ` Borislav Petkov
2018-01-25 21:37 ` Thomas Gleixner
2018-01-25 21:41 ` Borislav Petkov
2018-01-26 15:00 ` [tip:x86/pti] " tip-bot for David Woodhouse
2018-01-26 18:41 ` [PATCH] x86/cpufeatures: Cleanup AMD speculation feature bits Borislav Petkov
2018-01-26 18:45 ` David Woodhouse
2018-01-26 18:49 ` Borislav Petkov
2018-01-26 21:06 ` Tom Lendacky
2018-01-26 21:52 ` Borislav Petkov
2018-01-26 21:59 ` David Woodhouse
2018-01-26 22:10 ` Borislav Petkov
2018-01-26 23:14 ` Tom Lendacky
2018-01-27 8:49 ` David Woodhouse
2018-01-27 9:27 ` David Woodhouse
2018-01-27 9:37 ` Borislav Petkov
2018-01-27 10:32 ` David Woodhouse
2018-01-27 13:18 ` Borislav Petkov
2018-01-25 16:14 ` [PATCH v5 4/7] x86/msr: Add definitions for new speculation control MSRs David Woodhouse
2018-01-26 15:00 ` [tip:x86/pti] " tip-bot for David Woodhouse
2018-01-25 16:14 ` [PATCH v5 5/7] x86/pti: Do not enable PTI on processors which are not vulnerable to Meltdown David Woodhouse
2018-01-25 18:10 ` Dave Hansen [this message]
2018-01-25 19:53 ` Dave Hansen
2018-01-25 22:00 ` Borislav Petkov
2018-01-26 15:01 ` [tip:x86/pti] x86/pti: Do not enable PTI on CPUs " tip-bot for David Woodhouse
2018-01-25 16:14 ` [PATCH v5 6/7] x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes David Woodhouse
2018-01-26 15:01 ` [tip:x86/pti] " tip-bot for David Woodhouse
2018-01-25 16:14 ` [PATCH v5 7/7] x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support David Woodhouse
2018-01-26 15:02 ` [tip:x86/pti] " tip-bot for David Woodhouse
2018-01-26 16:18 ` David Woodhouse
2018-01-26 21:36 ` [PATCH v5 7/7] " Tim Chen
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=b6eb62a7-439c-7d21-3e12-db72e5ba1e13@intel.com \
--to=dave.hansen@intel.com \
--cc=ak@linux.intel.com \
--cc=arjan@linux.intel.com \
--cc=ashok.raj@intel.com \
--cc=bp@alien8.de \
--cc=dwmw@amazon.co.uk \
--cc=gnomes@lxorguk.ukuu.org.uk \
--cc=gregkh@linux-foundation.org \
--cc=karahmed@amazon.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=tim.c.chen@linux.intel.com \
--cc=torvalds@linux-foundation.org \
--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®