From: "Woodhouse, David" <dwmw@amazon.co.uk>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>
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Subject: Re: [RFC][PATCH] x86: proposed new ARCH_CAPABILITIES MSR bit for RSB-underflow
Date: Mon, 19 Feb 2018 14:21:10 +0000 [thread overview]
Message-ID: <1519050070.7876.69.camel@amazon.co.uk> (raw)
In-Reply-To: <20180216191755.6F62DDEA@viggo.jf.intel.com>
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On Fri, 2018-02-16 at 11:17 -0800, Dave Hansen wrote:
> +static bool cpu_has_rsb_override(void)
> +{
> + u64 ia32_cap = 0;
> +
> + if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES))
> + rdmsrl(MSR_IA32_ARCH_CAPABILITIES, ia32_cap);
> +
> + /* RSBO == RSB Override */
> + if (ia32_cap & ARCH_CAP_RSBO)
> + return true;
That would be the third such construct. As some point we should
probably put the bits of MSR_IA32_ARCH_CAPABILITIES into cpufeatures a
bit like the 'scattered' CPUID bits.
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prev parent reply other threads:[~2018-02-19 14:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-16 19:17 [RFC][PATCH] x86: proposed new ARCH_CAPABILITIES MSR bit for RSB-underflow Dave Hansen
2018-02-16 19:38 ` Linus Torvalds
2018-02-16 19:43 ` Linus Torvalds
2018-02-16 19:47 ` Arjan van de Ven
2018-02-19 14:21 ` Woodhouse, David [this message]
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