From: Paolo Bonzini <pbonzini@redhat.com>
To: Cathy Zhang <cathy.zhang@intel.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
x86@kernel.org
Cc: sean.j.christopherson@intel.com, gregkh@linuxfoundation.org,
tglx@linutronix.de, tony.luck@intel.com, dave.hansen@intel.com,
kyung.min.park@intel.com, ricardo.neri-calderon@linux.intel.com,
vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com,
joro@8bytes.org, mingo@redhat.com, bp@alien8.de, hpa@zytor.com,
jpoimboe@redhat.com, ak@linux.intel.com,
ravi.v.shankar@intel.com
Subject: Re: [PATCH v3 2/2] x86/kvm: Expose new features for supported cpuid
Date: Sun, 9 Aug 2020 19:14:13 +0200 [thread overview]
Message-ID: <d7e9fb9a-e392-73b1-5fc8-3876cb30665c@redhat.com> (raw)
In-Reply-To: <1596959242-2372-3-git-send-email-cathy.zhang@intel.com>
On 09/08/20 09:47, Cathy Zhang wrote:
> Expose the SERIALIZE and TSX Suspend Load Address Tracking
> features in KVM CPUID, so when running on processors which
> support them, KVM could pass this information to guests and
> they can make use of these features accordingly.
>
> SERIALIZE is a faster serializing instruction which does not modify
> registers, arithmetic flags or memory, will not cause VM exit. It's
> availability is indicated by CPUID.(EAX=7,ECX=0):ECX[bit 14].
>
> TSX suspend load tracking instruction aims to give a way to choose
> which memory accesses do not need to be tracked in the TSX read set.
> It's availability is indicated as CPUID.(EAX=7,ECX=0):EDX[bit 16].
>
> Those instructions are currently documented in the the latest "extensions"
> manual (ISE). It will appear in the "main" manual (SDM) in the future.
>
> Signed-off-by: Cathy Zhang <cathy.zhang@intel.com>
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> ---
> Changes since v2:
> * Merge two patches into a single one. (Luck, Tony)
> * Add overview introduction for features. (Sean Christopherson)
> * Refactor commit message to explain why expose feature bits. (Luck, Tony)
> ---
> arch/x86/kvm/cpuid.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
> index 8a294f9..dcf48cc 100644
> --- a/arch/x86/kvm/cpuid.c
> +++ b/arch/x86/kvm/cpuid.c
> @@ -341,7 +341,8 @@ void kvm_set_cpu_caps(void)
> kvm_cpu_cap_mask(CPUID_7_EDX,
> F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
> F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
> - F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM)
> + F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) |
> + F(SERIALIZE) | F(TSXLDTRK)
> );
>
> /* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */
>
TSXLDTRK is not going to be in 5.9 as far as I can see, so I split back
again the patches (this is why I prefer them to be split, sorry Tony :))
and committed the SERIALIZE part.
Paolo
next prev parent reply other threads:[~2020-08-09 17:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-09 7:47 [PATCH v3 0/2] Expose new features for Intel processor Cathy Zhang
2020-08-09 7:47 ` [PATCH v3 1/2] x86/cpufeatures: Enumerate TSX suspend load address tracking instructions Cathy Zhang
2020-08-09 7:47 ` [PATCH v3 2/2] x86/kvm: Expose new features for supported cpuid Cathy Zhang
2020-08-09 17:14 ` Paolo Bonzini [this message]
2020-08-10 23:50 ` Zhang, Cathy
2020-08-10 23:59 ` Luck, Tony
2020-08-11 0:18 ` Zhang, Cathy
2020-08-11 8:32 ` Paolo Bonzini
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=d7e9fb9a-e392-73b1-5fc8-3876cb30665c@redhat.com \
--to=pbonzini@redhat.com \
--cc=ak@linux.intel.com \
--cc=bp@alien8.de \
--cc=cathy.zhang@intel.com \
--cc=dave.hansen@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=jpoimboe@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=kyung.min.park@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=ravi.v.shankar@intel.com \
--cc=ricardo.neri-calderon@linux.intel.com \
--cc=sean.j.christopherson@intel.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.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;
as well as URLs for NNTP newsgroup(s).