From: Paolo Bonzini <pbonzini@redhat.com>
To: "Nakajima, Jun" <jun.nakajima@intel.com>,
Thomas Gleixner <tglx@linutronix.de>
Cc: "Liu, Jing2" <jing2.liu@intel.com>,
LKML <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Arjan van de Ven <arjan@linux.intel.com>,
Jing Liu <jing2.liu@linux.intel.com>,
"seanjc@google.com" <seanjc@google.com>,
"Cooper, Andrew" <andrew.cooper3@citrix.com>,
"Bae, Chang Seok" <chang.seok.bae@intel.com>
Subject: Re: Thoughts of AMX KVM support based on latest kernel
Date: Wed, 17 Nov 2021 08:31:17 +0100 [thread overview]
Message-ID: <2e2ab02c-b324-e136-924a-0376040163a8@redhat.com> (raw)
In-Reply-To: <16BF8BE6-B7B1-4F3E-B972-9D82CD2F23C8@intel.com>
On 11/17/21 05:52, Nakajima, Jun wrote:
> If a (creative) guest wants to set XFD[AMX] = 1 for fun while keeping
> AMX state alive without saving the AXM state, it may lose the state
> after VM exit/entry.
I think this should not happen, unless you also document that other
random events (hypothetically, it could be some other core using AMX?)
can cause the loss of XTILEDATA if XFD[AMX]=1. Virtualization should
not be special, I'd prefer that the guest has the same behavior as bare
metal in this respect.
Paolo
next prev parent reply other threads:[~2021-11-17 7:31 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-10 13:01 Thoughts of AMX KVM support based on latest kernel Liu, Jing2
2021-11-16 12:18 ` Thomas Gleixner
2021-11-16 16:05 ` Sean Christopherson
2021-11-16 18:55 ` Thomas Gleixner
2021-11-16 19:49 ` Paolo Bonzini
2021-11-16 20:14 ` Sean Christopherson
2021-11-16 20:36 ` Thomas Gleixner
2021-11-16 22:11 ` Nakajima, Jun
2021-11-17 7:39 ` Paolo Bonzini
2021-11-16 20:12 ` Sean Christopherson
2021-11-16 23:35 ` Thomas Gleixner
2021-11-16 19:20 ` Thomas Gleixner
2021-11-17 4:52 ` Nakajima, Jun
2021-11-17 7:31 ` Paolo Bonzini [this message]
2021-11-17 10:15 ` Tian, Kevin
2021-11-17 12:24 ` Thomas Gleixner
2021-11-17 12:53 ` Paolo Bonzini
2021-11-18 23:17 ` Nakajima, Jun
2021-11-19 10:13 ` Thomas Gleixner
2021-11-19 15:41 ` Nakajima, Jun
2021-12-08 0:50 ` Rewording of Setting IA32_XFD[18] (Re: Thoughts of AMX KVM support based on latest kernel) Nakajima, Jun
2021-12-08 13:57 ` Paolo Bonzini
2021-12-10 21:53 ` Thomas Gleixner
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