virtualization.lists.linux-foundation.org archive mirror
 help / color / mirror / Atom feed
From: Paolo Bonzini <pbonzini@redhat.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: X86 ML <x86@kernel.org>, Theodore Ts'o <tytso@mit.edu>,
	Kees Cook <keescook@chromium.org>, kvm list <kvm@vger.kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Gleb Natapov <gleb@kernel.org>, Andrew Honig <ahonig@google.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Linux Virtualization <virtualization@lists.linux-foundation.org>,
	Daniel Borkmann <dborkman@redhat.com>,
	Bandan Das <bsd@redhat.com>,
	Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
	Alok Kataria <akataria@vmware.com>,
	"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: GET_RNG_SEED hypercall ABI? (Re: [PATCH v5 0/5] random,x86,kvm: Rework arch RNG seeds and get some from kvm)
Date: Fri, 29 Aug 2014 08:36:47 +0200	[thread overview]
Message-ID: <54001F7F.5030206@redhat.com> (raw)
In-Reply-To: <CALCETrVW3ZQ7C6F4tab+UrUy=bX4UepPPrhVNrDtLx=ckz2EpA@mail.gmail.com>

Il 29/08/2014 02:13, Andy Lutomirski ha scritto:
> Hmm.  Then, assuming that someone manages to allocate a
> cross-hypervisor MSR number for this, what am I supposed to do in the
> KVM code?  Just make it available unconditionally?  I don't see why
> that wouldn't work reliably, but it seems like an odd design.

The odd part of it is what Gleb mentioned.

> Also, the one and only native feature flag I tested (rdtscp) actually
> does work: RDTSCP seems to send #UD if QEMU is passed -cpu
> host,-rdtscp.

True, and I'm not sure why.  There are a couple others.  I was thinking
more of things like SSE, AVX or DE (that affects the availability of a
bit in CR4).

Paolo

      reply	other threads:[~2014-08-29  6:36 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-26 23:58 GET_RNG_SEED hypercall ABI? (Re: [PATCH v5 0/5] random,x86,kvm: Rework arch RNG seeds and get some from kvm) Andy Lutomirski
2014-08-27  7:00 ` Paolo Bonzini
2014-08-27  7:07   ` H. Peter Anvin
2014-08-28 14:17 ` Gleb Natapov
     [not found] ` <20140828141704.GI18167@minantech.com>
2014-08-28 16:22   ` Andy Lutomirski
2014-08-28 19:46     ` Paolo Bonzini
2014-08-29  0:13       ` Andy Lutomirski
2014-08-29  6:36         ` Paolo Bonzini [this message]

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=54001F7F.5030206@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=ahonig@google.com \
    --cc=akataria@vmware.com \
    --cc=bsd@redhat.com \
    --cc=dborkman@redhat.com \
    --cc=gleb@kernel.org \
    --cc=haiyangz@microsoft.com \
    --cc=hpa@zytor.com \
    --cc=keescook@chromium.org \
    --cc=konrad.wilk@oracle.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=raghavendra.kt@linux.vnet.ibm.com \
    --cc=tytso@mit.edu \
    --cc=vatsa@linux.vnet.ibm.com \
    --cc=virtualization@lists.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;
as well as URLs for NNTP newsgroup(s).