All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jan Beulich <jbeulich@suse.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	Paul Durrant <Paul.Durrant@citrix.com>, Wei Liu <wl@xen.org>,
	Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH v3 2/8] x86/HVM: ignore guest INVD uses
Date: Tue, 3 Sep 2019 14:22:29 +0200	[thread overview]
Message-ID: <f25f8dfa-0b94-deee-1dd3-2f3cf2887a25@suse.com> (raw)
In-Reply-To: <0ff95d72-b647-4dad-40c5-a47a810fc172@citrix.com>

On 03.09.2019 12:18, Andrew Cooper wrote:
> On 03/09/2019 10:37, Jan Beulich wrote:
>> The only place we'd expect the insn to be sensibly used is in
>> (virtualization unaware) firmware.
>>
>> Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> ---
>> v3: New.
>>
>> --- a/xen/arch/x86/hvm/emulate.c
>> +++ b/xen/arch/x86/hvm/emulate.c
>> @@ -2210,11 +2210,18 @@ static int hvmemul_cache_op(
>>  
>>          hvmemul_unmap_linear_addr(mapping, addr, 0, hvmemul_ctxt);
>>          /* fall through */
>> -    case x86emul_invd:
>>      case x86emul_wbinvd:
>>      case x86emul_wbnoinvd:
>>          alternative_vcall(hvm_funcs.wbinvd_intercept);
>>          break;
>> +
>> +    case x86emul_invd:
>> +        /*
>> +         * Deliberately ignored: We don't want to issue INVD, and issuing WBINVD
> 
> I'd phrase this more strongly.  We absolutely must not issue INVD or we
> break cache coherency.
> 
> Ideally with this adjusted, Reviewed-by: Andrew Cooper
> <andrew.cooper3@citrix.com>

Thanks, I've replaced "don't want to" with "mustn't".

Jan

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

  reply	other threads:[~2019-09-03 12:22 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-03  9:35 [Xen-devel] [PATCH v3 0/8] x86emul: further work Jan Beulich
2019-09-03  9:37 ` [Xen-devel] [PATCH v3 1/8] x86emul: support WBNOINVD Jan Beulich
2019-09-03 10:17   ` Andrew Cooper
2019-09-03  9:37 ` [Xen-devel] [PATCH v3 2/8] x86/HVM: ignore guest INVD uses Jan Beulich
2019-09-03  9:43   ` Paul Durrant
2019-09-03 10:18   ` Andrew Cooper
2019-09-03 12:22     ` Jan Beulich [this message]
2019-09-03  9:39 ` [Xen-devel] [PATCH v3 3/8] x86emul: generalize invlpg() hook Jan Beulich
2019-09-03  9:39 ` [Xen-devel] [PATCH v3 4/8] x86emul: support INVPCID Jan Beulich
2019-09-03  9:39 ` [Xen-devel] [PATCH v3 5/8] x86emul: support MOVDIR{I,64B} insns Jan Beulich
2019-09-03 10:28   ` [Xen-devel] [PATCH v3 5/8] x86emul: support MOVDIR{I, 64B} insns Andrew Cooper
2019-09-03 12:25     ` Jan Beulich
2019-09-04 10:19       ` Andrew Cooper
2019-09-04 11:52         ` Jan Beulich
2019-09-03  9:40 ` [Xen-devel] [PATCH v3 6/8] x86/HVM: scale MPERF values reported to guests (on AMD) Jan Beulich
2019-09-03  9:41 ` [Xen-devel] [PATCH v3 7/8] x86emul: support RDPRU Jan Beulich
2019-09-03 12:34   ` Andrew Cooper
2019-09-03 13:05     ` Jan Beulich
2019-09-04  9:26     ` Jan Beulich
2019-09-04  9:46       ` Andrew Cooper
2019-09-03  9:42 ` [Xen-devel] [PATCH v3 8/8] x86/HVM: don't needlessly intercept APERF/MPERF/TSC MSR reads Jan Beulich
2019-09-04 23:16   ` Boris Ostrovsky
2019-09-05  6:31     ` Jan Beulich

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=f25f8dfa-0b94-deee-1dd3-2f3cf2887a25@suse.com \
    --to=jbeulich@suse.com \
    --cc=Paul.Durrant@citrix.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=roger.pau@citrix.com \
    --cc=wl@xen.org \
    --cc=xen-devel@lists.xenproject.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.