From: Janosch Frank <frankja@linux.ibm.com>
To: David Hildenbrand <david@redhat.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
kvm@vger.kernel.org
Cc: cohuck@redhat.com, borntraeger@de.ibm.com, thuth@redhat.com,
pasic@linux.ibm.com, linux-s390@vger.kernel.org,
linux-kernel@vger.kernel.org, Ulrich.Weigand@de.ibm.com
Subject: Re: [PATCH v3 01/14] KVM: s390: pv: add macros for UVC CC values
Date: Fri, 6 Aug 2021 17:15:46 +0200 [thread overview]
Message-ID: <54a3b55e-bf05-e661-0618-7839f3d2c8dd@linux.ibm.com> (raw)
In-Reply-To: <f3fc81a7-ea71-56f6-16e0-e43fc36d646e@redhat.com>
On 8/6/21 9:26 AM, David Hildenbrand wrote:
> On 04.08.21 17:40, Claudio Imbrenda wrote:
>> Add macros to describe the 4 possible CC values returned by the UVC
>> instruction.
>>
>> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
>> ---
>> arch/s390/include/asm/uv.h | 5 +++++
>> 1 file changed, 5 insertions(+)
>>
>> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
>> index 12c5f006c136..b35add51b967 100644
>> --- a/arch/s390/include/asm/uv.h
>> +++ b/arch/s390/include/asm/uv.h
>> @@ -18,6 +18,11 @@
>> #include <asm/page.h>
>> #include <asm/gmap.h>
>>
>> +#define UVC_CC_OK 0
>> +#define UVC_CC_ERROR 1
>> +#define UVC_CC_BUSY 2
>> +#define UVC_CC_PARTIAL 3
>> +
>> #define UVC_RC_EXECUTED 0x0001
>> #define UVC_RC_INV_CMD 0x0002
>> #define UVC_RC_INV_STATE 0x0003
>>
>
> Do we have any users we could directly fix up? AFAIKs, most users don't
> really care about the cc value, only about cc vs !cc.
>
> The only instances I was able to spot quickly:
The only fix for the functions below that I would accept would be to
check for cc 2 and 3. A cc >= UVC_CC_BUSY confuses me way too much when
reading.
But honestly for those two I'd just keep the code as is. I only asked
Claudio to fix the code in the next patch and add this patch as it was
not clearly visible he was dealing with a CC.
>
>
> diff --git a/arch/s390/include/asm/uv.h b/arch/s390/include/asm/uv.h
> index 12c5f006c136..dd72d325f9e8 100644
> --- a/arch/s390/include/asm/uv.h
> +++ b/arch/s390/include/asm/uv.h
> @@ -233,7 +233,7 @@ static inline int uv_call(unsigned long r1, unsigned
> long r2)
>
> do {
> cc = __uv_call(r1, r2);
> - } while (cc > 1);
> + } while (cc >= UVC_CC_BUSY);
> return cc;
> }
>
> @@ -245,7 +245,7 @@ static inline int uv_call_sched(unsigned long r1,
> unsigned long r2)
> do {
> cc = __uv_call(r1, r2);
> cond_resched();
> - } while (cc > 1);
> + } while (cc >= UVC_CC_BUSY);
> return cc;
> }
>
>
> Of course, we could replace all checks for cc vs !cc with "cc !=
> UVC_CC_OK" vs "cc == UVC_CC_OK".
>
next prev parent reply other threads:[~2021-08-06 15:15 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-04 15:40 [PATCH v3 00/14] KVM: s390: pv: implement lazy destroy Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 01/14] KVM: s390: pv: add macros for UVC CC values Claudio Imbrenda
2021-08-06 7:26 ` David Hildenbrand
2021-08-06 9:34 ` Claudio Imbrenda
2021-08-06 15:15 ` Janosch Frank [this message]
2021-08-04 15:40 ` [PATCH v3 02/14] KVM: s390: pv: avoid stall notifications for some UVCs Claudio Imbrenda
2021-08-06 7:30 ` David Hildenbrand
2021-08-06 9:33 ` Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 03/14] KVM: s390: pv: leak the ASCE page when destroy fails Claudio Imbrenda
2021-08-06 7:31 ` David Hildenbrand
2021-08-06 9:32 ` Claudio Imbrenda
2021-08-06 11:39 ` David Hildenbrand
2021-08-04 15:40 ` [PATCH v3 04/14] KVM: s390: pv: properly handle page flags for protected guests Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 05/14] KVM: s390: pv: handle secure storage violations " Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 06/14] KVM: s390: pv: handle secure storage exceptions for normal guests Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 07/14] KVM: s390: pv: refactor s390_reset_acc Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 08/14] KVM: s390: pv: usage counter instead of flag Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 09/14] KVM: s390: pv: add export before import Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 10/14] KVM: s390: pv: lazy destroy for reboot Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 11/14] KVM: s390: pv: extend lazy destroy to handle shutdown Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 12/14] KVM: s390: pv: module parameter to fence lazy destroy Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 13/14] KVM: s390: pv: add OOM notifier for " Claudio Imbrenda
2021-08-04 15:40 ` [PATCH v3 14/14] KVM: s390: pv: avoid export before import if possible Claudio Imbrenda
2021-08-06 7:10 ` [PATCH v3 00/14] KVM: s390: pv: implement lazy destroy David Hildenbrand
2021-08-06 9:30 ` Claudio Imbrenda
2021-08-06 11:30 ` David Hildenbrand
2021-08-06 13:44 ` Claudio Imbrenda
2021-08-09 8:50 ` David Hildenbrand
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=54a3b55e-bf05-e661-0618-7839f3d2c8dd@linux.ibm.com \
--to=frankja@linux.ibm.com \
--cc=Ulrich.Weigand@de.ibm.com \
--cc=borntraeger@de.ibm.com \
--cc=cohuck@redhat.com \
--cc=david@redhat.com \
--cc=imbrenda@linux.ibm.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=pasic@linux.ibm.com \
--cc=thuth@redhat.com \
/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).