From: Auger Eric <eric.auger@redhat.com>
To: Simon Veith <sveith@amazon.de>,
qemu-devel@nongnu.org, qemu-arm@nongnu.org
Subject: Re: [PATCH 1/5] hw/arm/smmuv3: Apply address mask to linear strtab base address
Date: Mon, 9 Dec 2019 10:14:06 +0100 [thread overview]
Message-ID: <efcd94cb-4397-9004-20d3-950469e30ab7@redhat.com> (raw)
In-Reply-To: <13be5c71-128a-0ae7-1af0-72b58b5958ab@amazon.de>
Hi Simon,
On 12/5/19 11:04 PM, Simon Veith wrote:
> Hello Eric,
>
> On 05/12/2019 09:42, Auger Eric wrote:
>> Not related to this patch but I noticed SMMU_BASE_ADDR_MASK should be
>> 0xffffffffffc0 and not 0xffffffffffe0. I can fix it separately or if you
>> respin, you may fix it as well?
>
> Good catch, thank you. I'll fix it in the next version.
>
> Looking at the upper end of that mask, it seems that we are currently masking out bits 48 through 63, rather than just 51 through 63.
> The reference manual says that this should be done to match the system physical address size as given by SMMU_IDR5.OAS.
Yes you're right. This should go up to 51 as per the field range
definition. Spec says address bits and above this field range are
treated as zero.
>
> We define SMMU_IDR5_OAS to be 4, which selects a physical address size of 44 bits (ref. section 6.3.6). I think the mask should therefore be 0xfffffffffc0 to clear bits 44 and above. Do you agree?
bits beyond the OAS are RES0. The spec does not says those fields are
treated as zero, as explicitly mentioned for bits > 51. Normally the
guest should not set them to something != 0, this would be a programming
error right? Guest is supposed to read the IDR5 and program accordingly?
>
> Ideally, we would derive this mask from our definition of SMMU_IDR5_OAS, but I'm not sure it's okay to stuff a call to oas2bits() into the SMMU_BASE_ADDR_MASK macro.
Well I am not sure this is worth the candle. I am not sure we are
obliged to enforce this.
Thanks
Eric
>
> Regards
> Simon
>
>
>
> Amazon Development Center Germany GmbH
> Krausenstr. 38
> 10117 Berlin
> Geschaeftsfuehrung: Christian Schlaeger, Ralf Herbrich
> Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
> Sitz: Berlin
> Ust-ID: DE 289 237 879
>
>
next prev parent reply other threads:[~2019-12-09 9:15 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-04 13:55 [PATCH 0/5] hw/arm/smmuv3: Correct stream ID and event address handling Simon Veith
2019-12-04 13:55 ` [PATCH 1/5] hw/arm/smmuv3: Apply address mask to linear strtab base address Simon Veith
2019-12-05 8:42 ` Auger Eric
2019-12-05 22:04 ` Simon Veith
2019-12-09 9:14 ` Auger Eric [this message]
2019-12-04 13:55 ` [PATCH 2/5] hw/arm/smmuv3: Check stream IDs against actual table LOG2SIZE Simon Veith
2019-12-05 8:41 ` Auger Eric
2019-12-04 13:55 ` [PATCH 3/5] hw/arm/smmuv3: Align stream table base address to table size Simon Veith
2019-12-05 10:39 ` Auger Eric
2019-12-04 13:55 ` [PATCH 4/5] hw/arm/smmuv3: Use correct bit positions in EVT_SET_ADDR2 macro Simon Veith
2019-12-05 8:37 ` Auger Eric
2019-12-04 13:55 ` [PATCH 5/5] hw/arm/smmuv3: Report F_STE_FETCH fault address in correct word position Simon Veith
2019-12-05 8:39 ` Auger Eric
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=efcd94cb-4397-9004-20d3-950469e30ab7@redhat.com \
--to=eric.auger@redhat.com \
--cc=qemu-arm@nongnu.org \
--cc=qemu-devel@nongnu.org \
--cc=sveith@amazon.de \
/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).