All of lore.kernel.org
 help / color / mirror / Atom feed
From: Joerg Roedel <joro@8bytes.org>
To: Nadav Amit <namit@vmware.com>
Cc: Will Deacon <will@kernel.org>, Jiajun Cao <caojiajun@vmware.com>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] iommu/amd: page-specific invalidations for more than one page
Date: Thu, 8 Apr 2021 15:23:49 +0200	[thread overview]
Message-ID: <YG8D5ZjSxZm6tF9v@8bytes.org> (raw)
In-Reply-To: <80A4A5F2-5D8C-4F8D-BF7B-CFFF4F770F57@vmware.com>

On Thu, Apr 08, 2021 at 10:29:25AM +0000, Nadav Amit wrote:
> In the version that you referred me to, iommu_update_domain_tlb() only
> regards the size of the region to be flushed and disregards the
> alignment:
> 
> +	order   = get_order(domain->flush.end - domain->flush.start);
> +	mask    = (0x1000ULL << order) - 1;
> +	address = ((domain->flush.start & ~mask) | (mask >> 1)) & ~0xfffULL;
> 
> 
> If you need to flush for instance the region between 0x1000-0x5000, this
> version would use the address|mask of 0x1000 (16KB page). The version I
> sent regards the alignment, and since the range is not aligned would use
> address|mask of 0x3000 (32KB page).
> 
> IIUC, IOVA allocations today are aligned in such way, but at least in
> the past (looking on 3.19 for the matter), it was not like always like
> that, which can explain the problems.

Yeah, that make sense and explains the data corruption problems. I will
give your patch a try on one of my test machines and consider it for
v5.13 if all goes well.

Thanks,

	Joerg

WARNING: multiple messages have this Message-ID (diff)
From: Joerg Roedel <joro@8bytes.org>
To: Nadav Amit <namit@vmware.com>
Cc: "iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>, Will Deacon <will@kernel.org>,
	Jiajun Cao <caojiajun@vmware.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] iommu/amd: page-specific invalidations for more than one page
Date: Thu, 8 Apr 2021 15:23:49 +0200	[thread overview]
Message-ID: <YG8D5ZjSxZm6tF9v@8bytes.org> (raw)
In-Reply-To: <80A4A5F2-5D8C-4F8D-BF7B-CFFF4F770F57@vmware.com>

On Thu, Apr 08, 2021 at 10:29:25AM +0000, Nadav Amit wrote:
> In the version that you referred me to, iommu_update_domain_tlb() only
> regards the size of the region to be flushed and disregards the
> alignment:
> 
> +	order   = get_order(domain->flush.end - domain->flush.start);
> +	mask    = (0x1000ULL << order) - 1;
> +	address = ((domain->flush.start & ~mask) | (mask >> 1)) & ~0xfffULL;
> 
> 
> If you need to flush for instance the region between 0x1000-0x5000, this
> version would use the address|mask of 0x1000 (16KB page). The version I
> sent regards the alignment, and since the range is not aligned would use
> address|mask of 0x3000 (32KB page).
> 
> IIUC, IOVA allocations today are aligned in such way, but at least in
> the past (looking on 3.19 for the matter), it was not like always like
> that, which can explain the problems.

Yeah, that make sense and explains the data corruption problems. I will
give your patch a try on one of my test machines and consider it for
v5.13 if all goes well.

Thanks,

	Joerg
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  reply	other threads:[~2021-04-08 13:23 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-23 21:06 [PATCH] iommu/amd: page-specific invalidations for more than one page Nadav Amit
2021-03-23 21:06 ` Nadav Amit
2021-04-07 10:01 ` Joerg Roedel
2021-04-07 10:01   ` Joerg Roedel
2021-04-07 17:57   ` Nadav Amit
2021-04-07 17:57     ` Nadav Amit
2021-04-08  7:18     ` Joerg Roedel
2021-04-08  7:18       ` Joerg Roedel
2021-04-08 10:29       ` Nadav Amit
2021-04-08 10:29         ` Nadav Amit
2021-04-08 13:23         ` Joerg Roedel [this message]
2021-04-08 13:23           ` Joerg Roedel
2021-04-08 15:16 ` Joerg Roedel
2021-04-08 15:16   ` Joerg Roedel

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=YG8D5ZjSxZm6tF9v@8bytes.org \
    --to=joro@8bytes.org \
    --cc=caojiajun@vmware.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=namit@vmware.com \
    --cc=will@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 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.