From: "Jürgen Groß" <jgross@suse.com>
To: peng.fan@nxp.com, konrad.wilk@oracle.com,
boris.ostrovsky@oracle.com, sstabellini@kernel.org
Cc: xen-devel@lists.xenproject.org, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org, linux-imx@nxp.com
Subject: Re: [PATCH] xen/swiotlb: correct the check for xen_destroy_contiguous_region
Date: Tue, 28 Apr 2020 10:09:08 +0200 [thread overview]
Message-ID: <1c01e97a-adcd-a703-55b5-8975b4ce4d2c@suse.com> (raw)
In-Reply-To: <1588059225-11245-1-git-send-email-peng.fan@nxp.com>
On 28.04.20 09:33, peng.fan@nxp.com wrote:
> From: Peng Fan <peng.fan@nxp.com>
>
> When booting xen on i.MX8QM, met:
> "
> [ 3.602128] Unable to handle kernel paging request at virtual address 0000000000272d40
> [ 3.610804] Mem abort info:
> [ 3.613905] ESR = 0x96000004
> [ 3.617332] EC = 0x25: DABT (current EL), IL = 32 bits
> [ 3.623211] SET = 0, FnV = 0
> [ 3.626628] EA = 0, S1PTW = 0
> [ 3.630128] Data abort info:
> [ 3.633362] ISV = 0, ISS = 0x00000004
> [ 3.637630] CM = 0, WnR = 0
> [ 3.640955] [0000000000272d40] user address but active_mm is swapper
> [ 3.647983] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> [ 3.654137] Modules linked in:
> [ 3.677285] Hardware name: Freescale i.MX8QM MEK (DT)
> [ 3.677302] Workqueue: events deferred_probe_work_func
> [ 3.684253] imx6q-pcie 5f000000.pcie: PCI host bridge to bus 0000:00
> [ 3.688297] pstate: 60000005 (nZCv daif -PAN -UAO)
> [ 3.688310] pc : xen_swiotlb_free_coherent+0x180/0x1c0
> [ 3.693993] pci_bus 0000:00: root bus resource [bus 00-ff]
> [ 3.701002] lr : xen_swiotlb_free_coherent+0x44/0x1c0
> "
>
> In xen_swiotlb_alloc_coherent, if !(dev_addr + size - 1 <= dma_mask) or
> range_straddles_page_boundary(phys, size) are true, it will
> create contiguous region. So when free, we need to free contiguous
> region use upper check condition.
No, this will break PV guests on x86.
I think there is something wrong with your setup in combination with
the ARM xen_create_contiguous_region() implementation.
Stefano?
Juergen
>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
> drivers/xen/swiotlb-xen.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
> index b6d27762c6f8..ab96e468584f 100644
> --- a/drivers/xen/swiotlb-xen.c
> +++ b/drivers/xen/swiotlb-xen.c
> @@ -346,8 +346,8 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
> /* Convert the size to actually allocated. */
> size = 1UL << (order + XEN_PAGE_SHIFT);
>
> - if (!WARN_ON((dev_addr + size - 1 > dma_mask) ||
> - range_straddles_page_boundary(phys, size)) &&
> + if (((dev_addr + size - 1 > dma_mask) ||
> + range_straddles_page_boundary(phys, size)) &&
> TestClearPageXenRemapped(virt_to_page(vaddr)))
> xen_destroy_contiguous_region(phys, order);
>
>
next prev parent reply other threads:[~2020-04-28 8:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 7:33 [PATCH] xen/swiotlb: correct the check for xen_destroy_contiguous_region peng.fan
2020-04-28 8:02 ` Christoph Hellwig
2020-04-28 8:21 ` Peng Fan
2020-04-28 8:09 ` Jürgen Groß [this message]
2020-04-28 8:25 ` Peng Fan
2020-04-28 10:19 ` Jürgen Groß
2020-04-28 17:25 ` Konrad Rzeszutek Wilk
2020-04-28 18:37 ` Joe Jin
2020-04-28 18:46 ` Stefano Stabellini
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=1c01e97a-adcd-a703-55b5-8975b4ce4d2c@suse.com \
--to=jgross@suse.com \
--cc=boris.ostrovsky@oracle.com \
--cc=iommu@lists.linux-foundation.org \
--cc=konrad.wilk@oracle.com \
--cc=linux-imx@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=peng.fan@nxp.com \
--cc=sstabellini@kernel.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 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).