From: Thiago Jung Bauermann <bauerman@linux.ibm.com>
To: Christoph Hellwig <hch@lst.de>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
Alexey Kardashevskiy <aik@ozlabs.ru>,
Anshuman Khandual <anshuman.linux@gmail.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Mike Anderson <andmike@linux.ibm.com>,
Paul Mackerras <paulus@samba.org>, Ram Pai <linuxram@us.ibm.com>,
Claudio Carvalho <cclaudio@linux.ibm.com>
Subject: Re: [PATCH v3 13/16] powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests
Date: Tue, 06 Aug 2019 22:37:34 -0300 [thread overview]
Message-ID: <87k1bpzrfl.fsf@morokweng.localdomain> (raw)
In-Reply-To: <20190806054841.GA14197@lst.de>
Hello Christoph,
Thanks for your review.
Christoph Hellwig <hch@lst.de> writes:
> On Tue, Aug 06, 2019 at 02:22:34AM -0300, Thiago Jung Bauermann wrote:
>> @@ -1318,7 +1319,10 @@ void iommu_init_early_pSeries(void)
>> of_reconfig_notifier_register(&iommu_reconfig_nb);
>> register_memory_notifier(&iommu_mem_nb);
>>
>> - set_pci_dma_ops(&dma_iommu_ops);
>> + if (is_secure_guest())
>> + set_pci_dma_ops(NULL);
>> + else
>> + set_pci_dma_ops(&dma_iommu_ops);
>
> Shoudn't:
>
> if (!is_secure_guest())
> set_pci_dma_ops(&dma_iommu_ops);
>
> be enough here, given that NULL is the default?
Indeed, it is enough.
> Also either way I think this conditional needs a comment explaining
> why it is there.
Good point. I added the commit message as a comment in the code.
New version of this patch below.
From 5dc3914efa4765eef2869d554d4ea1c676bb1e75 Mon Sep 17 00:00:00 2001
From: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Date: Thu, 24 Jan 2019 22:40:16 -0200
Subject: [PATCH] powerpc/pseries/iommu: Don't use dma_iommu_ops on secure
guests
Secure guest memory is inacessible to devices so regular DMA isn't
possible.
In that case set devices' dma_map_ops to NULL so that the generic
DMA code path will use SWIOTLB to bounce buffers for DMA.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
---
arch/powerpc/platforms/pseries/iommu.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 889dc2e44b89..8d9c2b17ad54 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -36,6 +36,7 @@
#include <asm/udbg.h>
#include <asm/mmzone.h>
#include <asm/plpar_wrappers.h>
+#include <asm/svm.h>
#include "pseries.h"
@@ -1318,7 +1319,15 @@ void iommu_init_early_pSeries(void)
of_reconfig_notifier_register(&iommu_reconfig_nb);
register_memory_notifier(&iommu_mem_nb);
- set_pci_dma_ops(&dma_iommu_ops);
+ /*
+ * Secure guest memory is inacessible to devices so regular DMA isn't
+ * possible.
+ *
+ * In that case keep devices' dma_map_ops as NULL so that the generic
+ * DMA code path will use SWIOTLB to bounce buffers for DMA.
+ */
+ if (!is_secure_guest())
+ set_pci_dma_ops(&dma_iommu_ops);
}
static int __init disable_multitce(char *str)
next prev parent reply other threads:[~2019-08-07 1:38 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-06 5:22 [PATCH v3 00/16] Secure Virtual Machine Enablement Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 01/16] powerpc/kernel: Add ucall_norets() ultravisor call handler Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 02/16] powerpc/pseries: Introduce option to build secure virtual machines Thiago Jung Bauermann
2019-08-06 5:22 ` [RFC PATCH v3 03/16] powerpc: Add support for adding an ESM blob to the zImage wrapper Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 04/16] powerpc/prom_init: Add the ESM call to prom_init Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 05/16] powerpc/pseries/svm: Add helpers for UV_SHARE_PAGE and UV_UNSHARE_PAGE Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 06/16] powerpc: Introduce the MSR_S bit Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 07/16] powerpc/pseries: Add and use LPPACA_SIZE constant Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 08/16] powerpc/pseries/svm: Use shared memory for LPPACA structures Thiago Jung Bauermann
2019-08-12 12:36 ` Michael Ellerman
2019-08-12 21:43 ` Thiago Jung Bauermann
2019-08-14 10:54 ` Michael Ellerman
2019-08-16 0:52 ` Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 09/16] powerpc/pseries/svm: Use shared memory for Debug Trace Log (DTL) Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 10/16] powerpc/pseries/svm: Unshare all pages before kexecing a new kernel Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 11/16] powerpc/pseries/svm: Export guest SVM status to user space via sysfs Thiago Jung Bauermann
2019-08-12 13:03 ` Michael Ellerman
2019-08-12 23:21 ` Thiago Jung Bauermann
2019-08-15 6:30 ` Michael Ellerman
2019-08-16 0:49 ` Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 12/16] powerpc/pseries/svm: Disable doorbells in SVM guests Thiago Jung Bauermann
2019-08-06 5:22 ` [PATCH v3 13/16] powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests Thiago Jung Bauermann
2019-08-06 5:48 ` Christoph Hellwig
2019-08-07 1:37 ` Thiago Jung Bauermann [this message]
2019-08-06 5:22 ` [PATCH v3 14/16] powerpc/pseries/svm: Force SWIOTLB for " Thiago Jung Bauermann
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=87k1bpzrfl.fsf@morokweng.localdomain \
--to=bauerman@linux.ibm.com \
--cc=aik@ozlabs.ru \
--cc=andmike@linux.ibm.com \
--cc=anshuman.linux@gmail.com \
--cc=benh@kernel.crashing.org \
--cc=cclaudio@linux.ibm.com \
--cc=hch@lst.de \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=linuxram@us.ibm.com \
--cc=mpe@ellerman.id.au \
--cc=paulus@samba.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).