linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v3 ] iommu/vt-d: Fix panic after kexec -p for kdump
@ 2019-10-22  2:48 John Donnelly
  2019-10-30  9:33 ` Joerg Roedel
  0 siblings, 1 reply; 3+ messages in thread
From: John Donnelly @ 2019-10-22  2:48 UTC (permalink / raw)
  To: linux-kernel; +Cc: Lu Baolu, joro, John Donnelly



This cures a panic on restart after a kexec operation on 5.3 and 5.4 
kernels.

The underlying state of the iommu registers (iommu->flags &
VTD_FLAG_TRANS_PRE_ENABLED) on a restart results in a domain being marked as
"DEFER_DEVICE_DOMAIN_INFO" that produces an Oops in identity_mapping().

[   43.654737] BUG: kernel NULL pointer dereference, address:
0000000000000056
[   43.655720] #PF: supervisor read access in kernel mode
[   43.655720] #PF: error_code(0x0000) - not-present page
[   43.655720] PGD 0 P4D 0
[   43.655720] Oops: 0000 [#1] SMP PTI
[   43.655720] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
5.3.2-1940.el8uek.x86_64 #1
[   43.655720] Hardware name: Oracle Corporation ORACLE SERVER
X5-2/ASM,MOTHERBOARD,1U, BIOS 30140300 09/20/2018
[   43.655720] RIP: 0010:iommu_need_mapping+0x29/0xd0
[   43.655720] Code: 00 0f 1f 44 00 00 48 8b 97 70 02 00 00 48 83 fa ff
74 53 48 8d 4a ff b8 01 00 00 00 48 83 f9 fd 76 01 c3 48 8b 35 7f 58 e0
01 <48> 39 72 58 75 f2 55 48 89 e5 41 54 53 48 8b 87 28 02 00 00 4c 8b
[   43.655720] RSP: 0018:ffffc9000001b9b0 EFLAGS: 00010246
[   43.655720] RAX: 0000000000000001 RBX: 0000000000001000 RCX:
fffffffffffffffd
[   43.655720] RDX: fffffffffffffffe RSI: ffff8880719b8000 RDI:
ffff8880477460b0
[   43.655720] RBP: ffffc9000001b9e8 R08: 0000000000000000 R09:
ffff888047c01700
[   43.655720] R10: 00002194036fc692 R11: 0000000000000000 R12:
0000000000000000
[   43.655720] R13: ffff8880477460b0 R14: 0000000000000cc0 R15:
ffff888072d2b558
[   43.655720] FS:  0000000000000000(0000) GS:ffff888071c00000(0000)
knlGS:0000000000000000
[   43.655720] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   43.655720] CR2: 0000000000000056 CR3: 000000007440a002 CR4:
00000000001606b0
[   43.655720] Call Trace:
[   43.655720]  ? intel_alloc_coherent+0x2a/0x180
[   43.655720]  ? __schedule+0x2c2/0x650
[   43.655720]  dma_alloc_attrs+0x8c/0xd0
[   43.655720]  dma_pool_alloc+0xdf/0x200
[   43.655720]  ehci_qh_alloc+0x58/0x130
[   43.655720]  ehci_setup+0x287/0x7ba
[   43.655720]  ? _dev_info+0x6c/0x83
[   43.655720]  ehci_pci_setup+0x91/0x436
[   43.655720]  usb_add_hcd.cold.48+0x1d4/0x754
[   43.655720]  usb_hcd_pci_probe+0x2bc/0x3f0
[   43.655720]  ehci_pci_probe+0x39/0x40
[   43.655720]  local_pci_probe+0x47/0x80
[   43.655720]  pci_device_probe+0xff/0x1b0
[   43.655720]  really_probe+0xf5/0x3a0
[   43.655720]  driver_probe_device+0xbb/0x100
[   43.655720]  device_driver_attach+0x58/0x60
[   43.655720]  __driver_attach+0x8f/0x150
[   43.655720]  ? device_driver_attach+0x60/0x60
[   43.655720]  bus_for_each_dev+0x74/0xb0
[   43.655720]  driver_attach+0x1e/0x20
[   43.655720]  bus_add_driver+0x151/0x1f0
[   43.655720]  ? ehci_hcd_init+0xb2/0xb2
[   43.655720]  ? do_early_param+0x95/0x95
[   43.655720]  driver_register+0x70/0xc0
[   43.655720]  ? ehci_hcd_init+0xb2/0xb2
[   43.655720]  __pci_register_driver+0x57/0x60
[   43.655720]  ehci_pci_init+0x6a/0x6c
[   43.655720]  do_one_initcall+0x4a/0x1fa
[   43.655720]  ? do_early_param+0x95/0x95
[   43.655720]  kernel_init_freeable+0x1bd/0x262
[   43.655720]  ? rest_init+0xb0/0xb0
[   43.655720]  kernel_init+0xe/0x110
[   43.655720]  ret_from_fork+0x24/0x50


Fixes: 8af46c784ecfe ("iommu/vt-d: Implement is_attach_deferred iommu 
ops entry")
Cc: stable@vger.kernel.org # v5.3+

Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>


---
  drivers/iommu/intel-iommu.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index c4e0e4a9ee9e..f83a9a302f8e 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -2783,7 +2783,7 @@ static int identity_mapping(struct device *dev)
  	struct device_domain_info *info;

  	info = dev->archdata.iommu;
-	if (info && info != DUMMY_DEVICE_DOMAIN_INFO)
+	if (info && info != DUMMY_DEVICE_DOMAIN_INFO && info != 
DEFER_DEVICE_DOMAIN_INFO)
  		return (info->domain == si_domain);

  	return 0;
-- 
2.20.1


-- 
Thank You,
John

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v3 ] iommu/vt-d: Fix panic after kexec -p for kdump
  2019-10-22  2:48 [PATCH v3 ] iommu/vt-d: Fix panic after kexec -p for kdump John Donnelly
@ 2019-10-30  9:33 ` Joerg Roedel
  2019-10-30 13:01   ` John Donnelly
  0 siblings, 1 reply; 3+ messages in thread
From: Joerg Roedel @ 2019-10-30  9:33 UTC (permalink / raw)
  To: John Donnelly; +Cc: linux-kernel, Lu Baolu

Hi John,

On Mon, Oct 21, 2019 at 09:48:10PM -0500, John Donnelly wrote:
> Fixes: 8af46c784ecfe ("iommu/vt-d: Implement is_attach_deferred iommu ops
> entry")
> Cc: stable@vger.kernel.org # v5.3+
> 
> Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
> 
> 
> ---
>  drivers/iommu/intel-iommu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index c4e0e4a9ee9e..f83a9a302f8e 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -2783,7 +2783,7 @@ static int identity_mapping(struct device *dev)
>  	struct device_domain_info *info;
> 
>  	info = dev->archdata.iommu;
> -	if (info && info != DUMMY_DEVICE_DOMAIN_INFO)
> +	if (info && info != DUMMY_DEVICE_DOMAIN_INFO && info !=
> DEFER_DEVICE_DOMAIN_INFO)
>  		return (info->domain == si_domain);
> 
>  	return 0;

I applied your patch for v5.4, but it needed manual fixup because your
mailer screwed up the patch format by inserting line-breaks and
converting tabs to spaces.

Please consider to setup and use 'git send-email' for your next patches.
This will get it all right and makes life easier for maintainers that
want to apply your patches.

Thanks,

	Joerg

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v3 ] iommu/vt-d: Fix panic after kexec -p for kdump
  2019-10-30  9:33 ` Joerg Roedel
@ 2019-10-30 13:01   ` John Donnelly
  0 siblings, 0 replies; 3+ messages in thread
From: John Donnelly @ 2019-10-30 13:01 UTC (permalink / raw)
  To: Joerg Roedel; +Cc: linux-kernel, Lu Baolu

On 10/30/19 4:33 AM, Joerg Roedel wrote:
> Hi John,
> 
> On Mon, Oct 21, 2019 at 09:48:10PM -0500, John Donnelly wrote:
>> Fixes: 8af46c784ecfe ("iommu/vt-d: Implement is_attach_deferred iommu ops
>> entry")
>> Cc: stable@vger.kernel.org # v5.3+
>>
>> Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
>> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
>>
>>
>> ---
>>   drivers/iommu/intel-iommu.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
>> index c4e0e4a9ee9e..f83a9a302f8e 100644
>> --- a/drivers/iommu/intel-iommu.c
>> +++ b/drivers/iommu/intel-iommu.c
>> @@ -2783,7 +2783,7 @@ static int identity_mapping(struct device *dev)
>>   	struct device_domain_info *info;
>>
>>   	info = dev->archdata.iommu;
>> -	if (info && info != DUMMY_DEVICE_DOMAIN_INFO)
>> +	if (info && info != DUMMY_DEVICE_DOMAIN_INFO && info !=
>> DEFER_DEVICE_DOMAIN_INFO)
>>   		return (info->domain == si_domain);
>>
>>   	return 0;
> 
> I applied your patch for v5.4, but it needed manual fixup because your
> mailer screwed up the patch format by inserting line-breaks and
> converting tabs to spaces.
> 
> Please consider to setup and use 'git send-email' for your next patches.
> This will get it all right and makes life easier for maintainers that
> want to apply your patches.
> 
> Thanks,
> 
> 	Joerg
> 
Thank you .

I tried using the git mailer from my development server but 
vger.kernel.org mailer rejected it because the generated email did not 
match the subscription email and was rejected.





-- 
Thank You,
John

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-10-30 13:02 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-22  2:48 [PATCH v3 ] iommu/vt-d: Fix panic after kexec -p for kdump John Donnelly
2019-10-30  9:33 ` Joerg Roedel
2019-10-30 13:01   ` John Donnelly

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).