Messages in this thread | | | Subject | Re: [PATCH] iommu: check for the deferred attach when attaching a device | From | lijiang <> | Date | Tue, 5 Jan 2021 15:52:06 +0800 |
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在 2021年01月05日 11:55, lijiang 写道: > Hi, > > Also add Joerg to cc list. >
Also add more people to cc list, Jerry Snitselaar and Tom Lendacky.
Thanks.
> Thanks. > Lianbo > 在 2020年12月26日 13:39, Lianbo Jiang 写道: >> Currently, because domain attach allows to be deferred from iommu >> driver to device driver, and when iommu initializes, the devices >> on the bus will be scanned and the default groups will be allocated. >> >> Due to the above changes, some devices could be added to the same >> group as below: >> >> [ 3.859417] pci 0000:01:00.0: Adding to iommu group 16 >> [ 3.864572] pci 0000:01:00.1: Adding to iommu group 16 >> [ 3.869738] pci 0000:02:00.0: Adding to iommu group 17 >> [ 3.874892] pci 0000:02:00.1: Adding to iommu group 17 >> >> But when attaching these devices, it doesn't allow that a group has >> more than one device, otherwise it will return an error. This conflicts >> with the deferred attaching. Unfortunately, it has two devices in the >> same group for my side, for example: >> >> [ 9.627014] iommu_group_device_count(): device name[0]:0000:01:00.0 >> [ 9.633545] iommu_group_device_count(): device name[1]:0000:01:00.1 >> ... >> [ 10.255609] iommu_group_device_count(): device name[0]:0000:02:00.0 >> [ 10.262144] iommu_group_device_count(): device name[1]:0000:02:00.1 >> >> Finally, which caused the failure of tg3 driver when tg3 driver calls >> the dma_alloc_coherent() to allocate coherent memory in the tg3_test_dma(). >> >> [ 9.660310] tg3 0000:01:00.0: DMA engine test failed, aborting >> [ 9.754085] tg3: probe of 0000:01:00.0 failed with error -12 >> [ 9.997512] tg3 0000:01:00.1: DMA engine test failed, aborting >> [ 10.043053] tg3: probe of 0000:01:00.1 failed with error -12 >> [ 10.288905] tg3 0000:02:00.0: DMA engine test failed, aborting >> [ 10.334070] tg3: probe of 0000:02:00.0 failed with error -12 >> [ 10.578303] tg3 0000:02:00.1: DMA engine test failed, aborting >> [ 10.622629] tg3: probe of 0000:02:00.1 failed with error -12 >> >> In addition, the similar situations also occur in other drivers such >> as the bnxt_en driver. That can be reproduced easily in kdump kernel >> when SME is active. >> >> Add a check for the deferred attach in the iommu_attach_device() and >> allow to attach the deferred device regardless of how many devices >> are in a group. >> >> Signed-off-by: Lianbo Jiang <lijiang@redhat.com> >> --- >> drivers/iommu/iommu.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >> index ffeebda8d6de..dccab7b133fb 100644 >> --- a/drivers/iommu/iommu.c >> +++ b/drivers/iommu/iommu.c >> @@ -1967,8 +1967,11 @@ int iommu_attach_device(struct iommu_domain *domain, struct device *dev) >> */ >> mutex_lock(&group->mutex); >> ret = -EINVAL; >> - if (iommu_group_device_count(group) != 1) >> + if (!iommu_is_attach_deferred(domain, dev) && >> + iommu_group_device_count(group) != 1) { >> + dev_err_ratelimited(dev, "Group has more than one device\n"); >> goto out_unlock; >> + } >> >> ret = __iommu_attach_group(domain, group); >> >>
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