From: Lennert Buytenhek <buytenh@wantstofly.org>
To: iommu@lists.linux-foundation.org, Joerg Roedel <joro@8bytes.org>,
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Subject: [PATCH] iommu/amd: Fix I/O page fault logging ratelimit test
Date: Mon, 19 Jul 2021 03:47:19 +0300 [thread overview]
Message-ID: <YPTLl7XHOGp5NiVH@wantstofly.org> (raw)
On an AMD system, I/O page faults are usually logged like this:
drvname 0000:05:00.0: Event logged [IO_PAGE_FAULT domain=0x0000 address=0x0000000092050da0 flags=0x0020]
But sometimes they are logged like this instead, even for the exact
same PCI device:
AMD-Vi: Event logged [IO_PAGE_FAULT device=05:00.0 domain=0x0000 address=0x0000000092050de0 flags=0x0020]
This discrepancy appears to be caused by this code:
if (dev_data && __ratelimit(&dev_data->rs)) {
pci_err(pdev, "Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%llx flags=0x%04x]\n",
domain_id, address, flags);
} else if (printk_ratelimit()) {
pr_err("Event logged [IO_PAGE_FAULT device=%02x:%02x.%x domain=0x%04x address=0x%llx flags=0x%04x]\n",
PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
domain_id, address, flags);
}
If an I/O page fault occurs for a PCI device with associated
iommu_dev_data, but for which the __ratelimit(&dev_data->rs) check fails,
we'll give it a second chance with printk_ratelimit(), and if that check
succeeds, we will log the fault anyway, but in a different format.
Change this to only check printk_ratelimit() if !dev_data, which seems to
be what had been originally intended.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
---
drivers/iommu/amd/iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 811a49a95d04..7ae426b092f2 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -483,7 +483,7 @@ static void amd_iommu_report_page_fault(u16 devid, u16 domain_id,
if (dev_data && __ratelimit(&dev_data->rs)) {
pci_err(pdev, "Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%llx flags=0x%04x]\n",
domain_id, address, flags);
- } else if (printk_ratelimit()) {
+ } else if (!dev_data && printk_ratelimit()) {
pr_err("Event logged [IO_PAGE_FAULT device=%02x:%02x.%x domain=0x%04x address=0x%llx flags=0x%04x]\n",
PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
domain_id, address, flags);
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next reply other threads:[~2021-07-19 0:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-19 0:47 Lennert Buytenhek [this message]
2021-07-21 0:05 ` [PATCH] iommu/amd: Fix I/O page fault logging ratelimit test Suthikulpanit, Suravee via iommu
2021-07-21 13:46 ` Lennert Buytenhek
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