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authorJean-Philippe Brucker <jean-philippe@linaro.org>2020-06-16 16:47:14 +0200
committerJoerg Roedel <jroedel@suse.de>2020-06-30 11:49:21 +0200
commit970471914c67b70df24def6b2a30cc42acbebded (patch)
treee5a47d0fc2c463cc17aa7f2f55f25a10fc6a8948 /include/uapi/linux/iommu.h
parentd3e3d2be688b4b5864538de61e750721a311e4fc (diff)
iommu: Allow page responses without PASID
Some PCIe devices do not expect a PASID value in PRI Page Responses. If the "PRG Response PASID Required" bit in the PRI capability is zero, then the OS should not set the PASID field. Similarly on Arm SMMU, responses to stall events do not have a PASID. Currently iommu_page_response() systematically checks that the PASID in the page response corresponds to the one in the page request. This can't work with virtualization because a page response coming from a guest OS won't have a PASID if the passed-through device does not require one. Add a flag to page requests that declares whether the corresponding response needs to have a PASID. When this flag isn't set, allow page responses without PASID. Reported-by: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Link: https://lore.kernel.org/r/20200616144712.748818-1-jean-philippe@linaro.org Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'include/uapi/linux/iommu.h')
-rw-r--r--include/uapi/linux/iommu.h6
1 files changed, 5 insertions, 1 deletions
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
index e907b7091a46..c2b2caf9ed41 100644
--- a/include/uapi/linux/iommu.h
+++ b/include/uapi/linux/iommu.h
@@ -81,7 +81,10 @@ struct iommu_fault_unrecoverable {
/**
* struct iommu_fault_page_request - Page Request data
* @flags: encodes whether the corresponding fields are valid and whether this
- * is the last page in group (IOMMU_FAULT_PAGE_REQUEST_* values)
+ * is the last page in group (IOMMU_FAULT_PAGE_REQUEST_* values).
+ * When IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID is set, the page response
+ * must have the same PASID value as the page request. When it is clear,
+ * the page response should not have a PASID.
* @pasid: Process Address Space ID
* @grpid: Page Request Group Index
* @perm: requested page permissions (IOMMU_FAULT_PERM_* values)
@@ -92,6 +95,7 @@ struct iommu_fault_page_request {
#define IOMMU_FAULT_PAGE_REQUEST_PASID_VALID (1 << 0)
#define IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE (1 << 1)
#define IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA (1 << 2)
+#define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID (1 << 3)
__u32 flags;
__u32 pasid;
__u32 grpid;