x86/amd-iommu: Protect IOMMU-API map/unmap path
This patch introduces a mutex to lock page table updates in
the IOMMU-API path. We can't use the spin_lock here because
this patch might sleep.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 2c4a501..b97f2f1 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -2327,6 +2327,7 @@
return NULL;
spin_lock_init(&domain->lock);
+ mutex_init(&domain->api_lock);
domain->id = domain_id_alloc();
if (!domain->id)
goto out_err;
@@ -2456,6 +2457,8 @@
iova &= PAGE_MASK;
paddr &= PAGE_MASK;
+ mutex_lock(&domain->api_lock);
+
for (i = 0; i < npages; ++i) {
ret = iommu_map_page(domain, iova, paddr, prot, PM_MAP_4k);
if (ret)
@@ -2465,6 +2468,8 @@
paddr += PAGE_SIZE;
}
+ mutex_unlock(&domain->api_lock);
+
return 0;
}
@@ -2477,12 +2482,16 @@
iova &= PAGE_MASK;
+ mutex_lock(&domain->api_lock);
+
for (i = 0; i < npages; ++i) {
iommu_unmap_page(domain, iova, PM_MAP_4k);
iova += PAGE_SIZE;
}
iommu_flush_tlb_pde(domain);
+
+ mutex_unlock(&domain->api_lock);
}
static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,