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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging-4.12] x86 / iommu: set up a scratch page in the quarantine domain
commit 1e8932f0d815bee3102ede328676e1a4ca1926c7
Author: Paul Durrant <pdurrant@xxxxxxxxxx>
AuthorDate: Fri Dec 6 12:46:24 2019 +0100
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Dec 6 12:46:24 2019 +0100
x86 / iommu: set up a scratch page in the quarantine domain
This patch introduces a new iommu_op to facilitate a per-implementation
quarantine set up, and then further code for x86 implementations
(amd and vtd) to set up a read-only scratch page to serve as the source
for DMA reads whilst a device is assigned to dom_io. DMA writes will
continue to fault as before.
The reason for doing this is that some hardware may continue to re-try
DMA (despite FLR) in the event of an error, or even BME being cleared, and
will fail to deal with DMA read faults gracefully. Having a scratch page
mapped will allow pending DMA reads to complete and thus such buggy
hardware will eventually be quiesced.
NOTE: These modifications are restricted to x86 implementations only as
the buggy h/w I am aware of is only used with Xen in an x86
environment. ARM may require similar code but, since I am not
aware of the need, this patch does not modify any ARM implementation.
Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
master commit: ea38867831da67eed0e9c61672c8941016b63dd9
master date: 2019-11-29 18:27:54 +0000
---
xen/drivers/passthrough/amd/iommu_map.c | 62 ++++++++++++++++++++++
xen/drivers/passthrough/amd/pci_amd_iommu.c | 14 ++---
xen/drivers/passthrough/iommu.c | 17 +++++-
xen/drivers/passthrough/vtd/iommu.c | 74 ++++++++++++++++++++++-----
xen/include/asm-x86/hvm/svm/amd-iommu-proto.h | 3 ++
xen/include/xen/iommu.h | 1 +
6 files changed, 147 insertions(+), 24 deletions(-)
diff --git a/xen/drivers/passthrough/amd/iommu_map.c
b/xen/drivers/passthrough/amd/iommu_map.c
index 628aa60230..f876ce832b 100644
--- a/xen/drivers/passthrough/amd/iommu_map.c
+++ b/xen/drivers/passthrough/amd/iommu_map.c
@@ -758,6 +758,68 @@ void amd_iommu_share_p2m(struct domain *d)
}
}
+int __init amd_iommu_quarantine_init(struct domain *d)
+{
+ struct domain_iommu *hd = dom_iommu(d);
+ unsigned long max_gfn =
+ PFN_DOWN((1ul << DEFAULT_DOMAIN_ADDRESS_WIDTH) - 1);
+ unsigned int level = amd_iommu_get_paging_mode(max_gfn);
+ uint64_t *table;
+
+ if ( hd->arch.root_table )
+ {
+ ASSERT_UNREACHABLE();
+ return 0;
+ }
+
+ spin_lock(&hd->arch.mapping_lock);
+
+ hd->arch.root_table = alloc_amd_iommu_pgtable();
+ if ( !hd->arch.root_table )
+ goto out;
+
+ table = __map_domain_page(hd->arch.root_table);
+ while ( level )
+ {
+ struct page_info *pg;
+ unsigned int i;
+
+ /*
+ * The pgtable allocator is fine for the leaf page, as well as
+ * page table pages, and the resulting allocations are always
+ * zeroed.
+ */
+ pg = alloc_amd_iommu_pgtable();
+ if ( !pg )
+ break;
+
+ for ( i = 0; i < PTE_PER_TABLE_SIZE; i++ )
+ {
+ uint32_t *pde = (uint32_t *)&table[i];
+
+ /*
+ * PDEs are essentially a subset of PTEs, so this function
+ * is fine to use even at the leaf.
+ */
+ set_iommu_pde_present(pde, mfn_x(page_to_mfn(pg)), level - 1,
+ false, true);
+ }
+
+ unmap_domain_page(table);
+ table = __map_domain_page(pg);
+ level--;
+ }
+ unmap_domain_page(table);
+
+ out:
+ spin_unlock(&hd->arch.mapping_lock);
+
+ amd_iommu_flush_all_pages(d);
+
+ /* Pages leaked in failure case */
+ return level ? -ENOMEM : 0;
+}
+
/*
* Local variables:
* mode: C
diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c
b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index 15c13e1163..93ecae4a6c 100644
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -120,10 +120,6 @@ static void amd_iommu_setup_domain_device(
u8 bus = pdev->bus;
const struct domain_iommu *hd = dom_iommu(domain);
- /* dom_io is used as a sentinel for quarantined devices */
- if ( domain == dom_io )
- return;
-
BUG_ON( !hd->arch.root_table || !hd->arch.paging_mode ||
!iommu->dev_table.buffer );
@@ -226,7 +222,7 @@ static int __must_check allocate_domain_resources(struct
domain_iommu *hd)
return rc;
}
-static int get_paging_mode(unsigned long entries)
+int amd_iommu_get_paging_mode(unsigned long entries)
{
int level = 1;
@@ -248,7 +244,8 @@ static int amd_iommu_domain_init(struct domain *d)
/* For pv and dom0, stick with get_paging_mode(max_page)
* For HVM dom0, use 2 level page table at first */
- hd->arch.paging_mode = is_hvm_domain(d) ? 2 : get_paging_mode(max_page);
+ hd->arch.paging_mode = is_hvm_domain(d) ?
+ 2 : amd_iommu_get_paging_mode(max_page);
return 0;
}
@@ -281,10 +278,6 @@ void amd_iommu_disable_domain_device(struct domain *domain,
int req_id;
u8 bus = pdev->bus;
- /* dom_io is used as a sentinel for quarantined devices */
- if ( domain == dom_io )
- return;
-
BUG_ON ( iommu->dev_table.buffer == NULL );
req_id = get_dma_requestor_id(iommu->seg, PCI_BDF2(bus, devfn));
dte = iommu->dev_table.buffer + (req_id * IOMMU_DEV_TABLE_ENTRY_SIZE);
@@ -581,6 +574,7 @@ static void amd_dump_p2m_table(struct domain *d)
static const struct iommu_ops __initconstrel amd_iommu_ops = {
.init = amd_iommu_domain_init,
.hwdom_init = amd_iommu_hwdom_init,
+ .quarantine_init = amd_iommu_quarantine_init,
.add_device = amd_iommu_add_device,
.remove_device = amd_iommu_remove_device,
.assign_device = amd_iommu_assign_device,
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index 20db08e1df..a747bfb946 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -497,6 +497,21 @@ int iommu_iotlb_flush_all(struct domain *d, unsigned int
flush_flags)
return rc;
}
+static int __init iommu_quarantine_init(void)
+{
+ const struct domain_iommu *hd = dom_iommu(dom_io);
+ int rc;
+
+ rc = iommu_domain_init(dom_io);
+ if ( rc )
+ return rc;
+
+ if ( !hd->platform_ops->quarantine_init )
+ return 0;
+
+ return hd->platform_ops->quarantine_init(dom_io);
+}
+
int __init iommu_setup(void)
{
int rc = -ENODEV;
@@ -530,7 +545,7 @@ int __init iommu_setup(void)
printk("I/O virtualisation %sabled\n", iommu_enabled ? "en" : "dis");
if ( iommu_enabled )
{
- if ( iommu_domain_init(dom_io) )
+ if ( iommu_quarantine_init() )
panic("Could not set up quarantine\n");
printk(" - Dom0 mode: %s\n",
diff --git a/xen/drivers/passthrough/vtd/iommu.c
b/xen/drivers/passthrough/vtd/iommu.c
index 5663e9740d..576e72eba1 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -192,7 +192,7 @@ u64 alloc_pgtable_maddr(struct acpi_drhd_unit *drhd,
unsigned long npages)
nodeid_t node = NUMA_NO_NODE;
unsigned int i;
- rhsa = drhd_to_rhsa(drhd);
+ rhsa = drhd ? drhd_to_rhsa(drhd) : NULL;
if ( rhsa )
node = pxm_to_node(rhsa->proximity_domain);
@@ -1340,10 +1340,6 @@ int domain_context_mapping_one(
int agaw, rc, ret;
bool_t flush_dev_iotlb;
- /* dom_io is used as a sentinel for quarantined devices */
- if ( domain == dom_io )
- return 0;
-
ASSERT(pcidevs_locked());
spin_lock(&iommu->lock);
maddr = bus_to_context_maddr(iommu, bus);
@@ -1579,10 +1575,6 @@ int domain_context_unmap_one(
int iommu_domid, rc, ret;
bool_t flush_dev_iotlb;
- /* dom_io is used as a sentinel for quarantined devices */
- if ( domain == dom_io )
- return 0;
-
ASSERT(pcidevs_locked());
spin_lock(&iommu->lock);
@@ -1715,10 +1707,6 @@ static int domain_context_unmap(struct domain *domain,
u8 devfn,
goto out;
}
- /* dom_io is used as a sentinel for quarantined devices */
- if ( domain == dom_io )
- goto out;
-
/*
* if no other devices under the same iommu owned by this domain,
* clear iommu in iommu_bitmap and clear domain_id in domid_bitmp
@@ -2736,9 +2724,69 @@ static void vtd_dump_p2m_table(struct domain *d)
vtd_dump_p2m_table_level(hd->arch.pgd_maddr, agaw_to_level(hd->arch.agaw),
0, 0);
}
+static int __init intel_iommu_quarantine_init(struct domain *d)
+{
+ struct domain_iommu *hd = dom_iommu(d);
+ struct dma_pte *parent;
+ unsigned int agaw = width_to_agaw(DEFAULT_DOMAIN_ADDRESS_WIDTH);
+ unsigned int level = agaw_to_level(agaw);
+ int rc;
+
+ if ( hd->arch.pgd_maddr )
+ {
+ ASSERT_UNREACHABLE();
+ return 0;
+ }
+
+ spin_lock(&hd->arch.mapping_lock);
+
+ hd->arch.pgd_maddr = alloc_pgtable_maddr(NULL, 1);
+ if ( !hd->arch.pgd_maddr )
+ goto out;
+
+ parent = map_vtd_domain_page(hd->arch.pgd_maddr);
+ while ( level )
+ {
+ uint64_t maddr;
+ unsigned int offset;
+
+ /*
+ * The pgtable allocator is fine for the leaf page, as well as
+ * page table pages, and the resulting allocations are always
+ * zeroed.
+ */
+ maddr = alloc_pgtable_maddr(NULL, 1);
+ if ( !maddr )
+ break;
+
+ for ( offset = 0; offset < PTE_NUM; offset++ )
+ {
+ struct dma_pte *pte = &parent[offset];
+
+ dma_set_pte_addr(*pte, maddr);
+ dma_set_pte_readable(*pte);
+ }
+ iommu_flush_cache_page(parent, 1);
+
+ unmap_vtd_domain_page(parent);
+ parent = map_vtd_domain_page(maddr);
+ level--;
+ }
+ unmap_vtd_domain_page(parent);
+
+ out:
+ spin_unlock(&hd->arch.mapping_lock);
+
+ rc = iommu_flush_iotlb_all(d);
+
+ /* Pages leaked in failure case */
+ return level ? -ENOMEM : rc;
+}
+
const struct iommu_ops __initconstrel intel_iommu_ops = {
.init = intel_iommu_domain_init,
.hwdom_init = intel_iommu_hwdom_init,
+ .quarantine_init = intel_iommu_quarantine_init,
.add_device = intel_iommu_add_device,
.enable_device = intel_iommu_enable_device,
.remove_device = intel_iommu_remove_device,
diff --git a/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
b/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
index c5697565d6..5a160b89ca 100644
--- a/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
+++ b/xen/include/asm-x86/hvm/svm/amd-iommu-proto.h
@@ -51,6 +51,9 @@ void get_iommu_features(struct amd_iommu *iommu);
int amd_iommu_init(void);
int amd_iommu_update_ivrs_mapping_acpi(void);
+int amd_iommu_get_paging_mode(unsigned long entries);
+int amd_iommu_quarantine_init(struct domain *d);
+
/* mapping functions */
int __must_check amd_iommu_map_page(struct domain *d, dfn_t dfn,
mfn_t mfn, unsigned int flags,
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 70ee53d083..617c993f50 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -189,6 +189,7 @@ typedef int iommu_grdm_t(xen_pfn_t start, xen_ulong_t nr,
u32 id, void *ctxt);
struct iommu_ops {
int (*init)(struct domain *d);
void (*hwdom_init)(struct domain *d);
+ int (*quarantine_init)(struct domain *d);
int (*add_device)(u8 devfn, device_t *dev);
int (*enable_device)(device_t *dev);
int (*remove_device)(u8 devfn, device_t *dev);
--
generated by git-patchbot for /home/xen/git/xen.git#staging-4.12
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