[PATCH v12 6/6] vt-d: fix vt-d Device-TLB flush timeout issue

["Xu, Quan" <quan.xu@intel.com>]

From: Quan Xu <quan.xu@intel.com>

If Device-TLB flush timed out, we hide the target ATS device
immediately and crash the domain owning this ATS device. If
impacted domain is hardware domain, just throw out a warning.

By hiding the device, we make sure it can't be assigned to any
domain any longer (see device_assigned).

Signed-off-by: Quan Xu <quan.xu@intel.com>

CC: Jan Beulich <jbeulich@suse.com>
CC: Kevin Tian <kevin.tian@intel.com>
CC: Feng Wu <feng.wu@intel.com>

---
v12:
   1. a forward declaration struct pci_ats_dev*, instead of
      including ats.h.
   2. eliminate the loop.
   3. use the same logic for logging and crashing as I did in
      other series (despite I have moved the domain crash logic
      up to the generic IOMMU layer, I think I am better still
      leave it as is).
   4. enhance dev_invalidate_sync() with ASSERT().
---
 xen/drivers/passthrough/pci.c         |  6 +--
 xen/drivers/passthrough/vtd/extern.h  |  5 ++-
 xen/drivers/passthrough/vtd/qinval.c  | 75 +++++++++++++++++++++++++++++------
 xen/drivers/passthrough/vtd/x86/ats.c |  9 +----
 xen/include/xen/pci.h                 |  1 +
 5 files changed, 71 insertions(+), 25 deletions(-)

diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index 98936f55c..843dc88 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -419,7 +419,7 @@ static void free_pdev(struct pci_seg *pseg, struct pci_dev *pdev)
     xfree(pdev);
 }
 
-static void _pci_hide_device(struct pci_dev *pdev)
+void pci_hide_existing_device(struct pci_dev *pdev)
 {
     if ( pdev->domain )
         return;
@@ -436,7 +436,7 @@ int __init pci_hide_device(int bus, int devfn)
     pdev = alloc_pdev(get_pseg(0), bus, devfn);
     if ( pdev )
     {
-        _pci_hide_device(pdev);
+        pci_hide_existing_device(pdev);
         rc = 0;
     }
     pcidevs_unlock();
@@ -466,7 +466,7 @@ int __init pci_ro_device(int seg, int bus, int devfn)
     }
 
     __set_bit(PCI_BDF2(bus, devfn), pseg->ro_map);
-    _pci_hide_device(pdev);
+    pci_hide_existing_device(pdev);
 
     return 0;
 }
diff --git a/xen/drivers/passthrough/vtd/extern.h b/xen/drivers/passthrough/vtd/extern.h
index 45357f2..efaff28 100644
--- a/xen/drivers/passthrough/vtd/extern.h
+++ b/xen/drivers/passthrough/vtd/extern.h
@@ -25,6 +25,7 @@
 
 #define VTDPREFIX "[VT-D]"
 
+struct pci_ats_dev;
 extern bool_t rwbf_quirk;
 
 void print_iommu_regs(struct acpi_drhd_unit *drhd);
@@ -60,8 +61,8 @@ int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
                          u64 addr, unsigned int size_order, u64 type);
 
 int __must_check qinval_device_iotlb_sync(struct iommu *iommu,
-                                          u32 max_invs_pend,
-                                          u16 sid, u16 size, u64 addr);
+                                          struct pci_ats_dev *ats_dev,
+                                          u16 did, u16 size, u64 addr);
 
 unsigned int get_cache_line_size(void);
 void cacheline_flush(char *);
diff --git a/xen/drivers/passthrough/vtd/qinval.c b/xen/drivers/passthrough/vtd/qinval.c
index 4492b29..e4e2771 100644
--- a/xen/drivers/passthrough/vtd/qinval.c
+++ b/xen/drivers/passthrough/vtd/qinval.c
@@ -27,11 +27,11 @@
 #include "dmar.h"
 #include "vtd.h"
 #include "extern.h"
+#include "../ats.h"
 
 #define VTD_QI_TIMEOUT	1
 
-static int __must_check invalidate_sync(struct iommu *iommu,
-                                        bool_t flush_dev_iotlb);
+static int __must_check invalidate_sync(struct iommu *iommu);
 
 static void print_qi_regs(struct iommu *iommu)
 {
@@ -103,7 +103,7 @@ static int __must_check queue_invalidate_context_sync(struct iommu *iommu,
 
     unmap_vtd_domain_page(qinval_entries);
 
-    return invalidate_sync(iommu, 0);
+    return invalidate_sync(iommu);
 }
 
 static int __must_check queue_invalidate_iotlb_sync(struct iommu *iommu,
@@ -140,7 +140,7 @@ static int __must_check queue_invalidate_iotlb_sync(struct iommu *iommu,
     qinval_update_qtail(iommu, index);
     spin_unlock_irqrestore(&iommu->register_lock, flags);
 
-    return invalidate_sync(iommu, 0);
+    return invalidate_sync(iommu);
 }
 
 static int __must_check queue_invalidate_wait(struct iommu *iommu,
@@ -199,24 +199,73 @@ static int __must_check queue_invalidate_wait(struct iommu *iommu,
     return -EOPNOTSUPP;
 }
 
-static int __must_check invalidate_sync(struct iommu *iommu,
-                                        bool_t flush_dev_iotlb)
+static int __must_check invalidate_sync(struct iommu *iommu)
 {
     struct qi_ctrl *qi_ctrl = iommu_qi_ctrl(iommu);
 
     ASSERT(qi_ctrl->qinval_maddr);
 
-    return queue_invalidate_wait(iommu, 0, 1, 1, flush_dev_iotlb);
+    return queue_invalidate_wait(iommu, 0, 1, 1, 0);
+}
+
+static void dev_invalidate_iotlb_timeout(struct iommu *iommu, u16 did,
+                                         struct pci_dev *pdev)
+{
+    struct domain *d = NULL;
+
+    if ( test_bit(did, iommu->domid_bitmap) )
+        d = rcu_lock_domain_by_id(iommu->domid_map[did]);
+
+    /*
+     * In case the domain has been freed or the IOMMU domid bitmap is
+     * not valid, the device no longer belongs to this domain.
+     */
+    if ( d == NULL )
+        return;
+
+    pcidevs_lock();
+    ASSERT(pdev->domain);
+    list_del(&pdev->domain_list);
+    pdev->domain = NULL;
+    pci_hide_existing_device(pdev);
+    pcidevs_unlock();
+
+    if ( !d->is_shutting_down && printk_ratelimit() )
+        printk(XENLOG_WARNING VTDPREFIX
+               " dom%d: ATS device %04x:%02x:%02x.%u flush failed\n",
+               d->domain_id, pdev->seg, pdev->bus,
+               PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
+
+    if ( !is_hardware_domain(d) )
+        domain_crash(d);
+
+    rcu_unlock_domain(d);
+}
+
+static int __must_check dev_invalidate_sync(struct iommu *iommu, u16 did,
+                                            struct pci_dev *pdev)
+{
+    struct qi_ctrl *qi_ctrl = iommu_qi_ctrl(iommu);
+    int rc;
+
+    ASSERT(qi_ctrl->qinval_maddr);
+    rc = queue_invalidate_wait(iommu, 0, 1, 1, 1);
+
+    if ( rc == -ETIMEDOUT )
+        dev_invalidate_iotlb_timeout(iommu, did, pdev);
+
+    return rc;
 }
 
 int qinval_device_iotlb_sync(struct iommu *iommu,
-                             u32 max_invs_pend,
-                             u16 sid, u16 size, u64 addr)
+                             struct pci_ats_dev *ats_dev,
+                             u16 did, u16 size, u64 addr)
 {
     unsigned long flags;
     unsigned int index;
     u64 entry_base;
     struct qinval_entry *qinval_entry, *qinval_entries;
+    struct pci_dev *pdev = ats_dev->pci_dev;
 
     spin_lock_irqsave(&iommu->register_lock, flags);
     index = qinval_next_index(iommu);
@@ -227,9 +276,9 @@ int qinval_device_iotlb_sync(struct iommu *iommu,
 
     qinval_entry->q.dev_iotlb_inv_dsc.lo.type = TYPE_INVAL_DEVICE_IOTLB;
     qinval_entry->q.dev_iotlb_inv_dsc.lo.res_1 = 0;
-    qinval_entry->q.dev_iotlb_inv_dsc.lo.max_invs_pend = max_invs_pend;
+    qinval_entry->q.dev_iotlb_inv_dsc.lo.max_invs_pend = ats_dev->ats_queue_depth;
     qinval_entry->q.dev_iotlb_inv_dsc.lo.res_2 = 0;
-    qinval_entry->q.dev_iotlb_inv_dsc.lo.sid = sid;
+    qinval_entry->q.dev_iotlb_inv_dsc.lo.sid = PCI_BDF2(pdev->bus, pdev->devfn);
     qinval_entry->q.dev_iotlb_inv_dsc.lo.res_3 = 0;
 
     qinval_entry->q.dev_iotlb_inv_dsc.hi.size = size;
@@ -240,7 +289,7 @@ int qinval_device_iotlb_sync(struct iommu *iommu,
     qinval_update_qtail(iommu, index);
     spin_unlock_irqrestore(&iommu->register_lock, flags);
 
-    return invalidate_sync(iommu, 1);
+    return dev_invalidate_sync(iommu, did, pdev);
 }
 
 static int __must_check queue_invalidate_iec_sync(struct iommu *iommu,
@@ -271,7 +320,7 @@ static int __must_check queue_invalidate_iec_sync(struct iommu *iommu,
     qinval_update_qtail(iommu, index);
     spin_unlock_irqrestore(&iommu->register_lock, flags);
 
-    ret = invalidate_sync(iommu, 0);
+    ret = invalidate_sync(iommu);
 
     /*
      * reading vt-d architecture register will ensure
diff --git a/xen/drivers/passthrough/vtd/x86/ats.c b/xen/drivers/passthrough/vtd/x86/ats.c
index a6c53ea..be2a155 100644
--- a/xen/drivers/passthrough/vtd/x86/ats.c
+++ b/xen/drivers/passthrough/vtd/x86/ats.c
@@ -121,15 +121,12 @@ int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
     list_for_each_entry( pdev, &ats_devices, list )
     {
         struct pci_dev *pci_dev = pdev->pci_dev;
-        u16 sid;
         bool_t sbit;
         int rc = 0;
 
         if ( !pci_dev )
             continue;
 
-        sid = PCI_BDF2(pci_dev->bus, pci_dev->devfn);
-
         /* Only invalidate devices that belong to this IOMMU */
         if ( pdev->iommu != iommu )
             continue;
@@ -144,8 +141,7 @@ int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
             /* invalidate all translations: sbit=1,bit_63=0,bit[62:12]=1 */
             sbit = 1;
             addr = (~0UL << PAGE_SHIFT_4K) & 0x7FFFFFFFFFFFFFFF;
-            rc = qinval_device_iotlb_sync(iommu, pdev->ats_queue_depth,
-                                          sid, sbit, addr);
+            rc = qinval_device_iotlb_sync(iommu, pdev, did, sbit, addr);
             break;
         case DMA_TLB_PSI_FLUSH:
             if ( !device_in_domain(iommu, pdev, did) )
@@ -164,8 +160,7 @@ int dev_invalidate_iotlb(struct iommu *iommu, u16 did,
                 addr |= (((u64)1 << (size_order - 1)) - 1) << PAGE_SHIFT_4K;
             }
 
-            rc = qinval_device_iotlb_sync(iommu, pdev->ats_queue_depth,
-                                          sid, sbit, addr);
+            rc = qinval_device_iotlb_sync(iommu, pdev, did, sbit, addr);
             break;
         default:
             dprintk(XENLOG_WARNING VTDPREFIX, "invalid vt-d flush type\n");
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index 6ed29dd..e4940cd 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -118,6 +118,7 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
 int pci_remove_device(u16 seg, u8 bus, u8 devfn);
 int pci_ro_device(int seg, int bus, int devfn);
 int pci_hide_device(int bus, int devfn);
+void pci_hide_existing_device(struct pci_dev *pdev);
 struct pci_dev *pci_get_pdev(int seg, int bus, int devfn);
 struct pci_dev *pci_get_real_pdev(int seg, int bus, int devfn);
 struct pci_dev *pci_get_pdev_by_domain(
-- 
1.9.1


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