IOMMU: add phantom function support

Apart from generating device context entries for the base function,
all phantom functions also need context entries to be generated for
them.

In order to distinguish different use cases, a variant of
pci_get_pdev() is being introduced that, even when passed a phantom
function number, would return the underlying actual device.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: "Zhang, Xiantao" <xiantao.zhang@intel.com>

7 files changed, 167 insertions, 19 deletions

diff --git a/xen/drivers/passthrough/amd/iommu_cmd.c b/xen/drivers/passthrough/amd/iommu_cmd.c
index fff6495639..4c6014950b 100644
--- a/xen/drivers/passthrough/amd/iommu_cmd.c
+++ b/xen/drivers/passthrough/amd/iommu_cmd.c
@@ -339,7 +339,15 @@ static void amd_iommu_flush_all_iotlbs(struct domain *d, uint64_t gaddr,
         return;
 
     for_each_pdev( d, pdev )
-        amd_iommu_flush_iotlb(pdev->devfn, pdev, gaddr, order);
+    {
+        u8 devfn = pdev->devfn;
+
+        do {
+            amd_iommu_flush_iotlb(devfn, pdev, gaddr, order);
+            devfn += pdev->phantom_stride;
+        } while ( devfn != pdev->devfn &&
+                  PCI_SLOT(devfn) == PCI_SLOT(pdev->devfn) );
+    }
 }
 
 /* Flush iommu cache after p2m changes. */
diff --git a/xen/drivers/passthrough/amd/iommu_init.c b/xen/drivers/passthrough/amd/iommu_init.c
index 1cbdda344a..cdfdd2e832 100644
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -667,7 +667,7 @@ void parse_ppr_log_entry(struct amd_iommu *iommu, u32 entry[])
     devfn = PCI_DEVFN2(device_id);
 
     spin_lock(&pcidevs_lock);
-    pdev = pci_get_pdev(iommu->seg, bus, devfn);
+    pdev = pci_get_real_pdev(iommu->seg, bus, devfn);
     spin_unlock(&pcidevs_lock);
 
     if ( pdev )
diff --git a/xen/drivers/passthrough/amd/iommu_map.c b/xen/drivers/passthrough/amd/iommu_map.c
index 46a7421b7e..1294561114 100644
--- a/xen/drivers/passthrough/amd/iommu_map.c
+++ b/xen/drivers/passthrough/amd/iommu_map.c
@@ -598,7 +598,6 @@ static int update_paging_mode(struct domain *d, unsigned long gfn)
         for_each_pdev( d, pdev )
         {
             bdf = PCI_BDF2(pdev->bus, pdev->devfn);
-            req_id = get_dma_requestor_id(pdev->seg, bdf);
             iommu = find_iommu_for_device(pdev->seg, bdf);
             if ( !iommu )
             {
@@ -607,16 +606,21 @@ static int update_paging_mode(struct domain *d, unsigned long gfn)
             }
 
             spin_lock_irqsave(&iommu->lock, flags);
-            device_entry = iommu->dev_table.buffer +
-                           (req_id * IOMMU_DEV_TABLE_ENTRY_SIZE);
-
-            /* valid = 0 only works for dom0 passthrough mode */
-            amd_iommu_set_root_page_table((u32 *)device_entry,
-                                          page_to_maddr(hd->root_table),
-                                          hd->domain_id,
-                                          hd->paging_mode, 1);
-
-            amd_iommu_flush_device(iommu, req_id);
+            do {
+                req_id = get_dma_requestor_id(pdev->seg, bdf);
+                device_entry = iommu->dev_table.buffer +
+                               (req_id * IOMMU_DEV_TABLE_ENTRY_SIZE);
+
+                /* valid = 0 only works for dom0 passthrough mode */
+                amd_iommu_set_root_page_table((u32 *)device_entry,
+                                              page_to_maddr(hd->root_table),
+                                              hd->domain_id,
+                                              hd->paging_mode, 1);
+
+                amd_iommu_flush_device(iommu, req_id);
+                bdf += pdev->phantom_stride;
+            } while ( PCI_DEVFN2(bdf) != pdev->devfn &&
+                      PCI_SLOT(bdf) == PCI_SLOT(pdev->devfn) );
             spin_unlock_irqrestore(&iommu->lock, flags);
         }
 
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index b1c62b7ea2..19e784b908 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -158,6 +158,8 @@ void __init iommu_dom0_init(struct domain *d)
 int iommu_add_device(struct pci_dev *pdev)
 {
     struct hvm_iommu *hd;
+    int rc;
+    u8 devfn;
 
     if ( !pdev->domain )
         return -EINVAL;
@@ -168,7 +170,20 @@ int iommu_add_device(struct pci_dev *pdev)
     if ( !iommu_enabled || !hd->platform_ops )
         return 0;
 
-    return hd->platform_ops->add_device(pdev->devfn, pdev);
+    rc = hd->platform_ops->add_device(pdev->devfn, pdev);
+    if ( rc || !pdev->phantom_stride )
+        return rc;
+
+    for ( devfn = pdev->devfn ; ; )
+    {
+        devfn += pdev->phantom_stride;
+        if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
+            return 0;
+        rc = hd->platform_ops->add_device(devfn, pdev);
+        if ( rc )
+            printk(XENLOG_WARNING "IOMMU: add %04x:%02x:%02x.%u failed (%d)\n",
+                   pdev->seg, pdev->bus, PCI_SLOT(devfn), PCI_FUNC(devfn), rc);
+    }
 }
 
 int iommu_enable_device(struct pci_dev *pdev)
@@ -191,6 +206,8 @@ int iommu_enable_device(struct pci_dev *pdev)
 int iommu_remove_device(struct pci_dev *pdev)
 {
     struct hvm_iommu *hd;
+    u8 devfn;
+
     if ( !pdev->domain )
         return -EINVAL;
 
@@ -198,6 +215,22 @@ int iommu_remove_device(struct pci_dev *pdev)
     if ( !iommu_enabled || !hd->platform_ops )
         return 0;
 
+    for ( devfn = pdev->devfn ; pdev->phantom_stride; )
+    {
+        int rc;
+
+        devfn += pdev->phantom_stride;
+        if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
+            break;
+        rc = hd->platform_ops->remove_device(devfn, pdev);
+        if ( !rc )
+            continue;
+
+        printk(XENLOG_ERR "IOMMU: remove %04x:%02x:%02x.%u failed (%d)\n",
+               pdev->seg, pdev->bus, PCI_SLOT(devfn), PCI_FUNC(devfn), rc);
+        return rc;
+    }
+
     return hd->platform_ops->remove_device(pdev->devfn, pdev);
 }
 
@@ -245,6 +278,18 @@ static int assign_device(struct domain *d, u16 seg, u8 bus, u8 devfn)
     if ( (rc = hd->platform_ops->assign_device(d, devfn, pdev)) )
         goto done;
 
+    for ( ; pdev->phantom_stride; rc = 0 )
+    {
+        devfn += pdev->phantom_stride;
+        if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
+            break;
+        rc = hd->platform_ops->assign_device(d, devfn, pdev);
+        if ( rc )
+            printk(XENLOG_G_WARNING "d%d: assign %04x:%02x:%02x.%u failed (%d)\n",
+                   d->domain_id, seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
+                   rc);
+    }
+
     if ( has_arch_pdevs(d) && !need_iommu(d) )
     {
         d->need_iommu = 1;
@@ -377,6 +422,21 @@ int deassign_device(struct domain *d, u16 seg, u8 bus, u8 devfn)
     if ( !pdev )
         return -ENODEV;
 
+    while ( pdev->phantom_stride )
+    {
+        devfn += pdev->phantom_stride;
+        if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
+            break;
+        ret = hd->platform_ops->reassign_device(d, dom0, devfn, pdev);
+        if ( !ret )
+            continue;
+
+        printk(XENLOG_G_ERR "d%d: deassign %04x:%02x:%02x.%u failed (%d)\n",
+               d->domain_id, seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn), ret);
+        return ret;
+    }
+
+    devfn = pdev->devfn;
     ret = hd->platform_ops->reassign_device(d, dom0, devfn, pdev);
     if ( ret )
     {
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index 3aed291abe..cd708f3427 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -144,6 +144,8 @@ static struct pci_dev *alloc_pdev(struct pci_seg *pseg, u8 bus, u8 devfn)
     /* update bus2bridge */
     switch ( pdev->type = pdev_type(pseg->nr, bus, devfn) )
     {
+        int pos;
+        u16 cap;
         u8 sec_bus, sub_bus;
 
         case DEV_TYPE_PCIe_BRIDGE:
@@ -167,6 +169,20 @@ static struct pci_dev *alloc_pdev(struct pci_seg *pseg, u8 bus, u8 devfn)
             break;
 
         case DEV_TYPE_PCIe_ENDPOINT:
+            pos = pci_find_cap_offset(pseg->nr, bus, PCI_SLOT(devfn),
+                                      PCI_FUNC(devfn), PCI_CAP_ID_EXP);
+            BUG_ON(!pos);
+            cap = pci_conf_read16(pseg->nr, bus, PCI_SLOT(devfn),
+                                  PCI_FUNC(devfn), pos + PCI_EXP_DEVCAP);
+            if ( cap & PCI_EXP_DEVCAP_PHANTOM )
+            {
+                pdev->phantom_stride = 8 >> MASK_EXTR(cap,
+                                                      PCI_EXP_DEVCAP_PHANTOM);
+                if ( PCI_FUNC(devfn) >= pdev->phantom_stride )
+                    pdev->phantom_stride = 0;
+            }
+            break;
+
         case DEV_TYPE_PCI:
             break;
 
@@ -290,6 +306,27 @@ struct pci_dev *pci_get_pdev(int seg, int bus, int devfn)
     return NULL;
 }
 
+struct pci_dev *pci_get_real_pdev(int seg, int bus, int devfn)
+{
+    struct pci_dev *pdev;
+    int stride;
+
+    if ( seg < 0 || bus < 0 || devfn < 0 )
+        return NULL;
+
+    for ( pdev = pci_get_pdev(seg, bus, devfn), stride = 4;
+          !pdev && stride; stride >>= 1 )
+    {
+        if ( !(devfn & (8 - stride)) )
+            continue;
+        pdev = pci_get_pdev(seg, bus, devfn & ~(8 - stride));
+        if ( pdev && stride != pdev->phantom_stride )
+            pdev = NULL;
+    }
+
+    return pdev;
+}
+
 struct pci_dev *pci_get_pdev_by_domain(
     struct domain *d, int seg, int bus, int devfn)
 {
@@ -488,8 +525,19 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn, const struct pci_dev_info *info)
 
 out:
     spin_unlock(&pcidevs_lock);
-    printk(XENLOG_DEBUG "PCI add %s %04x:%02x:%02x.%u\n", pdev_type,
-           seg, bus, slot, func);
+    if ( !ret )
+    {
+        printk(XENLOG_DEBUG "PCI add %s %04x:%02x:%02x.%u\n", pdev_type,
+               seg, bus, slot, func);
+        while ( pdev->phantom_stride )
+        {
+            func += pdev->phantom_stride;
+            if ( PCI_SLOT(func) )
+                break;
+            printk(XENLOG_DEBUG "PCI phantom %04x:%02x:%02x.%u\n",
+                   seg, bus, slot, func);
+        }
+    }
     return ret;
 }
 
@@ -681,7 +729,7 @@ void pci_check_disable_device(u16 seg, u8 bus, u8 devfn)
     u16 cword;
 
     spin_lock(&pcidevs_lock);
-    pdev = pci_get_pdev(seg, bus, devfn);
+    pdev = pci_get_real_pdev(seg, bus, devfn);
     if ( pdev )
     {
         if ( now < pdev->fault.time ||
@@ -698,6 +746,7 @@ void pci_check_disable_device(u16 seg, u8 bus, u8 devfn)
 
     /* Tell the device to stop DMAing; we can't rely on the guest to
      * control it for us. */
+    devfn = pdev->devfn;
     cword = pci_conf_read16(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
                             PCI_COMMAND);
     pci_conf_write16(seg, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
@@ -759,6 +808,27 @@ struct setup_dom0 {
     int (*handler)(u8 devfn, struct pci_dev *);
 };
 
+static void setup_one_dom0_device(const struct setup_dom0 *ctxt,
+                                  struct pci_dev *pdev)
+{
+    u8 devfn = pdev->devfn;
+
+    do {
+        int err = ctxt->handler(devfn, pdev);
+
+        if ( err )
+        {
+            printk(XENLOG_ERR "setup %04x:%02x:%02x.%u for d%d failed (%d)\n",
+                   pdev->seg, pdev->bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
+                   ctxt->d->domain_id, err);
+            if ( devfn == pdev->devfn )
+                return;
+        }
+        devfn += pdev->phantom_stride;
+    } while ( devfn != pdev->devfn &&
+              PCI_SLOT(devfn) == PCI_SLOT(pdev->devfn) );
+}
+
 static int __init _setup_dom0_pci_devices(struct pci_seg *pseg, void *arg)
 {
     struct setup_dom0 *ctxt = arg;
@@ -777,12 +847,12 @@ static int __init _setup_dom0_pci_devices(struct pci_seg *pseg, void *arg)
             {
                 pdev->domain = ctxt->d;
                 list_add(&pdev->domain_list, &ctxt->d->arch.pdev_list);
-                ctxt->handler(devfn, pdev);
+                setup_one_dom0_device(ctxt, pdev);
             }
             else if ( pdev->domain == dom_xen )
             {
                 pdev->domain = ctxt->d;
-                ctxt->handler(devfn, pdev);
+                setup_one_dom0_device(ctxt, pdev);
                 pdev->domain = dom_xen;
             }
             else if ( pdev->domain != ctxt->d )
diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index 1919ed7d93..f7074cf2ff 100644
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -58,6 +58,9 @@ do {                                                            \
 
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]) + __must_be_array(x))
 
+#define MASK_EXTR(v, m) (((v) & (m)) / ((m) & -(m)))
+#define MASK_INSR(v, m) (((v) * ((m) & -(m))) & (m))
+
 #define reserve_bootmem(_p,_l) ((void)0)
 
 struct domain;
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index 7b550a3508..9724bb29c8 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -63,6 +63,8 @@ struct pci_dev {
     const u8 bus;
     const u8 devfn;
 
+    u8 phantom_stride;
+
     enum pdev_type {
         DEV_TYPE_PCI_UNKNOWN,
         DEV_TYPE_PCIe_ENDPOINT,
@@ -114,6 +116,7 @@ int pci_ro_device(int seg, int bus, int devfn);
 void arch_pci_ro_device(int seg, int bdf);
 int pci_hide_device(int bus, int devfn);
 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(
     struct domain *, int seg, int bus, int devfn);
 void pci_check_disable_device(u16 seg, u8 bus, u8 devfn);