IOMMU: Handle sibling device assignment correctly (re-send)

diff -r 28083093cc5d xen/arch/x86/domctl.c
@@ -526,6 +526,45 @@ long arch_do_domctl(
     }
     break;
 
+    case XEN_DOMCTL_get_device_group:
+    {
+        struct domain *d;
+        u32 max_sdevs;
+        u8 bus, devfn;
+        XEN_GUEST_HANDLE_64(uint32) sdevs;
+        int num_sdevs;
+
+        ret = -ENOSYS;
+        if ( !iommu_enabled )
+            break;
+
+        ret = -EINVAL;
+        if ( (d = rcu_lock_domain_by_id(domctl->domain)) == NULL )
+            break;
+
+        bus = (domctl->u.get_device_group.machine_bdf >> 16) & 0xff;
+        devfn = (domctl->u.get_device_group.machine_bdf >> 8) & 0xff;
+        max_sdevs = domctl->u.get_device_group.max_sdevs;
+        sdevs = domctl->u.get_device_group.sdev_array;
+
+        num_sdevs = iommu_get_device_group(d, bus, devfn, sdevs, max_sdevs);
+        if ( num_sdevs < 0 )
+        {
+            dprintk(XENLOG_ERR, "iommu_get_device_group() failed!\n");
+            ret = -EFAULT;
+            domctl->u.get_device_group.num_sdevs = 0;
+        }
+        else
+        {
+            ret = 0;
+            domctl->u.get_device_group.num_sdevs = num_sdevs;
+        }
+        if ( copy_to_guest(u_domctl, domctl, 1) )
+            ret = -EFAULT;
+        rcu_unlock_domain(d);
+    }
+    break;
+
     case XEN_DOMCTL_test_assign_device:
     {
         u8 bus, devfn;

diff -r 28083093cc5d xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -635,6 +635,16 @@ static void amd_iommu_return_device(
     reassign_device(s, t, bus, devfn);
 }
 
+static int amd_iommu_group_id(u8 bus, u8 devfn)
+{
+    int rt;
+    int bdf = (bus << 8) | devfn;
+    rt = ( bdf < ivrs_bdf_entries ) ?
+        ivrs_mappings[bdf].dte_requestor_id :
+        bdf;
+    return rt;
+}
+
 struct iommu_ops amd_iommu_ops = {
     .init = amd_iommu_domain_init,
     .assign_device  = amd_iommu_assign_device,

@@ -642,4 +652,5 @@ struct iommu_ops amd_iommu_ops = {
     .map_page = amd_iommu_map_page,
     .unmap_page = amd_iommu_unmap_page,
     .reassign_device = amd_iommu_return_device,
+    .get_device_group_id = amd_iommu_group_id,
 };

diff -r 28083093cc5d xen/drivers/passthrough/iommu.c
@@ -16,6 +16,7 @@
 #include <xen/sched.h>
 #include <xen/iommu.h>
 #include <xen/paging.h>
+#include <xen/guest_access.h>
 
 extern struct iommu_ops intel_iommu_ops;
 extern struct iommu_ops amd_iommu_ops;

@@ -216,7 +217,41 @@ static int iommu_setup(void)
 }
 __initcall(iommu_setup);
 
-
+int iommu_get_device_group(struct domain *d, u8 bus, u8 devfn, 
+    XEN_GUEST_HANDLE_64(uint32) buf, int max_sdevs)
+{
+    struct hvm_iommu *hd = domain_hvm_iommu(d);
+    struct pci_dev *pdev;
+    int group_id, sdev_id;
+    u32 bdf;
+    int i = 0;
+    struct iommu_ops *ops = hd->platform_ops;
+
+    if ( !iommu_enabled || !ops || !ops->get_device_group_id )
+        return 0;
+
+    group_id = ops->get_device_group_id(bus, devfn);
+
+    list_for_each_entry(pdev,
+        &(dom0->arch.hvm_domain.hvm_iommu.pdev_list), list)
+    {
+        if ( (pdev->bus == bus) && (pdev->devfn == devfn) )
+            continue;
+
+        sdev_id = ops->get_device_group_id(pdev->bus, pdev->devfn);
+        if ( (sdev_id == group_id) && (i < max_sdevs) )
+        {
+            bdf = 0;
+            bdf |= (pdev->bus & 0xff) << 16;
+            bdf |= (pdev->devfn & 0xff) << 8;
+            if ( unlikely(copy_to_guest_offset(buf, i, &bdf, 1)) )
+                return -1;
+            i++;
+        }
+    }
+
+    return i;
+}
 /*
  * Local variables:
  * mode: C

diff -r 28083093cc5d xen/drivers/passthrough/vtd/iommu.c
@@ -1946,6 +1946,7 @@ struct iommu_ops intel_iommu_ops = {
     .map_page = intel_iommu_map_page,
     .unmap_page = intel_iommu_unmap_page,
     .reassign_device = reassign_device_ownership,
+    .get_device_group_id = NULL,
 };
 
 /*

diff -r 28083093cc5d xen/include/public/domctl.h
@@ -448,6 +448,16 @@ typedef struct xen_domctl_assign_device 
 typedef struct xen_domctl_assign_device xen_domctl_assign_device_t;
 DEFINE_XEN_GUEST_HANDLE(xen_domctl_assign_device_t);
 
+/* Retrieve sibling devices infomation of machine_bdf */
+#define XEN_DOMCTL_get_device_group 50
+struct xen_domctl_get_device_group {
+    uint32_t  machine_bdf;      /* IN */
+    uint32_t  max_sdevs;        /* IN */
+    uint32_t  num_sdevs;        /* OUT */
+    XEN_GUEST_HANDLE_64(uint32)  sdev_array;   /* OUT */
+};
+typedef struct xen_domctl_get_device_group xen_domctl_get_device_group_t;
+DEFINE_XEN_GUEST_HANDLE(xen_domctl_get_device_group_t);
 
 /* Pass-through interrupts: bind real irq -> hvm devfn. */
 #define XEN_DOMCTL_bind_pt_irq       38

@@ -619,6 +629,7 @@ struct xen_domctl {
         struct xen_domctl_hvmcontext        hvmcontext;
         struct xen_domctl_address_size      address_size;
         struct xen_domctl_sendtrigger       sendtrigger;
+        struct xen_domctl_get_device_group  get_device_group;
         struct xen_domctl_assign_device     assign_device;
         struct xen_domctl_bind_pt_irq       bind_pt_irq;
         struct xen_domctl_memory_mapping    memory_mapping;

diff -r 28083093cc5d xen/include/xen/iommu.h
@@ -59,6 +59,8 @@ int device_assigned(u8 bus, u8 devfn);
 int device_assigned(u8 bus, u8 devfn);
 int assign_device(struct domain *d, u8 bus, u8 devfn);
 void deassign_device(struct domain *d, u8 bus, u8 devfn);
+int iommu_get_device_group(struct domain *d, u8 bus, u8 devfn, 
+    XEN_GUEST_HANDLE_64(uint32) buf, int max_sdevs);
 void reassign_device_ownership(struct domain *source,
                                struct domain *target,
                                u8 bus, u8 devfn);

@@ -95,6 +97,7 @@ struct iommu_ops {
     int (*unmap_page)(struct domain *d, unsigned long gfn);
     void (*reassign_device)(struct domain *s, struct domain *t,
                             u8 bus, u8 devfn);
+    int (*get_device_group_id)(u8 bus, u8 devfn);
 };
 
 #endif /* _IOMMU_H_ */