[RFC][PATCH 07/13] xen/passthrough: extend hypercall to support rdm reservation policy

[Tiejun Chen <tiejun.chen@intel.com>]

This patch extends the existing hypercall to support rdm reservation policy.
We return error or just throw out a warning message depending on whether
the policy is 'force' or 'try'.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
 xen/drivers/passthrough/amd/pci_amd_iommu.c |  3 ++-
 xen/drivers/passthrough/pci.c               | 10 +++++----
 xen/drivers/passthrough/vtd/iommu.c         | 32 +++++++++++++++++++++--------
 xen/include/public/domctl.h                 |  4 ++++
 xen/include/xen/iommu.h                     |  2 +-
 5 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index e83bb35..920b35a 100644
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -394,7 +394,8 @@ static int reassign_device(struct domain *source, struct domain *target,
 }
 
 static int amd_iommu_assign_device(struct domain *d, u8 devfn,
-                                   struct pci_dev *pdev)
+                                   struct pci_dev *pdev,
+                                   u32 flag)
 {
     struct ivrs_mappings *ivrs_mappings = get_ivrs_mappings(pdev->seg);
     int bdf = PCI_BDF2(pdev->bus, devfn);
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index 4b83583..1b040d9 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -1333,7 +1333,7 @@ static int device_assigned(u16 seg, u8 bus, u8 devfn)
     return pdev ? 0 : -EBUSY;
 }
 
-static int assign_device(struct domain *d, u16 seg, u8 bus, u8 devfn)
+static int assign_device(struct domain *d, u16 seg, u8 bus, u8 devfn, u32 flag)
 {
     struct hvm_iommu *hd = domain_hvm_iommu(d);
     struct pci_dev *pdev;
@@ -1383,7 +1383,7 @@ static int assign_device(struct domain *d, u16 seg, u8 bus, u8 devfn)
 
     pdev->fault.count = 0;
 
-    if ( (rc = hd->platform_ops->assign_device(d, devfn, pci_to_dev(pdev))) )
+    if ( (rc = hd->platform_ops->assign_device(d, devfn, pci_to_dev(pdev), flag)) )
         goto done;
 
     for ( ; pdev->phantom_stride; rc = 0 )
@@ -1391,7 +1391,7 @@ static int assign_device(struct domain *d, u16 seg, u8 bus, u8 devfn)
         devfn += pdev->phantom_stride;
         if ( PCI_SLOT(devfn) != PCI_SLOT(pdev->devfn) )
             break;
-        rc = hd->platform_ops->assign_device(d, devfn, pci_to_dev(pdev));
+        rc = hd->platform_ops->assign_device(d, devfn, pci_to_dev(pdev), flag);
         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),
@@ -1508,6 +1508,7 @@ int iommu_do_pci_domctl(
 {
     u16 seg;
     u8 bus, devfn;
+    u32 flag;
     int ret = 0;
 
     switch ( domctl->cmd )
@@ -1576,9 +1577,10 @@ int iommu_do_pci_domctl(
         seg = domctl->u.assign_device.machine_sbdf >> 16;
         bus = (domctl->u.assign_device.machine_sbdf >> 8) & 0xff;
         devfn = domctl->u.assign_device.machine_sbdf & 0xff;
+        flag = domctl->u.assign_device.sbdf_flag;
 
         ret = device_assigned(seg, bus, devfn) ?:
-              assign_device(d, seg, bus, devfn);
+              assign_device(d, seg, bus, devfn, flag);
         if ( ret == -ERESTART )
             ret = hypercall_create_continuation(__HYPERVISOR_domctl,
                                                 "h", u_domctl);
diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index f8fc6c3..2681166 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1793,8 +1793,14 @@ static void iommu_set_pgd(struct domain *d)
     hd->arch.pgd_maddr = pagetable_get_paddr(pagetable_from_mfn(pgd_mfn));
 }
 
+/*
+ * In some cases, e.g. add a device to hwdomain, and remove a device from
+ * user domain, 'try' is fine enough since this is always safe to hwdomain.
+ */
+#define XEN_DOMCTL_PCIDEV_RDM_DEFAULT XEN_DOMCTL_PCIDEV_RDM_TRY
 static int rmrr_identity_mapping(struct domain *d, bool_t map,
-                                 const struct acpi_rmrr_unit *rmrr)
+                                 const struct acpi_rmrr_unit *rmrr,
+                                 u32 flag)
 {
     unsigned long base_pfn = rmrr->base_address >> PAGE_SHIFT_4K;
     unsigned long end_pfn = PAGE_ALIGN_4K(rmrr->end_address) >> PAGE_SHIFT_4K;
@@ -1851,7 +1857,14 @@ static int rmrr_identity_mapping(struct domain *d, bool_t map,
         if ( !is_hardware_domain(d) )
         {
             if ( (err = set_identity_p2m_entry(d, base_pfn, p2m_access_rw)) )
-                return err;
+            {
+                if ( flag == XEN_DOMCTL_PCIDEV_RDM_TRY )
+                {
+                    printk(XENLOG_G_WARNING "Some devices may work failed .\n");
+                }
+                else
+                    return err;
+            }
         }
         base_pfn++;
     }
@@ -1892,7 +1905,8 @@ static int intel_iommu_add_device(u8 devfn, struct pci_dev *pdev)
              PCI_BUS(bdf) == pdev->bus &&
              PCI_DEVFN2(bdf) == devfn )
         {
-            ret = rmrr_identity_mapping(pdev->domain, 1, rmrr);
+            ret = rmrr_identity_mapping(pdev->domain, 1, rmrr,
+                                        XEN_DOMCTL_PCIDEV_RDM_DEFAULT);
             if ( ret )
                 dprintk(XENLOG_ERR VTDPREFIX, "d%d: RMRR mapping failed\n",
                         pdev->domain->domain_id);
@@ -1933,7 +1947,8 @@ static int intel_iommu_remove_device(u8 devfn, struct pci_dev *pdev)
              PCI_DEVFN2(bdf) != devfn )
             continue;
 
-        rmrr_identity_mapping(pdev->domain, 0, rmrr);
+        rmrr_identity_mapping(pdev->domain, 0, rmrr,
+                              XEN_DOMCTL_PCIDEV_RDM_DEFAULT);
     }
 
     return domain_context_unmap(pdev->domain, devfn, pdev);
@@ -2091,7 +2106,7 @@ static void __hwdom_init setup_hwdom_rmrr(struct domain *d)
     spin_lock(&pcidevs_lock);
     for_each_rmrr_device ( rmrr, bdf, i )
     {
-        ret = rmrr_identity_mapping(d, 1, rmrr);
+        ret = rmrr_identity_mapping(d, 1, rmrr, XEN_DOMCTL_PCIDEV_RDM_DEFAULT);
         if ( ret )
             dprintk(XENLOG_ERR VTDPREFIX,
                      "IOMMU: mapping reserved region failed\n");
@@ -2234,7 +2249,8 @@ static int reassign_device_ownership(
                  PCI_BUS(bdf) == pdev->bus &&
                  PCI_DEVFN2(bdf) == devfn )
             {
-                ret = rmrr_identity_mapping(source, 0, rmrr);
+                ret = rmrr_identity_mapping(source, 0, rmrr,
+                                            XEN_DOMCTL_PCIDEV_RDM_DEFAULT);
                 if ( ret != -ENOENT )
                     return ret;
             }
@@ -2258,7 +2274,7 @@ static int reassign_device_ownership(
 }
 
 static int intel_iommu_assign_device(
-    struct domain *d, u8 devfn, struct pci_dev *pdev)
+    struct domain *d, u8 devfn, struct pci_dev *pdev, u32 flag)
 {
     struct acpi_rmrr_unit *rmrr;
     int ret = 0, i;
@@ -2287,7 +2303,7 @@ static int intel_iommu_assign_device(
              PCI_BUS(bdf) == bus &&
              PCI_DEVFN2(bdf) == devfn )
         {
-            ret = rmrr_identity_mapping(d, 1, rmrr);
+            ret = rmrr_identity_mapping(d, 1, rmrr, flag);
             if ( ret )
             {
                 reassign_device_ownership(d, hardware_domain, devfn, pdev);
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index ca0e51e..e5ba7cb 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -493,6 +493,10 @@ DEFINE_XEN_GUEST_HANDLE(xen_domctl_sendtrigger_t);
 /* XEN_DOMCTL_deassign_device */
 struct xen_domctl_assign_device {
     uint32_t  machine_sbdf;   /* machine PCI ID of assigned device */
+    /* IN */
+#define XEN_DOMCTL_PCIDEV_RDM_TRY       0
+#define XEN_DOMCTL_PCIDEV_RDM_FORCE     1
+    uint32_t  sbdf_flag;   /* flag of assigned device */
 };
 typedef struct xen_domctl_assign_device xen_domctl_assign_device_t;
 DEFINE_XEN_GUEST_HANDLE(xen_domctl_assign_device_t);
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 8565b82..0d10b3d 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -129,7 +129,7 @@ struct iommu_ops {
     int (*add_device)(u8 devfn, device_t *dev);
     int (*enable_device)(device_t *dev);
     int (*remove_device)(u8 devfn, device_t *dev);
-    int (*assign_device)(struct domain *, u8 devfn, device_t *dev);
+    int (*assign_device)(struct domain *, u8 devfn, device_t *dev, u32 flag);
     int (*reassign_device)(struct domain *s, struct domain *t,
                            u8 devfn, device_t *dev);
 #ifdef HAS_PCI
-- 
1.9.1