[RFC][v2][PATCH 07/14] 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'. And 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.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
 xen/arch/x86/mm/p2m.c                       |  8 +++++++-
 xen/drivers/passthrough/amd/pci_amd_iommu.c |  3 ++-
 xen/drivers/passthrough/arm/smmu.c          |  2 +-
 xen/drivers/passthrough/device_tree.c       |  3 ++-
 xen/drivers/passthrough/pci.c               |  9 +++++----
 xen/drivers/passthrough/vtd/iommu.c         | 20 ++++++++++++--------
 xen/include/asm-x86/p2m.h                   |  2 +-
 xen/include/public/domctl.h                 |  5 +++++
 xen/include/xen/iommu.h                     |  2 +-
 9 files changed, 36 insertions(+), 18 deletions(-)

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 3574521..89473b9 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -899,7 +899,7 @@ int set_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn,
 }
 
 int set_identity_p2m_entry(struct domain *d, unsigned long gfn,
-                           p2m_access_t p2ma)
+                           p2m_access_t p2ma, u32 flag)
 {
     p2m_type_t p2mt;
     p2m_access_t a;
@@ -921,6 +921,12 @@ int set_identity_p2m_entry(struct domain *d, unsigned long gfn,
         printk(XENLOG_G_WARNING
                "Cannot identity map d%d:%lx, already mapped to %lx.\n",
                d->domain_id, gfn, mfn_x(mfn));
+
+        if ( flag == XEN_DOMCTL_DEV_RDM_RELAXED )
+        {
+            ret = 0;
+            printk(XENLOG_G_WARNING "Some devices may work failed .\n");
+        }
     }
 
     gfn_unlock(p2m, gfn, 0);
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/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c
index 6cc4394..9a667e9 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -2605,7 +2605,7 @@ static void arm_smmu_destroy_iommu_domain(struct iommu_domain *domain)
 }
 
 static int arm_smmu_assign_dev(struct domain *d, u8 devfn,
-			       struct device *dev)
+			       struct device *dev, u32 flag)
 {
 	struct iommu_domain *domain;
 	struct arm_smmu_xen_domain *xen_domain;
diff --git a/xen/drivers/passthrough/device_tree.c b/xen/drivers/passthrough/device_tree.c
index 5d3842a..d4ff7f0 100644
--- a/xen/drivers/passthrough/device_tree.c
+++ b/xen/drivers/passthrough/device_tree.c
@@ -52,7 +52,8 @@ int iommu_assign_dt_device(struct domain *d, struct dt_device_node *dev)
             goto fail;
     }
 
-    rc = hd->platform_ops->assign_device(d, 0, dt_to_dev(dev));
+    rc = hd->platform_ops->assign_device(d, 0, dt_to_dev(dev),
+                                         XEN_DOMCTL_DEV_NO_RDM);
 
     if ( rc )
         goto fail;
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index 862e20f..c06f038 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -1338,7 +1338,7 @@ 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;
@@ -1374,7 +1374,7 @@ 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 )
@@ -1382,7 +1382,7 @@ 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),
@@ -1499,6 +1499,7 @@ int iommu_do_pci_domctl(
 {
     u16 seg;
     u8 bus, devfn;
+    u32 flag = XEN_DOMCTL_DEV_RDM_RELAXED;
     int ret = 0;
     uint32_t machine_sbdf;
 
@@ -1582,7 +1583,7 @@ int iommu_do_pci_domctl(
         devfn = PCI_DEVFN2(machine_sbdf);
 
         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 31ce1af..d7c9e1c 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1808,7 +1808,8 @@ static void iommu_set_pgd(struct domain *d)
 }
 
 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;
@@ -1856,7 +1857,7 @@ static int rmrr_identity_mapping(struct domain *d, bool_t map,
 
     while ( base_pfn < end_pfn )
     {
-        int err = set_identity_p2m_entry(d, base_pfn, p2m_access_rw);
+        int err = set_identity_p2m_entry(d, base_pfn, p2m_access_rw, flag);
 
         if ( err )
             return err;
@@ -1899,7 +1900,8 @@ 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_DEV_RDM_RELAXED);
             if ( ret )
                 dprintk(XENLOG_ERR VTDPREFIX, "d%d: RMRR mapping failed\n",
                         pdev->domain->domain_id);
@@ -1940,7 +1942,8 @@ 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_DEV_RDM_RELAXED);
     }
 
     return domain_context_unmap(pdev->domain, devfn, pdev);
@@ -2098,7 +2101,7 @@ 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_DEV_RDM_RELAXED);
         if ( ret )
             dprintk(XENLOG_ERR VTDPREFIX,
                      "IOMMU: mapping reserved region failed\n");
@@ -2241,7 +2244,8 @@ 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_DEV_RDM_RELAXED);
                 if ( ret != -ENOENT )
                     return ret;
             }
@@ -2265,7 +2269,7 @@ 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;
@@ -2294,7 +2298,7 @@ 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/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 95b6266..a80b4f8 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -545,7 +545,7 @@ int clear_mmio_p2m_entry(struct domain *d, unsigned long gfn, mfn_t mfn);
 
 /* Set identity addresses in the p2m table (for pass-through) */
 int set_identity_p2m_entry(struct domain *d, unsigned long gfn,
-                           p2m_access_t p2ma);
+                           p2m_access_t p2ma, u32 flag);
 
 /* Add foreign mapping to the guest's p2m table. */
 int p2m_add_foreign(struct domain *tdom, unsigned long fgfn,
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 0c0ea4a..203c80e 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -499,6 +499,11 @@ struct xen_domctl_assign_device {
             XEN_GUEST_HANDLE_64(char) path; /* path to the device tree node */
         } dt;
     } u;
+    /* IN */
+#define XEN_DOMCTL_DEV_NO_RDM           0
+#define XEN_DOMCTL_DEV_RDM_RELAXED      1
+#define XEN_DOMCTL_DEV_RDM_STRICT       2
+    uint32_t  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 e2f584d..02b2b02 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -140,7 +140,7 @@ 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