Merge tag 'vfio-v4.7-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Hide INTx on certain known broken devices (Alex Williamson)

 - Additional backdoor reset detection (Alex Williamson)

 - Remove unused iommudata reference (Alexey Kardashevskiy)

 - Use cfg_size to avoid probing extended config space (Alexey
   Kardashevskiy)

* tag 'vfio-v4.7-rc1' of git://github.com/awilliam/linux-vfio:
  vfio_pci: Test for extended capabilities if config space > 256 bytes
  vfio_iommu_spapr_tce: Remove unneeded iommu_group_get_iommudata
  vfio/pci: Add test for BAR restore
  vfio/pci: Hide broken INTx support from user

4 files changed, 84 insertions, 20 deletions

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 712a84978e97..188b1ff03f5f 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -113,6 +113,35 @@ static inline bool vfio_pci_is_vga(struct pci_dev *pdev)
 static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev);
 static void vfio_pci_disable(struct vfio_pci_device *vdev);
 
+/*
+ * INTx masking requires the ability to disable INTx signaling via PCI_COMMAND
+ * _and_ the ability detect when the device is asserting INTx via PCI_STATUS.
+ * If a device implements the former but not the latter we would typically
+ * expect broken_intx_masking be set and require an exclusive interrupt.
+ * However since we do have control of the device's ability to assert INTx,
+ * we can instead pretend that the device does not implement INTx, virtualizing
+ * the pin register to report zero and maintaining DisINTx set on the host.
+ */
+static bool vfio_pci_nointx(struct pci_dev *pdev)
+{
+        switch (pdev->vendor) {
+        case PCI_VENDOR_ID_INTEL:
+                switch (pdev->device) {
+                /* All i40e (XL710/X710) 10/20/40GbE NICs */
+                case 0x1572:
+                case 0x1574:
+                case 0x1580 ... 0x1581:
+                case 0x1583 ... 0x1589:
+                case 0x37d0 ... 0x37d2:
+                        return true;
+                default:
+                        return false;
+                }
+        }
+
+        return false;
+}
+
 static int vfio_pci_enable(struct vfio_pci_device *vdev)
 {
         struct pci_dev *pdev = vdev->pdev;
@@ -136,23 +165,29 @@ static int vfio_pci_enable(struct vfio_pci_device *vdev)
                 pr_debug("%s: Couldn't store %s saved state\n",
                          __func__, dev_name(&pdev->dev));
 
-        ret = vfio_config_init(vdev);
-        if (ret) {
-                kfree(vdev->pci_saved_state);
-                vdev->pci_saved_state = NULL;
-                pci_disable_device(pdev);
-                return ret;
+        if (likely(!nointxmask)) {
+                if (vfio_pci_nointx(pdev)) {
+                        dev_info(&pdev->dev, "Masking broken INTx support\n");
+                        vdev->nointx = true;
+                        pci_intx(pdev, 0);
+                } else
+                        vdev->pci_2_3 = pci_intx_mask_supported(pdev);
         }
 
-        if (likely(!nointxmask))
-                vdev->pci_2_3 = pci_intx_mask_supported(pdev);
-
         pci_read_config_word(pdev, PCI_COMMAND, &cmd);
         if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
                 cmd &= ~PCI_COMMAND_INTX_DISABLE;
                 pci_write_config_word(pdev, PCI_COMMAND, cmd);
         }
 
+        ret = vfio_config_init(vdev);
+        if (ret) {
+                kfree(vdev->pci_saved_state);
+                vdev->pci_saved_state = NULL;
+                pci_disable_device(pdev);
+                return ret;
+        }
+
         msix_pos = pdev->msix_cap;
         if (msix_pos) {
                 u16 flags;
@@ -304,7 +339,7 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
         if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
                 u8 pin;
                 pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
-                if (IS_ENABLED(CONFIG_VFIO_PCI_INTX) && pin)
+                if (IS_ENABLED(CONFIG_VFIO_PCI_INTX) && !vdev->nointx && pin)
                         return 1;
 
         } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index 142c533efec7..93601407dab8 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -408,6 +408,7 @@ static void vfio_bar_restore(struct vfio_pci_device *vdev)
 {
         struct pci_dev *pdev = vdev->pdev;
         u32 *rbar = vdev->rbar;
+        u16 cmd;
         int i;
 
         if (pdev->is_virtfn)
@@ -420,6 +421,12 @@ static void vfio_bar_restore(struct vfio_pci_device *vdev)
                 pci_user_write_config_dword(pdev, i, *rbar);
 
         pci_user_write_config_dword(pdev, PCI_ROM_ADDRESS, *rbar);
+
+        if (vdev->nointx) {
+                pci_user_read_config_word(pdev, PCI_COMMAND, &cmd);
+                cmd |= PCI_COMMAND_INTX_DISABLE;
+                pci_user_write_config_word(pdev, PCI_COMMAND, cmd);
+        }
 }
 
 static __le32 vfio_generate_bar_flags(struct pci_dev *pdev, int bar)
@@ -515,6 +522,23 @@ static int vfio_basic_config_read(struct vfio_pci_device *vdev, int pos,
         return count;
 }
 
+/* Test whether BARs match the value we think they should contain */
+static bool vfio_need_bar_restore(struct vfio_pci_device *vdev)
+{
+        int i = 0, pos = PCI_BASE_ADDRESS_0, ret;
+        u32 bar;
+
+        for (; pos <= PCI_BASE_ADDRESS_5; i++, pos += 4) {
+                if (vdev->rbar[i]) {
+                        ret = pci_user_read_config_dword(vdev->pdev, pos, &bar);
+                        if (ret || vdev->rbar[i] != bar)
+                                return true;
+                }
+        }
+
+        return false;
+}
+
 static int vfio_basic_config_write(struct vfio_pci_device *vdev, int pos,
                                    int count, struct perm_bits *perm,
                                    int offset, __le32 val)
@@ -553,7 +577,8 @@ static int vfio_basic_config_write(struct vfio_pci_device *vdev, int pos,
                  * SR-IOV devices will trigger this, but we catch them later
                  */
                 if ((new_mem && virt_mem && !phys_mem) ||
-                    (new_io && virt_io && !phys_io))
+                    (new_io && virt_io && !phys_io) ||
+                    vfio_need_bar_restore(vdev))
                         vfio_bar_restore(vdev);
         }
 
@@ -1124,9 +1149,12 @@ static int vfio_cap_len(struct vfio_pci_device *vdev, u8 cap, u8 pos)
                         return pcibios_err_to_errno(ret);
 
                 if (PCI_X_CMD_VERSION(word)) {
-                        /* Test for extended capabilities */
-                        pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword);
-                        vdev->extended_caps = (dword != 0);
+                        if (pdev->cfg_size > PCI_CFG_SPACE_SIZE) {
+                                /* Test for extended capabilities */
+                                pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE,
+                                                      &dword);
+                                vdev->extended_caps = (dword != 0);
+                        }
                         return PCI_CAP_PCIX_SIZEOF_V2;
                 } else
                         return PCI_CAP_PCIX_SIZEOF_V0;
@@ -1138,9 +1166,11 @@ static int vfio_cap_len(struct vfio_pci_device *vdev, u8 cap, u8 pos)
 
                 return byte;
         case PCI_CAP_ID_EXP:
-                /* Test for extended capabilities */
-                pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword);
-                vdev->extended_caps = (dword != 0);
+                if (pdev->cfg_size > PCI_CFG_SPACE_SIZE) {
+                        /* Test for extended capabilities */
+                        pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword);
+                        vdev->extended_caps = (dword != 0);
+                }
 
                 /* length based on version */
                 if ((pcie_caps_reg(pdev) & PCI_EXP_FLAGS_VERS) == 1)
@@ -1545,7 +1575,7 @@ int vfio_config_init(struct vfio_pci_device *vdev)
                 *(__le16 *)&vconfig[PCI_DEVICE_ID] = cpu_to_le16(pdev->device);
         }
 
-        if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX))
+        if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || vdev->nointx)
                 vconfig[PCI_INTERRUPT_PIN] = 0;
 
         ret = vfio_cap_init(vdev);
diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
index 8a7d546d18a0..016c14a1b454 100644
--- a/drivers/vfio/pci/vfio_pci_private.h
+++ b/drivers/vfio/pci/vfio_pci_private.h
@@ -83,6 +83,7 @@ struct vfio_pci_device {
         bool                    bardirty;
         bool                    has_vga;
         bool                    needs_reset;
+        bool                    nointx;
         struct pci_saved_state  *pci_saved_state;
         int                     refcnt;
         struct eventfd_ctx      *err_trigger;
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 3054e3fa63ac..80378ddadc5c 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -331,14 +331,12 @@ static void tce_iommu_free_table(struct iommu_table *tbl);
 static void tce_iommu_release(void *iommu_data)
 {
         struct tce_container *container = iommu_data;
-        struct iommu_table_group *table_group;
         struct tce_iommu_group *tcegrp;
         long i;
 
         while (tce_groups_attached(container)) {
                 tcegrp = list_first_entry(&container->group_list,
                                 struct tce_iommu_group, next);
-                table_group = iommu_group_get_iommudata(tcegrp->grp);
                 tce_iommu_detach_group(iommu_data, tcegrp->grp);
         }