[DOM0 KERNELS] pciback: Fix SR-IOV VF passthrough

[Keir Fraser <keir.fraser@eu.citrix.com>]

[-- Attachment #1: Type: text/plain, Size: 571 bytes --]

Vendor/device and BAR fields in a VF's host-level PCI config space are dummy
and must always be virtualised/emulated. Implement this in pciback by always
extracting the values installed in dom0 kernel's own PCI structures, rather
than interrogating the underlying PCI config space directly.

AFAIK, this patch should apply to any kernel that implements pciback: That
includes pv_ops, SLES, and the XS/XCP kernels. It should be applied to all
of them. It is already applied to linux-2.6.18-xen.hg as 998:693c40564c8d.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>


[-- Attachment #2: 00-pciback --]
[-- Type: application/octet-stream, Size: 3000 bytes --]

diff --git a/drivers/xen/pciback/conf_space_header.c b/drivers/xen/pciback/conf_space_header.c
index 3ae7da1..66a46dd 100644
--- a/drivers/xen/pciback/conf_space_header.c
+++ b/drivers/xen/pciback/conf_space_header.c
@@ -74,17 +74,7 @@ static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data)
 	/* A write to obtain the length must happen as a 32-bit write.
 	 * This does not (yet) support writing individual bytes
 	 */
-	if (value == ~PCI_ROM_ADDRESS_ENABLE)
-		bar->which = 1;
-	else {
-		u32 tmpval;
-		pci_read_config_dword(dev, offset, &tmpval);
-		if (tmpval != bar->val && value == bar->val) {
-			/* Allow restoration of bar value. */
-			pci_write_config_dword(dev, offset, bar->val);
-		}
-		bar->which = 0;
-	}
+	bar->which = (value == ~PCI_ROM_ADDRESS_ENABLE);
 
 	/* Do we need to support enabling/disabling the rom address here? */
 
@@ -108,17 +98,7 @@ static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data)
 	/* A write to obtain the length must happen as a 32-bit write.
 	 * This does not (yet) support writing individual bytes
 	 */
-	if (value == ~0)
-		bar->which = 1;
-	else {
-		u32 tmpval;
-		pci_read_config_dword(dev, offset, &tmpval);
-		if (tmpval != bar->val && value == bar->val) {
-			/* Allow restoration of bar value. */
-			pci_write_config_dword(dev, offset, bar->val);
-		}
-		bar->which = 0;
-	}
+	bar->which = (value == ~0);
 
 	return 0;
 }
@@ -126,6 +106,10 @@ static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data)
 static int bar_read(struct pci_dev *dev, int offset, u32 * value, void *data)
 {
 	struct pci_bar_info *bar = data;
+	int idx = (offset - 0x10) >> 2;
+
+	if (idx > PCI_STD_RESOURCE_END )
+		idx = PCI_ROM_RESOURCE;
 
 	if (unlikely(!bar)) {
 		printk(KERN_WARNING "pciback: driver data not found for %s\n",
@@ -133,7 +117,8 @@ static int bar_read(struct pci_dev *dev, int offset, u32 * value, void *data)
 		return XEN_PCI_ERR_op_failed;
 	}
 
-	*value = bar->which ? bar->len_val : bar->val;
+	*value = bar->which ? ~(pci_resource_len(dev, idx)-1) : pci_resource_start(dev, idx);
+	*value |= pci_resource_flags(dev, idx) & 0xf;
 
 	return 0;
 }
@@ -194,6 +179,22 @@ static int interrupt_read(struct pci_dev *dev, int offset, u8 * value,
 	return 0;
 }
 
+static int vendor_read(struct pci_dev *dev, int offset, u16 * value,
+		       void *data)
+{
+	*value = dev->vendor;
+
+	return 0;
+}
+
+static int device_read(struct pci_dev *dev, int offset, u16 * value,
+		       void *data)
+{
+	*value = dev->device;
+
+	return 0;
+}
+
 static int bist_write(struct pci_dev *dev, int offset, u8 value, void *data)
 {
 	u8 cur_value;
@@ -213,6 +214,16 @@ out:
 
 static const struct config_field header_common[] = {
 	{
+	 .offset    = PCI_VENDOR_ID,
+	 .size      = 2,
+	 .u.w.read  = vendor_read
+	},
+	{
+	 .offset    = PCI_DEVICE_ID,
+	 .size      = 2,
+	 .u.w.read  = device_read
+	},
+	{
 	 .offset    = PCI_COMMAND,
 	 .size      = 2,
 	 .u.w.read  = pciback_read_config_word,

[-- Attachment #3: Type: text/plain, Size: 138 bytes --]

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel