bitkeeper revision 1.1159.1.158 (41499106LOJstE56FhydVjOBF9ioOQ)

Improve configuration of virtual device drivers in XenLinux.

4 files changed, 73 insertions, 9 deletions

diff --git a/linux-2.6.8.1-xen-sparse/arch/xen/Kconfig b/linux-2.6.8.1-xen-sparse/arch/xen/Kconfig
index 2bbe0229b4..a7e3994e10 100644
--- a/linux-2.6.8.1-xen-sparse/arch/xen/Kconfig
+++ b/linux-2.6.8.1-xen-sparse/arch/xen/Kconfig
@@ -31,9 +31,68 @@ config XEN_PRIVILEGED_GUEST
 	  Support for privileged operation (domain 0)
 
 config XEN_PHYSDEV_ACCESS
-	bool "Device-driver domain (physical device access)"
+	bool "Physical device access"
+	default y if XEN_PRIVILEGED_GUEST
+	default n if !XEN_PRIVILEGED_GUEST
 	help
-	  Device-driver domain (physical device access)
+	  Assume access is available to physical hardware devices
+          (e.g., hard drives, network cards). This allows you to configure
+          such devices and also includes some low-level support that is
+          otherwise not compiled into the kernel.
+
+config XEN_BLKDEV_BACKEND
+        bool "Block-device backend driver"
+        default y if XEN_PHYSDEV_ACCESS
+        default n if !XEN_PHYSDEV_ACCESS
+        help
+          The block-device backend driver allows the kernel to export its
+          block devices to other guests via a high-performance shared-memory
+          interface.
+
+config XEN_NETDEV_BACKEND
+        bool "Network-device backend driver"
+        default y if XEN_PHYSDEV_ACCESS
+        default n if !XEN_PHYSDEV_ACCESS
+        help
+          The network-device backend driver allows the kernel to export its
+          network devices to other guests via a high-performance shared-memory
+          interface.
+
+config XEN_BLKDEV_FRONTEND
+        bool "Block-device frontend driver"
+        default y
+        help
+          The block-device frontend driver allows the kernel to access block
+          devices mounted within another guest OS. Unless you are building a
+          dedicated device-driver domain, or your master control domain
+          (domain 0), then you almost certainly want to say Y here.
+
+config XEN_NETDEV_FRONTEND
+        bool "Network-device frontend driver"
+        default y
+        help
+          The network-device frontend driver allows the kernel to access
+          network interfaces within another guest OS. Unless you are building a
+          dedicated device-driver domain, or your master control domain
+          (domain 0), then you almost certainly want to say Y here.
+
+if XEN_NETDEV_FRONTEND
+config XEN_NETDEV_FRONTEND_PIPELINED_TRANSMITTER
+        bool "Pipelined transmitter (DANGEROUS)"
+        default n
+        help
+          The driver will assume that the backend is pipelining packets for
+          transmission: whenever packets are pending in the remote backend,
+          the driver will not send asynchronous notifications when it queues
+          additional packets for transmission.
+          If the backend is a dumb domain, such as a transparent Ethernet
+          bridge with no local IP interface, it is safe to say Y here to get
+          slightly lower network overhead.
+          If the backend has a local IP interface; or may be doing smart things
+          like reassembling packets to perform firewall filtering; or if you
+          are unsure; or if you experience network hangs when this option is
+          enabled; then you must say N here.
+endif
 
 config XEN_WRITABLE_PAGETABLES
 	bool "Use writable pagetables"
@@ -49,8 +108,8 @@ config FOREIGN_PAGES
 
 config PAGESIZED_SKBS
 	bool
-	default y if XEN_PHYSDEV_ACCESS
-	default n if !XEN_PHYSDEV_ACCESS
+	default y if XEN_NETDEV_BACKEND
+	default n if !XEN_NETDEV_BACKEND
 
 #config VT
 #	bool
diff --git a/linux-2.6.8.1-xen-sparse/arch/xen/configs/xen0_defconfig b/linux-2.6.8.1-xen-sparse/arch/xen/configs/xen0_defconfig
index 75fac7e487..a118d649cc 100644
--- a/linux-2.6.8.1-xen-sparse/arch/xen/configs/xen0_defconfig
+++ b/linux-2.6.8.1-xen-sparse/arch/xen/configs/xen0_defconfig
@@ -10,6 +10,11 @@ CONFIG_NO_IDLE_HZ=y
 #
 CONFIG_XEN_PRIVILEGED_GUEST=y
 CONFIG_XEN_PHYSDEV_ACCESS=y
+CONFIG_XEN_BLKDEV_BACKEND=y
+CONFIG_XEN_NETDEV_BACKEND=y
+CONFIG_XEN_BLKDEV_FRONTEND=y
+CONFIG_XEN_NETDEV_FRONTEND=y
+# CONFIG_XEN_NETDEV_FRONTEND_PIPELINED_TRANSMITTER is not set
 CONFIG_XEN_WRITABLE_PAGETABLES=y
 CONFIG_FOREIGN_PAGES=y
 CONFIG_PAGESIZED_SKBS=y
diff --git a/linux-2.6.8.1-xen-sparse/arch/xen/configs/xenU_defconfig b/linux-2.6.8.1-xen-sparse/arch/xen/configs/xenU_defconfig
index 8d0d9fc5a3..a3efc64d58 100644
--- a/linux-2.6.8.1-xen-sparse/arch/xen/configs/xenU_defconfig
+++ b/linux-2.6.8.1-xen-sparse/arch/xen/configs/xenU_defconfig
@@ -10,6 +10,11 @@ CONFIG_NO_IDLE_HZ=y
 #
 # CONFIG_XEN_PRIVILEGED_GUEST is not set
 # CONFIG_XEN_PHYSDEV_ACCESS is not set
+# CONFIG_XEN_BLKDEV_BACKEND is not set
+# CONFIG_XEN_NETDEV_BACKEND is not set
+CONFIG_XEN_BLKDEV_FRONTEND=y
+CONFIG_XEN_NETDEV_FRONTEND=y
+# CONFIG_XEN_NETDEV_FRONTEND_PIPELINED_TRANSMITTER is not set
 CONFIG_XEN_WRITABLE_PAGETABLES=y
 CONFIG_FOREIGN_PAGES=y
 # CONFIG_PAGESIZED_SKBS is not set
diff --git a/linux-2.6.8.1-xen-sparse/arch/xen/i386/mm/ioremap.c b/linux-2.6.8.1-xen-sparse/arch/xen/i386/mm/ioremap.c
index 1efdacd8c2..8a12a5c93c 100644
--- a/linux-2.6.8.1-xen-sparse/arch/xen/i386/mm/ioremap.c
+++ b/linux-2.6.8.1-xen-sparse/arch/xen/i386/mm/ioremap.c
@@ -337,8 +337,6 @@ void __init bt_iounmap(void *addr, unsigned long size)
 
 #endif /* CONFIG_XEN_PHYSDEV_ACCESS */
 
-#if defined(CONFIG_XEN_PRIVILEGED_GUEST)
-
 /* These hacky macros avoid phys->machine translations. */
 #define __direct_pte(x) ((pte_t) { (x) } )
 #define __direct_mk_pte(page_nr,pgprot) \
@@ -481,6 +479,3 @@ int direct_remap_area_pages(struct mm_struct *mm,
     
     return 0;
 }
-
-
-#endif /* CONFIG_XEN_PRIVILEGED_GUEST */