1 From: jbeulich@novell.com
2 Subject: allow number of guest devices to be configurable
3 Patch-mainline: obsolete
5 ... and derive NR_DYNIRQS from this (rather than having a hard-coded
7 Similarly, allow the number of simultaneous transmits in netback to be
11 drivers/xen/Kconfig | 19 +++++++++++++++++++
12 drivers/xen/netback/netback.c | 3 ++-
13 include/asm-x86/mach-xen/asm/irq_vectors.h | 2 +-
14 3 files changed, 22 insertions(+), 2 deletions(-)
16 --- a/drivers/xen/Kconfig
17 +++ b/drivers/xen/Kconfig
18 @@ -74,6 +74,15 @@ config XEN_NETDEV_BACKEND
19 network devices to other guests via a high-performance shared-memory
22 +config XEN_NETDEV_TX_SHIFT
23 + int "Maximum simultaneous transmit requests (as a power of 2)"
24 + depends on XEN_NETDEV_BACKEND
28 + The maximum number transmits the driver can hold pending, expressed
29 + as the exponent of a power of 2.
31 config XEN_NETDEV_PIPELINED_TRANSMITTER
32 bool "Pipelined transmitter (DANGEROUS)"
33 depends on XEN_NETDEV_BACKEND
34 @@ -255,6 +264,16 @@ config XEN_SYSFS
36 Xen hypervisor attributes will show up under /sys/hypervisor/.
38 +config XEN_NR_GUEST_DEVICES
39 + int "Number of guest devices"
40 + range 0 4032 if 64BIT
42 + default 256 if XEN_BACKEND
45 + Specify the total number of virtual devices (i.e. both frontend
46 + and backend) that you want the kernel to be able to service.
49 prompt "Xen version compatibility"
50 default XEN_COMPAT_030002_AND_LATER
51 --- a/drivers/xen/netback/netback.c
52 +++ b/drivers/xen/netback/netback.c
53 @@ -74,7 +74,7 @@ static DECLARE_TASKLET(net_rx_tasklet, n
54 static struct timer_list net_timer;
55 static struct timer_list netbk_tx_pending_timer;
57 -#define MAX_PENDING_REQS 256
58 +#define MAX_PENDING_REQS (1U << CONFIG_XEN_NETDEV_TX_SHIFT)
60 static struct sk_buff_head rx_queue;
62 @@ -1196,6 +1196,7 @@ static void net_tx_action(unsigned long
63 net_tx_action_dealloc();
66 + BUILD_BUG_ON(MAX_SKB_FRAGS >= MAX_PENDING_REQS);
67 while (((NR_PENDING_REQS + MAX_SKB_FRAGS) < MAX_PENDING_REQS) &&
68 !list_empty(&net_schedule_list)) {
69 /* Get a netif from the list with work to do. */
70 --- a/include/asm-x86/mach-xen/asm/irq_vectors.h
71 +++ b/include/asm-x86/mach-xen/asm/irq_vectors.h
75 #define DYNIRQ_BASE (PIRQ_BASE + NR_PIRQS)
76 -#define NR_DYNIRQS 256
77 +#define NR_DYNIRQS (64 + CONFIG_XEN_NR_GUEST_DEVICES)
79 #define NR_IRQS (NR_PIRQS + NR_DYNIRQS)
80 #define NR_IRQ_VECTORS NR_IRQS