apohw: port A0B36APO labs matrix keyboard hardware emulation to QEMU 2.1.

[lisovros/qemu_apohw.git] / qemu-doc.texi

diff --git a/qemu-doc.texi b/qemu-doc.texi
index ad92c85cba80d5898955c819a29ff94156a52f68..2b232ae8b732e1977d61fabb27bc19c06a6bec06 100644 (file)
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -590,7 +590,7 @@ check -r all} is required, which may take some time.
 This option can only be enabled if @code{compat=1.1} is specified.
 
 @item nocow
-If this option is set to @code{on}, it will trun off COW of the file. It's only
+If this option is set to @code{on}, it will turn off COW of the file. It's only
 valid on btrfs, no effect on other file systems.
 
 Btrfs has low performance when hosting a VM image file, even more when the guest
@@ -603,7 +603,7 @@ does.
 Note: this option is only valid to new or empty files. If there is an existing
 file which is COW and has data blocks already, it couldn't be changed to NOCOW
 by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if
-the NOCOW flag is set or not (Capitabl 'C' is NOCOW flag).
+the NOCOW flag is set or not (Capital 'C' is NOCOW flag).
 
 @end table
 
@@ -1205,9 +1205,16 @@ In order to check that the user mode network is working, you can ping
 the address 10.0.2.2 and verify that you got an address in the range
 10.0.2.x from the QEMU virtual DHCP server.
 
-Note that @code{ping} is not supported reliably to the internet as it
-would require root privileges. It means you can only ping the local
-router (10.0.2.2).
+Note that ICMP traffic in general does not work with user mode networking.
+@code{ping}, aka. ICMP echo, to the local router (10.0.2.2) shall work,
+however. If you're using QEMU on Linux >= 3.0, it can use unprivileged ICMP
+ping sockets to allow @code{ping} to the Internet. The host admin has to set
+the ping_group_range in order to grant access to those sockets. To allow ping
+for GID 100 (usually users group):
+
+@example
+echo 100 100 > /proc/sys/net/ipv4/ping_group_range
+@end example
 
 When using the built-in TFTP server, the router is also the TFTP
 server.