From 0a8a69dd77ddbd4513b21363021ecde7e1025502 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 22 Oct 2007 11:03:40 +1000 Subject: Virtio helper routines for a descriptor ringbuffer implementation These helper routines supply most of the virtqueue_ops for hypervisors which want to use a ring for virtio. Unlike the previous lguest implementation: 1) The rings are variable sized (2^n-1 elements). 2) They have an unfortunate limit of 65535 bytes per sg element. 3) The page numbers are always 64 bit (PAE anyone?) 4) They no longer place used[] on a separate page, just a separate cacheline. 5) We do a modulo on a variable. We could be tricky if we cared. 6) Interrupts and notifies are suppressed using flags within the rings. Users need only get the ring pages and provide a notify hook (KVM wants the guest to allocate the rings, lguest does it sanely). Signed-off-by: Rusty Russell Cc: Dor Laor --- arch/x86/lguest/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/lguest') diff --git a/arch/x86/lguest/Kconfig b/arch/x86/lguest/Kconfig index 0fabf87db99..44dccfd845f 100644 --- a/arch/x86/lguest/Kconfig +++ b/arch/x86/lguest/Kconfig @@ -2,6 +2,7 @@ config LGUEST_GUEST bool "Lguest guest support" select PARAVIRT depends on !X86_PAE + select VIRTIO_RING help Lguest is a tiny in-kernel hypervisor. Selecting this will allow your kernel to boot under lguest. This option will increase -- cgit v1.2.3-70-g09d2