From d3561b7fa0fb0fc583bab0eeda32bec9e4c4056d Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 7 Dec 2006 02:14:07 +0100 Subject: [PATCH] paravirt: header and stubs for paravirtualisation Create a paravirt.h header for all the critical operations which need to be replaced with hypervisor calls, and include that instead of defining native operations, when CONFIG_PARAVIRT. This patch does the dumbest possible replacement of paravirtualized instructions: calls through a "paravirt_ops" structure. Currently these are function implementations of native hardware: hypervisors will override the ops structure with their own variants. All the pv-ops functions are declared "fastcall" so that a specific register-based ABI is used, to make inlining assember easier. And: +From: Andy Whitcroft The paravirt ops introduce a 'weak' attribute onto memory_setup(). Code ordering leads to the following warnings on x86: arch/i386/kernel/setup.c:651: warning: weak declaration of `memory_setup' after first use results in unspecified behavior Move memory_setup() to avoid this. Signed-off-by: Rusty Russell Signed-off-by: Chris Wright Signed-off-by: Andi Kleen Cc: Jeremy Fitzhardinge Cc: Zachary Amsden Signed-off-by: Andrew Morton Signed-off-by: Andy Whitcroft --- arch/i386/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/i386/Kconfig') diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig index 1f0f7b60995..bb1fa061c6c 100644 --- a/arch/i386/Kconfig +++ b/arch/i386/Kconfig @@ -182,6 +182,17 @@ config X86_ES7000 endchoice +config PARAVIRT + bool "Paravirtualization support (EXPERIMENTAL)" + depends on EXPERIMENTAL + help + Paravirtualization is a way of running multiple instances of + Linux on the same machine, under a hypervisor. This option + changes the kernel so it can modify itself when it is run + under a hypervisor, improving performance significantly. + However, when run without a hypervisor the kernel is + theoretically slower. If in doubt, say N. + config ACPI_SRAT bool default y -- cgit v1.2.3