From 6b39271746de131366a14bcf04f5740cdc4abdef Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 22 Apr 2013 14:10:42 +0930 Subject: lguest: map Switcher below fixmap. Now we've adjusted all the code, we can simply set switcher_addr to wherever it needs to go below the fixmaps, rather than asserting that it should be so. With large NR_CPUS and PAE, people were hitting the "mapping switcher would thwack fixmap" message. Reported-by: Paul Bolle Signed-off-by: Rusty Russell --- drivers/lguest/core.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) (limited to 'drivers/lguest') diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index 7e1d7ee36478..0bf1e4edf04d 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -83,18 +83,13 @@ static __init int map_switcher(void) } } - switcher_addr = SWITCHER_ADDR; - /* - * First we check that the Switcher won't overlap the fixmap area at - * the top of memory. It's currently nowhere near, but it could have - * very strange effects if it ever happened. + * We place the Switcher underneath the fixmap area, which is the + * highest virtual address we can get. This is important, since we + * tell the Guest it can't access this memory, so we want its ceiling + * as high as possible. */ - if (switcher_addr + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){ - err = -ENOMEM; - printk("lguest: mapping switcher would thwack fixmap\n"); - goto free_pages; - } + switcher_addr = FIXADDR_START - (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE; /* * Now we reserve the "virtual memory area" we want. We might -- cgit v1.2.3