From 406a590ba105bfb7b67952f0a5f948e0d374e03e Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Mon, 22 Apr 2013 14:10:37 +0930 Subject: [PATCH] lguest: prepare to make SWITCHER_ADDR a variable. We currently use the whole top PGD entry for the switcher, but that's hitting the fixmap in some configurations (mainly, large NR_CPUS). Introduce a variable, currently set to the constant. Signed-off-by: Rusty Russell --- arch/x86/include/asm/lguest.h | 2 ++ drivers/lguest/core.c | 18 ++++++++++-------- drivers/lguest/x86/core.c | 4 ++-- 3 files changed, 14 insertions(+), 10 deletions(-) diff --git a/arch/x86/include/asm/lguest.h b/arch/x86/include/asm/lguest.h index 0d97deba1e35..85ecdb80d121 100644 --- a/arch/x86/include/asm/lguest.h +++ b/arch/x86/include/asm/lguest.h @@ -23,6 +23,8 @@ #else #define SWITCHER_ADDR 0xFFC00000 #endif +/* Where we map the Switcher, in both Host and Guest. */ +extern unsigned long switcher_addr; /* Found in switcher.S */ extern unsigned long default_idt_entries[]; diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index a5ebc0083d87..099252301132 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -20,7 +20,7 @@ #include #include "lg.h" - +unsigned long switcher_addr; static struct vm_struct *switcher_vma; static struct page **switcher_page; @@ -75,25 +75,27 @@ 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. */ - if (SWITCHER_ADDR + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){ + if (switcher_addr + (TOTAL_SWITCHER_PAGES+1)*PAGE_SIZE > FIXADDR_START){ err = -ENOMEM; printk("lguest: mapping switcher would thwack fixmap\n"); goto free_pages; } /* - * Now we reserve the "virtual memory area" we want: 0xFFC00000 - * (SWITCHER_ADDR). We might not get it in theory, but in practice - * it's worked so far. The end address needs +1 because __get_vm_area - * allocates an extra guard page, so we need space for that. + * Now we reserve the "virtual memory area" we want. We might + * not get it in theory, but in practice it's worked so far. + * The end address needs +1 because __get_vm_area allocates an + * extra guard page, so we need space for that. */ switcher_vma = __get_vm_area(TOTAL_SWITCHER_PAGES * PAGE_SIZE, - VM_ALLOC, SWITCHER_ADDR, SWITCHER_ADDR + VM_ALLOC, switcher_addr, switcher_addr + (TOTAL_SWITCHER_PAGES+1) * PAGE_SIZE); if (!switcher_vma) { err = -ENOMEM; @@ -103,7 +105,7 @@ static __init int map_switcher(void) /* * This code actually sets up the pages we've allocated to appear at - * SWITCHER_ADDR. map_vm_area() takes the vma we allocated above, the + * switcher_addr. map_vm_area() takes the vma we allocated above, the * kind of pages we're mapping (kernel pages), and a pointer to our * array of struct pages. It increments that pointer, but we don't * care. diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c index 4af12e1844d5..20fae765d600 100644 --- a/drivers/lguest/x86/core.c +++ b/drivers/lguest/x86/core.c @@ -59,14 +59,14 @@ static struct { /* Offset from where switcher.S was compiled to where we've copied it */ static unsigned long switcher_offset(void) { - return SWITCHER_ADDR - (unsigned long)start_switcher_text; + return switcher_addr - (unsigned long)start_switcher_text; } /* This cpu's struct lguest_pages. */ static struct lguest_pages *lguest_pages(unsigned int cpu) { return &(((struct lguest_pages *) - (SWITCHER_ADDR + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]); + (switcher_addr + SHARED_SWITCHER_PAGES*PAGE_SIZE))[cpu]); } static DEFINE_PER_CPU(struct lg_cpu *, lg_last_cpu);