From 3249b7e1df6380e9d7bb3238f64f445bf614f787 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Fri, 26 Feb 2010 17:16:01 +0000 Subject: x86, vmi: Disable highmem PTE allocation even when CONFIG_HIGHPTE=y Preventing HIGHPTE allocations under VMI will allow us to remove the kmap_atomic_pte paravirt op. Signed-off-by: Ian Campbell LKML-Reference: <1267204562-11844-2-git-send-email-ian.campbell@citrix.com> Acked-by: Alok Kataria Cc: Ingo Molnar Cc: Jeremy Fitzhardinge Signed-off-by: H. Peter Anvin --- arch/x86/kernel/vmi_32.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) (limited to 'arch/x86/kernel/vmi_32.c') diff --git a/arch/x86/kernel/vmi_32.c b/arch/x86/kernel/vmi_32.c index d430e4c3019..58aca86193e 100644 --- a/arch/x86/kernel/vmi_32.c +++ b/arch/x86/kernel/vmi_32.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -272,19 +273,11 @@ static void *vmi_kmap_atomic_pte(struct page *page, enum km_type type) void *va = kmap_atomic(page, type); /* - * Internally, the VMI ROM must map virtual addresses to physical - * addresses for processing MMU updates. By the time MMU updates - * are issued, this information is typically already lost. - * Fortunately, the VMI provides a cache of mapping slots for active - * page tables. - * - * We use slot zero for the linear mapping of physical memory, and - * in HIGHPTE kernels, slot 1 and 2 for KM_PTE0 and KM_PTE1. - * - * args: SLOT VA COUNT PFN + * We disable highmem allocations for page tables so we should never + * see any calls to kmap_atomic_pte on a highmem page. */ - BUG_ON(type != KM_PTE0 && type != KM_PTE1); - vmi_ops.set_linear_mapping((type - KM_PTE0)+1, va, 1, page_to_pfn(page)); + + BUG_ON(PageHighmem(page)); return va; } @@ -640,6 +633,12 @@ static inline int __init activate_vmi(void) u64 reloc; const struct vmi_relocation_info *rel = (struct vmi_relocation_info *)&reloc; + /* + * Prevent page tables from being allocated in highmem, even if + * CONFIG_HIGHPTE is enabled. + */ + __userpte_alloc_gfp &= ~__GFP_HIGHMEM; + if (call_vrom_func(vmi_rom, vmi_init) != 0) { printk(KERN_ERR "VMI ROM failed to initialize!"); return 0; -- cgit v1.2.3