From 04b8dc85bf4a64517e3cf20e409eeaa503b15cc1 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 10 Mar 2015 19:07:00 +0000 Subject: arm64: KVM: Do not use pgd_index to index stage-2 pgd The kernel's pgd_index macro is designed to index a normal, page sized array. KVM is a bit diffferent, as we can use concatenated pages to have a bigger address space (for example 40bit IPA with 4kB pages gives us an 8kB PGD. In the above case, the use of pgd_index will always return an index inside the first 4kB, which makes a guest that has memory above 0x8000000000 rather unhappy, as it spins forever in a page fault, whist the host happilly corrupts the lower pgd. The obvious fix is to get our own kvm_pgd_index that does the right thing(tm). Tested on X-Gene with a hacked kvmtool that put memory at a stupidly high address. Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_mmu.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm/include/asm/kvm_mmu.h') diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index c57c41dc7e87..4cf48c3aca13 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -149,13 +149,14 @@ static inline bool kvm_s2pmd_readonly(pmd_t *pmd) (__boundary - 1 < (end) - 1)? __boundary: (end); \ }) +#define kvm_pgd_index(addr) pgd_index(addr) + static inline bool kvm_page_empty(void *ptr) { struct page *ptr_page = virt_to_page(ptr); return page_count(ptr_page) == 1; } - #define kvm_pte_table_empty(kvm, ptep) kvm_page_empty(ptep) #define kvm_pmd_table_empty(kvm, pmdp) kvm_page_empty(pmdp) #define kvm_pud_table_empty(kvm, pudp) (0) -- cgit v1.2.3