projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| c9c77b0b GKH |
1 | From 04b8dc85bf4a64517e3cf20e409eeaa503b15cc1 Mon Sep 17 00:00:00 2001 |
| 2 | From: Marc Zyngier <marc.zyngier@arm.com> | |
| 3 | Date: Tue, 10 Mar 2015 19:07:00 +0000 | |
| 4 | Subject: arm64: KVM: Do not use pgd_index to index stage-2 pgd | |
| 5 | ||
| 6 | From: Marc Zyngier <marc.zyngier@arm.com> | |
| 7 | ||
| 8 | commit 04b8dc85bf4a64517e3cf20e409eeaa503b15cc1 upstream. | |
| 9 | ||
| 10 | The kernel's pgd_index macro is designed to index a normal, page | |
| 11 | sized array. KVM is a bit diffferent, as we can use concatenated | |
| 12 | pages to have a bigger address space (for example 40bit IPA with | |
| 13 | 4kB pages gives us an 8kB PGD. | |
| 14 | ||
| 15 | In the above case, the use of pgd_index will always return an index | |
| 16 | inside the first 4kB, which makes a guest that has memory above | |
| 17 | 0x8000000000 rather unhappy, as it spins forever in a page fault, | |
| 18 | whist the host happilly corrupts the lower pgd. | |
| 19 | ||
| 20 | The obvious fix is to get our own kvm_pgd_index that does the right | |
| 21 | thing(tm). | |
| 22 | ||
| 23 | Tested on X-Gene with a hacked kvmtool that put memory at a stupidly | |
| 24 | high address. | |
| 25 | ||
| 26 | Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> | |
| 27 | Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> | |
| 28 | Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> | |
| 29 | Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> | |
| 30 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 31 | --- | |
| 32 | arch/arm/include/asm/kvm_mmu.h | 3 ++- | |
| 33 | arch/arm/kvm/mmu.c | 6 +++--- | |
| 34 | arch/arm64/include/asm/kvm_mmu.h | 2 ++ | |
| 35 | 3 files changed, 7 insertions(+), 4 deletions(-) | |
| 36 | ||
| 37 | --- a/arch/arm/include/asm/kvm_mmu.h | |
| 38 | +++ b/arch/arm/include/asm/kvm_mmu.h | |
| 39 | @@ -128,13 +128,14 @@ static inline void kvm_set_s2pmd_writabl | |
| 40 | (__boundary - 1 < (end) - 1)? __boundary: (end); \ | |
| 41 | }) | |
| 42 | ||
| 43 | +#define kvm_pgd_index(addr) pgd_index(addr) | |
| 44 | + | |
| 45 | static inline bool kvm_page_empty(void *ptr) | |
| 46 | { | |
| 47 | struct page *ptr_page = virt_to_page(ptr); | |
| 48 | return page_count(ptr_page) == 1; | |
| 49 | } | |
| 50 | ||
| 51 | - | |
| 52 | #define kvm_pte_table_empty(kvm, ptep) kvm_page_empty(ptep) | |
| 53 | #define kvm_pmd_table_empty(kvm, pmdp) kvm_page_empty(pmdp) | |
| 54 | #define kvm_pud_table_empty(kvm, pudp) (0) | |
| 55 | --- a/arch/arm/kvm/mmu.c | |
| 56 | +++ b/arch/arm/kvm/mmu.c | |
| 57 | @@ -251,7 +251,7 @@ static void unmap_range(struct kvm *kvm, | |
| 58 | phys_addr_t addr = start, end = start + size; | |
| 59 | phys_addr_t next; | |
| 60 | ||
| 61 | - pgd = pgdp + pgd_index(addr); | |
| 62 | + pgd = pgdp + kvm_pgd_index(addr); | |
| 63 | do { | |
| 64 | next = kvm_pgd_addr_end(addr, end); | |
| 65 | if (!pgd_none(*pgd)) | |
| 66 | @@ -316,7 +316,7 @@ static void stage2_flush_memslot(struct | |
| 67 | phys_addr_t next; | |
| 68 | pgd_t *pgd; | |
| 69 | ||
| 70 | - pgd = kvm->arch.pgd + pgd_index(addr); | |
| 71 | + pgd = kvm->arch.pgd + kvm_pgd_index(addr); | |
| 72 | do { | |
| 73 | next = kvm_pgd_addr_end(addr, end); | |
| 74 | stage2_flush_puds(kvm, pgd, addr, next); | |
| 75 | @@ -791,7 +791,7 @@ static pud_t *stage2_get_pud(struct kvm | |
| 76 | pgd_t *pgd; | |
| 77 | pud_t *pud; | |
| 78 | ||
| 79 | - pgd = kvm->arch.pgd + pgd_index(addr); | |
| 80 | + pgd = kvm->arch.pgd + kvm_pgd_index(addr); | |
| 81 | if (WARN_ON(pgd_none(*pgd))) { | |
| 82 | if (!cache) | |
| 83 | return NULL; | |
| 84 | --- a/arch/arm64/include/asm/kvm_mmu.h | |
| 85 | +++ b/arch/arm64/include/asm/kvm_mmu.h | |
| 86 | @@ -137,6 +137,8 @@ static inline void kvm_set_s2pmd_writabl | |
| 87 | #define PTRS_PER_S2_PGD (1 << PTRS_PER_S2_PGD_SHIFT) | |
| 88 | #define S2_PGD_ORDER get_order(PTRS_PER_S2_PGD * sizeof(pgd_t)) | |
| 89 | ||
| 90 | +#define kvm_pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_S2_PGD - 1)) | |
| 91 | + | |
| 92 | /* | |
| 93 | * If we are concatenating first level stage-2 page tables, we would have less | |
| 94 | * than or equal to 16 pointers in the fake PGD, because that's what the |