3.16.7-ckt12 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Marc Zyngier <marc.zyngier@xxxxxxx>
commit 04b8dc85bf4a64517e3cf20e409eeaa503b15cc1 upstream.
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 <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
[ luis: backported to 3.16: used shannon's backport to 3.14 ]
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
arch/arm/include/asm/kvm_mmu.h | 3 ++-
arch/arm/kvm/mmu.c | 6 +++---
arch/arm64/include/asm/kvm_mmu.h | 2 ++
3 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index c02a8367dee4..8618badbbbbe 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -117,13 +117,14 @@ static inline void kvm_set_s2pmd_writable(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(ptep) kvm_page_empty(ptep)
#define kvm_pmd_table_empty(pmdp) kvm_page_empty(pmdp)
#define kvm_pud_table_empty(pudp) (0)
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index bbf6a127ef3c..c65db5d7ea92 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -194,7 +194,7 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp,
phys_addr_t addr = start, end = start + size;
phys_addr_t next;
- pgd = pgdp + pgd_index(addr);
+ pgd = pgdp + kvm_pgd_index(addr);
do {
next = kvm_pgd_addr_end(addr, end);
if (!pgd_none(*pgd))
@@ -264,7 +264,7 @@ static void stage2_flush_memslot(struct kvm *kvm,
phys_addr_t next;
pgd_t *pgd;
- pgd = kvm->arch.pgd + pgd_index(addr);
+ pgd = kvm->arch.pgd + kvm_pgd_index(addr);
do {
next = kvm_pgd_addr_end(addr, end);
stage2_flush_puds(kvm, pgd, addr, next);
@@ -649,7 +649,7 @@ static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache
pud_t *pud;
pmd_t *pmd;
- pgd = kvm->arch.pgd + pgd_index(addr);
+ pgd = kvm->arch.pgd + kvm_pgd_index(addr);
pud = pud_offset(pgd, addr);
if (pud_none(*pud)) {
if (!cache)
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 0d51874c838f..2067f4b75d13 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -69,6 +69,8 @@
#define PTRS_PER_S2_PGD (1 << (KVM_PHYS_SHIFT - PGDIR_SHIFT))
#define S2_PGD_ORDER get_order(PTRS_PER_S2_PGD * sizeof(pgd_t))
+#define kvm_pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_S2_PGD - 1))
+
int create_hyp_mappings(void *from, void *to);
int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
void free_boot_hyp_pgd(void);
--
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