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arm64: KVM: Do not use pgd_index to index stage-2 pgd

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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@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Marc Zyngier
2015-03-10 19:07:00 +00:00
committed by Christoffer Dall
parent a987370f8e
commit 04b8dc85bf
3 changed files with 8 additions and 5 deletions
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8
arch/arm/kvm/mmu.c
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@@ -290,7 +290,7 @@ 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))
@@ -355,7 +355,7 @@ 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);
@@ -830,7 +830,7 @@ static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache
pgd_t *pgd;
pud_t *pud;
pgd = kvm->arch.pgd + pgd_index(addr);
pgd = kvm->arch.pgd + kvm_pgd_index(addr);
if (WARN_ON(pgd_none(*pgd))) {
if (!cache)
return NULL;
@@ -1120,7 +1120,7 @@ static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
pgd_t *pgd;
phys_addr_t next;
pgd = kvm->arch.pgd + pgd_index(addr);
pgd = kvm->arch.pgd + kvm_pgd_index(addr);
do {
/*
* Release kvm_mmu_lock periodically if the memory region is