| Message ID | 20200626071859.6827-1-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [kvm-unit-tests] x86: map bottom 2G 1:1 into page tables | expand |
diff --git a/lib/x86/vm.c b/lib/x86/vm.c index edbbe82..2bc2a39 100644 --- a/lib/x86/vm.c +++ b/lib/x86/vm.c @@ -154,8 +154,7 @@ void *setup_mmu(phys_addr_t end_of_memory) if (end_of_memory > (1ul << 31)) end_of_memory = (1ul << 31); - /* 0 - 2G memory, 2G-3G valloc area, 3G-4G mmio */ - setup_mmu_range(cr3, 0, end_of_memory); + setup_mmu_range(cr3, 0, (2ul << 30)); setup_mmu_range(cr3, 3ul << 30, (1ul << 30)); init_alloc_vpage((void*)(3ul << 30)); #endif
Right now only addresses up to the highest RAM memory address are are mapped 1:1 into the 32-bit page tables, but this also excludes ACPI-reserved areas that are higher than the highest RAM memory address. Depending on the memory layout, this may prevent the tests from accessing the ACPI tables after setup_vm. Unconditionally including the bottom 2G of memory fixes that. We do rely on the ACPI tables being in the first 2GB of memory, which is not necessarily true on bare metal; fixing that requires adding calls to something like Linux's kmap/kunmap. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- lib/x86/vm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)