Commit e8b9a055 authored by Oliver Upton's avatar Oliver Upton Committed by Paolo Bonzini

KVM: arm64: selftests: Align VA space allocator with TTBR0

An interesting feature of the Arm architecture is that the stage-1 MMU
supports two distinct VA regions, controlled by TTBR{0,1}_EL1. As KVM
selftests on arm64 only uses TTBR0_EL1, the VA space is constrained to
[0, 2^(va_bits-1)). This is different from other architectures that
allow for addressing low and high regions of the VA space from a single
page table.

KVM selftests' VA space allocator presumes the valid address range is
split between low and high memory based the MSB, which of course is a
poor match for arm64's TTBR0 region.

Allow architectures to override the default VA space layout. Make use of
the override to align vpages_valid with the behavior of TTBR0 on arm64.
Signed-off-by: default avatarOliver Upton <oliver.upton@linux.dev>
Message-Id: <20221207214809.489070-4-oliver.upton@linux.dev>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent eb561891
......@@ -408,6 +408,7 @@ void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags);
void vm_mem_region_move(struct kvm_vm *vm, uint32_t slot, uint64_t new_gpa);
void vm_mem_region_delete(struct kvm_vm *vm, uint32_t slot);
struct kvm_vcpu *__vm_vcpu_add(struct kvm_vm *vm, uint32_t vcpu_id);
void vm_populate_vaddr_bitmap(struct kvm_vm *vm);
vm_vaddr_t vm_vaddr_unused_gap(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
vm_vaddr_t vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min);
vm_vaddr_t __vm_vaddr_alloc(struct kvm_vm *vm, size_t sz, vm_vaddr_t vaddr_min,
......
......@@ -541,3 +541,13 @@ void kvm_selftest_arch_init(void)
*/
guest_modes_append_default();
}
void vm_vaddr_populate_bitmap(struct kvm_vm *vm)
{
/*
* arm64 selftests use only TTBR0_EL1, meaning that the valid VA space
* is [0, 2^(64 - TCR_EL1.T0SZ)).
*/
sparsebit_set_num(vm->vpages_valid, 0,
(1ULL << vm->va_bits) >> vm->page_shift);
}
......@@ -186,6 +186,15 @@ const struct vm_guest_mode_params vm_guest_mode_params[] = {
_Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params) == NUM_VM_MODES,
"Missing new mode params?");
__weak void vm_vaddr_populate_bitmap(struct kvm_vm *vm)
{
sparsebit_set_num(vm->vpages_valid,
0, (1ULL << (vm->va_bits - 1)) >> vm->page_shift);
sparsebit_set_num(vm->vpages_valid,
(~((1ULL << (vm->va_bits - 1)) - 1)) >> vm->page_shift,
(1ULL << (vm->va_bits - 1)) >> vm->page_shift);
}
struct kvm_vm *____vm_create(enum vm_guest_mode mode)
{
struct kvm_vm *vm;
......@@ -274,11 +283,7 @@ struct kvm_vm *____vm_create(enum vm_guest_mode mode)
/* Limit to VA-bit canonical virtual addresses. */
vm->vpages_valid = sparsebit_alloc();
sparsebit_set_num(vm->vpages_valid,
0, (1ULL << (vm->va_bits - 1)) >> vm->page_shift);
sparsebit_set_num(vm->vpages_valid,
(~((1ULL << (vm->va_bits - 1)) - 1)) >> vm->page_shift,
(1ULL << (vm->va_bits - 1)) >> vm->page_shift);
vm_vaddr_populate_bitmap(vm);
/* Limit physical addresses to PA-bits. */
vm->max_gfn = vm_compute_max_gfn(vm);
......
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