On Wed, Dec 07, 2022, Oliver Upton wrote:
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c index 316de70db91d..5972a23b2765 100644 --- a/tools/testing/selftests/kvm/lib/aarch64/processor.c +++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c @@ -541,3 +541,13 @@ void kvm_selftest_arch_init(void) */ guest_modes_append_default(); }
+void vm_vaddr_populate_bitmap(struct kvm_vm *vm)
Add "arch" so that it's obvious this can be overidden? The "__weak" conveys that for the implementation, but not for the call site. E.g. vm_arch_vaddr_populate_bitmap().
Actually, IIUC, the issue is that the high half isn't mapped (probably the wrong terminology). I.e. the calculation for the low half stays the same, and the high half just goes away.
+{
- /*
* 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);+} diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index e9607eb089be..c88c3ace16d2 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -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);
Any objection to fixing up the formatting? Actually, we can do more than just fix the indentation, e.g. the number of bits is identical, and documenting that this does a high/low split would be helpful.
Together, what about? The #ifdef is a bit gross, especially around "hi_start", but it's less duplicate code. And IMO, having things bundled in the same place makes it a lot easier for newbies (to arm64 or kernel coding in general) to understand what's going on and why arm64 is different.
--- tools/testing/selftests/kvm/lib/kvm_util.c | 23 +++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index e9607eb089be..d6f2c17e3d40 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -186,6 +186,23 @@ 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?");
+static void vm_vaddr_populate_bitmap(struct kvm_vm *vm) +{ + /* + * All architectures supports splitting the virtual address space into + * a high and a low half. Populate both halves, except for arm64 which + * currently uses only TTBR0_EL1 (arbitrary selftests "logic"), i.e. + * only has a valid low half. + */ + sparsebit_num_t nr_va_bits = (1ULL << (vm->va_bits - 1)) >> vm->page_shift; +#ifndef __aarch64__ + sparsebit_num_t hi_start = (~((1ULL << (vm->va_bits - 1)) - 1)) >> vm->page_shift + + sparsebit_set_num(vm->vpages_valid, hi_start, nr_bits); +#endif + sparsebit_set_num(vm->vpages_valid, 0, nr_va_bits); +} + struct kvm_vm *____vm_create(enum vm_guest_mode mode) { struct kvm_vm *vm; @@ -274,11 +291,7 @@ 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);
base-commit: 35aecc3289eebf193fd70a067ea448ae2f0bb9b9