[PATCH v3 3/5] KVM: riscv: selftests: Fix incorrect rounding in page_align()

Fuad Tabba
2026-01-06T09:24:30Z

The implementation of `page_align()` in `processor.c` calculates
alignment incorrectly for values that are already aligned. Specifically,
`(v + vm->page_size) & ~(vm->page_size - 1)` aligns to the *next* page
boundary even if `v` is already page-aligned, potentially wasting a page
of memory.

Fix the calculation to use standard alignment logic: `(v + vm->page_size
- 1) & ~(vm->page_size - 1)`.

Fixes: 3e06cdf10520 ("KVM: selftests: Add initial support for RISC-V 64-bit")
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
---
tools/testing/selftests/kvm/lib/riscv/processor.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c
index 2eac7d4b59e9..d5e8747b5e69 100644
--- a/tools/testing/selftests/kvm/lib/riscv/processor.c
+++ b/tools/testing/selftests/kvm/lib/riscv/processor.c
@@ -28,7 +28,7 @@ bool __vcpu_has_ext(struct kvm_vcpu *vcpu, uint64_t ext)

static uint64_t page_align(struct kvm_vm *vm, uint64_t v)
{
- return (v + vm->page_size) & ~(vm->page_size - 1);
+ return (v + vm->page_size - 1) & ~(vm->page_size - 1);
}

static uint64_t pte_addr(struct kvm_vm *vm, uint64_t entry)
--
2.52.0.351.gbe84eed79e-goog