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| author | Sean Christopherson <seanjc@google.com> | 2026-05-12 18:56:34 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2026-05-12 23:26:10 +0300 |
| commit | 87c810160ed738cd983e4a65ebe9709927c702c9 (patch) | |
| tree | c795494bb3d780a6d1b2be263d130ff019af9341 | |
| parent | 4a9ee4fc795389d6919d52a0cce490f9712e4f8c (diff) | |
| download | linux-87c810160ed738cd983e4a65ebe9709927c702c9.tar.xz | |
KVM: selftests: Ensure gmem file sizes are multiple of host page size
When creating a guest_memfd file and associated memslot to validate shared
guest memory, size the file+memslot to the maximum of the host or guest
page size. Attempting to allocate a single guest page will fail if the
host page size is greater than the guest page size, as KVM requires that
the size of memslots and guest_memfd files are a multiple of the host page
size.
For simplicity, verify the entire file can be shared between guest and host,
e.g. instead of trying to validate "partial" mappings.
Fixes: 42188667be38 ("KVM: selftests: Add guest_memfd testcase to fault-in on !mmap()'d memory")
Reported-by: Zenghui Yu <zenghui.yu@linux.dev>
Closes: https://lore.kernel.org/all/0064952b-048c-455d-ad89-e27e5cb82591@linux.dev
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260512155634.772602-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | tools/testing/selftests/kvm/guest_memfd_test.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing/selftests/kvm/guest_memfd_test.c index d6528c6f5e03..253e748c1d4a 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -510,7 +510,12 @@ static void test_guest_memfd_guest(void) "Default VM type should support INIT_SHARED, supported flags = 0x%x", vm_check_cap(vm, KVM_CAP_GUEST_MEMFD_FLAGS)); - size = vm->page_size; + /* + * Use the max of the host or guest page size for all operations, as + * KVM requires guest_memfd files and memslots to be sized to multiples + * of the host page size. + */ + size = max_t(size_t, vm->page_size, page_size); fd = vm_create_guest_memfd(vm, size, GUEST_MEMFD_FLAG_MMAP | GUEST_MEMFD_FLAG_INIT_SHARED); vm_set_user_memory_region2(vm, slot, KVM_MEM_GUEST_MEMFD, gpa, size, NULL, fd, 0); @@ -519,7 +524,7 @@ static void test_guest_memfd_guest(void) memset(mem, 0xaa, size); kvm_munmap(mem, size); - virt_pg_map(vm, gpa, gpa); + virt_map(vm, gpa, gpa, size / vm->page_size); vcpu_args_set(vcpu, 2, gpa, size); vcpu_run(vcpu); |