From 76d58e0f07ec203bbdfcaabd9a9fc10a5a3ed5ea Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 17 Apr 2019 15:28:44 +0200 Subject: KVM: fix KVM_CLEAR_DIRTY_LOG for memory slots of unaligned size If a memory slot's size is not a multiple of 64 pages (256K), then the KVM_CLEAR_DIRTY_LOG API is unusable: clearing the final 64 pages either requires the requested page range to go beyond memslot->npages, or requires log->num_pages to be unaligned, and kvm_clear_dirty_log_protect requires log->num_pages to be both in range and aligned. To allow this case, allow log->num_pages not to be a multiple of 64 if it ends exactly on the last page of the slot. Reported-by: Peter Xu Fixes: 98938aa8edd6 ("KVM: validate userspace input in kvm_clear_dirty_log_protect()", 2019-01-02) Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/dirty_log_test.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'tools/testing/selftests/kvm/dirty_log_test.c') diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c index 4715cfba20dc..93f99c6b7d79 100644 --- a/tools/testing/selftests/kvm/dirty_log_test.c +++ b/tools/testing/selftests/kvm/dirty_log_test.c @@ -288,8 +288,11 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations, #endif max_gfn = (1ul << (guest_pa_bits - guest_page_shift)) - 1; guest_page_size = (1ul << guest_page_shift); - /* 1G of guest page sized pages */ - guest_num_pages = (1ul << (30 - guest_page_shift)); + /* + * A little more than 1G of guest page sized pages. Cover the + * case where the size is not aligned to 64 pages. + */ + guest_num_pages = (1ul << (30 - guest_page_shift)) + 3; host_page_size = getpagesize(); host_num_pages = (guest_num_pages * guest_page_size) / host_page_size + !!((guest_num_pages * guest_page_size) % host_page_size); @@ -359,7 +362,7 @@ static void run_test(enum vm_guest_mode mode, unsigned long iterations, kvm_vm_get_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap); #ifdef USE_CLEAR_DIRTY_LOG kvm_vm_clear_dirty_log(vm, TEST_MEM_SLOT_INDEX, bmap, 0, - DIV_ROUND_UP(host_num_pages, 64) * 64); + host_num_pages); #endif vm_dirty_log_verify(bmap); iteration++; -- cgit v1.2.3-59-g8ed1b