From 3920552846e881bafa9f9aad0bb1a6eef874d7fb Mon Sep 17 00:00:00 2001 From: Keqian Zhu Date: Thu, 17 Dec 2020 09:49:41 +0800 Subject: [PATCH] accel: kvm: Add aligment assert for kvm_log_clear_one_slot The parameters start and size are transfered from QEMU memory emulation layer. It can promise that they are TARGET_PAGE_SIZE aligned. However, KVM needs they are qemu_real_page_size aligned. Though no caller breaks this aligned requirement currently, we'd better add an explicit assert to avoid future breaking. Signed-off-by: Keqian Zhu Acked-by: Peter Xu Reviewed-by: Andrew Jones Message-Id: <20201217014941.22872-3-zhukeqian1@huawei.com> Signed-off-by: Paolo Bonzini --- accel/kvm/kvm-all.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index ffce83f1a7..f88a52393f 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -673,6 +673,10 @@ out: #define KVM_CLEAR_LOG_ALIGN (qemu_real_host_page_size << KVM_CLEAR_LOG_SHIFT) #define KVM_CLEAR_LOG_MASK (-KVM_CLEAR_LOG_ALIGN) +/* + * As the granule of kvm dirty log is qemu_real_host_page_size, + * @start and @size are expected and restricted to align to it. + */ static int kvm_log_clear_one_slot(KVMSlot *mem, int as_id, uint64_t start, uint64_t size) { @@ -682,6 +686,9 @@ static int kvm_log_clear_one_slot(KVMSlot *mem, int as_id, uint64_t start, unsigned long *bmap_clear = NULL, psize = qemu_real_host_page_size; int ret; + /* Make sure start and size are qemu_real_host_page_size aligned */ + assert(QEMU_IS_ALIGNED(start | size, psize)); + /* * We need to extend either the start or the size or both to * satisfy the KVM interface requirement. Firstly, do the start