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 <zhukeqian1@huawei.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-Id: <20201217014941.22872-3-zhukeqian1@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Keqian Zhu 2020-12-17 09:49:41 +08:00 committed by Paolo Bonzini
parent e0a8f99355
commit 3920552846

View File

@ -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