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memory: Export a helper to get intersection of a MemoryRegionSection with a given range

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Rename the helper to memory_region_section_intersect_range() to make it
more generic. Meanwhile, define the @end as Int128 and replace the
related operations with Int128_* format since the helper is exported as
a wider API.

Suggested-by: Alexey Kardashevskiy <aik@amd.com>
Reviewed-by: Alexey Kardashevskiy <aik@amd.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Link: https://lore.kernel.org/r/20250612082747.51539-2-chenyi.qiang@intel.com
Signed-off-by: Peter Xu <peterx@redhat.com>
This commit is contained in:
Chenyi Qiang 2025-06-12 16:27:42 +08:00 • committed by Peter Xu
parent 983899eab4
commit f47a672a72
2 changed files with 35 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

32
hw/virtio/virtio-mem.c
View file

@ -244,28 +244,6 @@ static int virtio_mem_for_each_plugged_range(VirtIOMEM *vmem, void *arg,
return ret;
}
/*
* Adjust the memory section to cover the intersection with the given range.
*
* Returns false if the intersection is empty, otherwise returns true.
*/
static bool virtio_mem_intersect_memory_section(MemoryRegionSection *s,
uint64_t offset, uint64_t size)
{
uint64_t start = MAX(s->offset_within_region, offset);
uint64_t end = MIN(s->offset_within_region + int128_get64(s->size),
offset + size);
if (end <= start) {
return false;
}
s->offset_within_address_space += start - s->offset_within_region;
s->offset_within_region = start;
s->size = int128_make64(end - start);
return true;
}
typedef int (*virtio_mem_section_cb)(MemoryRegionSection *s, void *arg);
static int virtio_mem_for_each_plugged_section(const VirtIOMEM *vmem,
@ -287,7 +265,7 @@ static int virtio_mem_for_each_plugged_section(const VirtIOMEM *vmem,
first_bit + 1) - 1;
size = (last_bit - first_bit + 1) * vmem->block_size;
if (!virtio_mem_intersect_memory_section(&tmp, offset, size)) {
if (!memory_region_section_intersect_range(&tmp, offset, size)) {
break;
}
ret = cb(&tmp, arg);
@ -319,7 +297,7 @@ static int virtio_mem_for_each_unplugged_section(const VirtIOMEM *vmem,
first_bit + 1) - 1;
size = (last_bit - first_bit + 1) * vmem->block_size;
if (!virtio_mem_intersect_memory_section(&tmp, offset, size)) {
if (!memory_region_section_intersect_range(&tmp, offset, size)) {
break;
}
ret = cb(&tmp, arg);
@ -355,7 +333,7 @@ static void virtio_mem_notify_unplug(VirtIOMEM *vmem, uint64_t offset,
QLIST_FOREACH(rdl, &vmem->rdl_list, next) {
MemoryRegionSection tmp = *rdl->section;
if (!virtio_mem_intersect_memory_section(&tmp, offset, size)) {
if (!memory_region_section_intersect_range(&tmp, offset, size)) {
continue;
}
rdl->notify_discard(rdl, &tmp);
@ -371,7 +349,7 @@ static int virtio_mem_notify_plug(VirtIOMEM *vmem, uint64_t offset,
QLIST_FOREACH(rdl, &vmem->rdl_list, next) {
MemoryRegionSection tmp = *rdl->section;
if (!virtio_mem_intersect_memory_section(&tmp, offset, size)) {
if (!memory_region_section_intersect_range(&tmp, offset, size)) {
continue;
}
ret = rdl->notify_populate(rdl, &tmp);
@ -388,7 +366,7 @@ static int virtio_mem_notify_plug(VirtIOMEM *vmem, uint64_t offset,
if (rdl2 == rdl) {
break;
}
if (!virtio_mem_intersect_memory_section(&tmp, offset, size)) {
if (!memory_region_section_intersect_range(&tmp, offset, size)) {
continue;
}
rdl2->notify_discard(rdl2, &tmp);

30
include/system/memory.h
View file

@ -1211,6 +1211,36 @@ MemoryRegionSection *memory_region_section_new_copy(MemoryRegionSection *s);
*/
void memory_region_section_free_copy(MemoryRegionSection *s);
/**
* memory_region_section_intersect_range: Adjust the memory section to cover
* the intersection with the given range.
*
* @s: the #MemoryRegionSection to be adjusted
* @offset: the offset of the given range in the memory region
* @size: the size of the given range
*
* Returns false if the intersection is empty, otherwise returns true.
*/
static inline bool memory_region_section_intersect_range(MemoryRegionSection *s,
uint64_t offset,
uint64_t size)
{
uint64_t start = MAX(s->offset_within_region, offset);
Int128 end = int128_min(int128_add(int128_make64(s->offset_within_region),
s->size),
int128_add(int128_make64(offset),
int128_make64(size)));
if (int128_le(end, int128_make64(start))) {
return false;
}
s->offset_within_address_space += start - s->offset_within_region;
s->offset_within_region = start;
s->size = int128_sub(end, int128_make64(start));
return true;
}
/**
* memory_region_init: Initialize a memory region
*