aboutsummaryrefslogtreecommitdiff
path: root/memory.h
diff options
context:
space:
mode:
authorAvi Kivity <avi@redhat.com>2011-12-08 15:00:18 +0200
committerAvi Kivity <avi@redhat.com>2011-12-20 14:14:07 +0200
commite2177955a899483b19bd54e547db3b61db95eaf7 (patch)
treec4aa673b055838f97f722c37f9c7323a6955c88f /memory.h
parent55043ba37ee4b080a4f4f77b0ff672be3cbf8825 (diff)
downloadqemu-e2177955a899483b19bd54e547db3b61db95eaf7.zip
qemu-e2177955a899483b19bd54e547db3b61db95eaf7.tar.gz
qemu-e2177955a899483b19bd54e547db3b61db95eaf7.tar.bz2
memory: introduce memory_region_find()
Given an address space (represented by the top-level memory region), returns the memory region that maps a given range. Useful for implementing DMA. The implementation is a simplistic binary search. Once we have a tree representation this can be optimized. Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'memory.h')
-rw-r--r--memory.h39
1 files changed, 39 insertions, 0 deletions
diff --git a/memory.h b/memory.h
index 87fb974..4d8f39a 100644
--- a/memory.h
+++ b/memory.h
@@ -148,6 +148,24 @@ struct MemoryRegionPortio {
#define PORTIO_END_OF_LIST() { }
+typedef struct MemoryRegionSection MemoryRegionSection;
+
+/**
+ * MemoryRegionSection: describes a fragment of a #MemoryRegion
+ *
+ * @mr: the region, or %NULL if empty
+ * @offset_within_region: the beginning of the section, relative to @mr's start
+ * @size: the size of the section; will not exceed @mr's boundaries
+ * @offset_within_address_space: the address of the first byte of the section
+ * relative to the region's address space
+ */
+struct MemoryRegionSection {
+ MemoryRegion *mr;
+ target_phys_addr_t offset_within_region;
+ uint64_t size;
+ target_phys_addr_t offset_within_address_space;
+};
+
/**
* memory_region_init: Initialize a memory region
*
@@ -569,6 +587,27 @@ void memory_region_set_alias_offset(MemoryRegion *mr,
target_phys_addr_t offset);
/**
+ * memory_region_find: locate a MemoryRegion in an address space
+ *
+ * Locates the first #MemoryRegion within an address space given by
+ * @address_space that overlaps the range given by @addr and @size.
+ *
+ * Returns a #MemoryRegionSection that describes a contiguous overlap.
+ * It will have the following characteristics:
+ * .@offset_within_address_space >= @addr
+ * .@offset_within_address_space + .@size <= @addr + @size
+ * .@size = 0 iff no overlap was found
+ * .@mr is non-%NULL iff an overlap was found
+ *
+ * @address_space: a top-level (i.e. parentless) region that contains
+ * the region to be found
+ * @addr: start of the area within @address_space to be searched
+ * @size: size of the area to be searched
+ */
+MemoryRegionSection memory_region_find(MemoryRegion *address_space,
+ target_phys_addr_t addr, uint64_t size);
+
+/**
* memory_region_transaction_begin: Start a transaction.
*
* During a transaction, changes will be accumulated and made visible