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kvm: factor out alignment of memory section

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Factor it out, so we can reuse it later.

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170911174933.20789-3-david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
David Hildenbrand 2017-09-11 19:49:29 +02:00 committed by Paolo Bonzini
parent 89de4b9138
commit 5ea69c2e36
1 changed files with 39 additions and 20 deletions
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59
accel/kvm/kvm-all.c
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@ -189,6 +189,36 @@ static KVMSlot *kvm_lookup_matching_slot(KVMMemoryListener *kml,
return NULL; return NULL;
} }
/*
* Calculate and align the start address and the size of the section.
* Return the size. If the size is 0, the aligned section is empty.
*/
static hwaddr kvm_align_section(MemoryRegionSection *section,
hwaddr *start)
{
hwaddr size = int128_get64(section->size);
hwaddr delta;
*start = section->offset_within_address_space;
/* kvm works in page size chunks, but the function may be called
with sub-page size and unaligned start address. Pad the start
address to next and truncate size to previous page boundary. */
delta = qemu_real_host_page_size - (*start & ~qemu_real_host_page_mask);
delta &= ~qemu_real_host_page_mask;
*start += delta;
if (delta > size) {
return 0;
}
size -= delta;
size &= qemu_real_host_page_mask;
if (*start & ~qemu_real_host_page_mask) {
return 0;
}
return size;
}
/* /*
* Find overlapping slot with lowest start address * Find overlapping slot with lowest start address
*/ */
@ -700,25 +730,8 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
int err; int err;
MemoryRegion *mr = section->mr; MemoryRegion *mr = section->mr;
bool writeable = !mr->readonly && !mr->rom_device; bool writeable = !mr->readonly && !mr->rom_device;
hwaddr start_addr = section->offset_within_address_space; hwaddr start_addr, size;
ram_addr_t size = int128_get64(section->size); void *ram;
void *ram = NULL;
unsigned delta;
/* kvm works in page size chunks, but the function may be called
with sub-page size and unaligned start address. Pad the start
address to next and truncate size to previous page boundary. */
delta = qemu_real_host_page_size - (start_addr & ~qemu_real_host_page_mask);
delta &= ~qemu_real_host_page_mask;
if (delta > size) {
return;
}
start_addr += delta;
size -= delta;
size &= qemu_real_host_page_mask;
if (!size || (start_addr & ~qemu_real_host_page_mask)) {
return;
}
if (!memory_region_is_ram(mr)) { if (!memory_region_is_ram(mr)) {
if (writeable || !kvm_readonly_mem_allowed) { if (writeable || !kvm_readonly_mem_allowed) {
@ -730,7 +743,13 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
} }
} }
ram = memory_region_get_ram_ptr(mr) + section->offset_within_region + delta; size = kvm_align_section(section, &start_addr);
if (!size) {
return;
}
ram = memory_region_get_ram_ptr(mr) + section->offset_within_region +
(section->offset_within_address_space - start_addr);
while (1) { while (1) {
mem = kvm_lookup_overlapping_slot(kml, start_addr, start_addr + size); mem = kvm_lookup_overlapping_slot(kml, start_addr, start_addr + size);