Commit 5ea69c2e authored by David Hildenbrand's avatar David Hildenbrand Committed by Paolo Bonzini
Browse files

kvm: factor out alignment of memory section 



Factor it out, so we can reuse it later.

Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Message-Id: <20170911174933.20789-3-david@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 89de4b91

accel/kvm/kvm-all.c

+39 −20
Original line number Diff line number Diff line
@@ -189,6 +189,36 @@ static KVMSlot *kvm_lookup_matching_slot(KVMMemoryListener *kml, 
    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

 */
@@ -700,25 +730,8 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, 
    int err;

    MemoryRegion *mr = section->mr;

    bool writeable = !mr->readonly && !mr->rom_device;

    hwaddr start_addr = section->offset_within_address_space;

    ram_addr_t size = int128_get64(section->size);

    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;

    }

    hwaddr start_addr, size;

    void *ram;



    if (!memory_region_is_ram(mr)) {

        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) {

        mem = kvm_lookup_overlapping_slot(kml, start_addr, start_addr + size);