diff options
Diffstat (limited to 'hw/vhost.c')
| -rw-r--r-- | hw/vhost.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/hw/vhost.c b/hw/vhost.c index 257e3dd685..80f771e448 100644 --- a/hw/vhost.c +++ b/hw/vhost.c @@ -297,6 +297,45 @@ static int vhost_verify_ring_mappings(struct vhost_dev *dev, return 0; } +static struct vhost_memory_region *vhost_dev_find_reg(struct vhost_dev *dev, + uint64_t start_addr, + uint64_t size) +{ + int i, n = dev->mem->nregions; + for (i = 0; i < n; ++i) { + struct vhost_memory_region *reg = dev->mem->regions + i; + if (ranges_overlap(reg->guest_phys_addr, reg->memory_size, + start_addr, size)) { + return reg; + } + } + return NULL; +} + +static bool vhost_dev_cmp_memory(struct vhost_dev *dev, + uint64_t start_addr, + uint64_t size, + uint64_t uaddr) +{ + struct vhost_memory_region *reg = vhost_dev_find_reg(dev, start_addr, size); + uint64_t reglast; + uint64_t memlast; + + if (!reg) { + return true; + } + + reglast = range_get_last(reg->guest_phys_addr, reg->memory_size); + memlast = range_get_last(start_addr, size); + + /* Need to extend region? */ + if (start_addr < reg->guest_phys_addr || memlast > reglast) { + return true; + } + /* userspace_addr changed? */ + return uaddr != reg->userspace_addr + start_addr - reg->guest_phys_addr; +} + static void vhost_client_set_memory(CPUPhysMemoryClient *client, target_phys_addr_t start_addr, ram_addr_t size, @@ -309,6 +348,7 @@ static void vhost_client_set_memory(CPUPhysMemoryClient *client, (dev->mem->nregions + 1) * sizeof dev->mem->regions[0]; uint64_t log_size; int r; + dev->mem = qemu_realloc(dev->mem, s); if (log_dirty) { @@ -317,6 +357,20 @@ static void vhost_client_set_memory(CPUPhysMemoryClient *client, assert(size); + /* Optimize no-change case. At least cirrus_vga does this a lot at this time. */ + if (flags == IO_MEM_RAM) { + if (!vhost_dev_cmp_memory(dev, start_addr, size, + (uintptr_t)qemu_get_ram_ptr(phys_offset))) { + /* Region exists with same address. Nothing to do. */ + return; + } + } else { + if (!vhost_dev_find_reg(dev, start_addr, size)) { + /* Removing region that we don't access. Nothing to do. */ + return; + } + } + vhost_dev_unassign_memory(dev, start_addr, size); if (flags == IO_MEM_RAM) { /* Add given mapping, merging adjacent regions if any */ |