On Fri, 17 Jan 2020 17:45:16 +0000 Shameer Kolothum <shameerali.kolothum.th...@huawei.com> wrote:
> If ACPI blob length modifications happens after the initial > virt_acpi_build() call, and the changed blob length is within > the PAGE size boundary, then the revised size is not seen by > the firmware on Guest reboot. The is because in the > virt_acpi_build_update() -> acpi_ram_update() -> qemu_ram_resize() > path, qemu_ram_resize() uses used_length (ram_block size which is > aligned to PAGE size) and the "resize callback" to update the size > seen by firmware is not getting invoked. > > Hence make sure callback is called if the new size is different > from original requested size. > > Signed-off-by: Shameer Kolothum <shameerali.kolothum.th...@huawei.com> > --- > Please find the previous discussions on this issue here, > https://patchwork.kernel.org/patch/11174947/ > > But this one attempts a different solution to fix it by introducing > req_length var to RAMBlock struct. > looks fine to me, so Acked-by: Igor Mammedov <imamm...@redhat.com> CCing David who touches this area in his latest series for and might have an opinion on how it should be handled. > --- > exec.c | 36 +++++++++++++++++++++++------------- > include/exec/ram_addr.h | 5 +++-- > 2 files changed, 26 insertions(+), 15 deletions(-) > > diff --git a/exec.c b/exec.c > index d4b769d0d4..9ce33992f8 100644 > --- a/exec.c > +++ b/exec.c > @@ -2123,16 +2123,18 @@ static int memory_try_enable_merging(void *addr, > size_t len) > * resize callback to update device state and/or add assertions to detect > * misuse, if necessary. > */ > -int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp) > +int qemu_ram_resize(RAMBlock *block, ram_addr_t size, Error **errp) > { > - assert(block); > + ram_addr_t newsize; > > - newsize = HOST_PAGE_ALIGN(newsize); > + assert(block); > > - if (block->used_length == newsize) { > + if (block->req_length == size) { > return 0; > } > > + newsize = HOST_PAGE_ALIGN(size); > + > if (!(block->flags & RAM_RESIZEABLE)) { > error_setg_errno(errp, EINVAL, > "Length mismatch: %s: 0x" RAM_ADDR_FMT > @@ -2149,13 +2151,19 @@ int qemu_ram_resize(RAMBlock *block, ram_addr_t > newsize, Error **errp) > return -EINVAL; > } > > - cpu_physical_memory_clear_dirty_range(block->offset, block->used_length); > - block->used_length = newsize; > - cpu_physical_memory_set_dirty_range(block->offset, block->used_length, > - DIRTY_CLIENTS_ALL); > - memory_region_set_size(block->mr, newsize); > + block->req_length = size; > + > + if (newsize != block->used_length) { > + cpu_physical_memory_clear_dirty_range(block->offset, > + block->used_length); > + block->used_length = newsize; > + cpu_physical_memory_set_dirty_range(block->offset, > block->used_length, > + DIRTY_CLIENTS_ALL); > + memory_region_set_size(block->mr, newsize); > + } > + > if (block->resized) { > - block->resized(block->idstr, newsize, block->host); > + block->resized(block->idstr, block->req_length, block->host); > } > return 0; > } > @@ -2412,16 +2420,18 @@ RAMBlock *qemu_ram_alloc_internal(ram_addr_t size, > ram_addr_t max_size, > MemoryRegion *mr, Error **errp) > { > RAMBlock *new_block; > + ram_addr_t newsize; > Error *local_err = NULL; > > - size = HOST_PAGE_ALIGN(size); > + newsize = HOST_PAGE_ALIGN(size); > max_size = HOST_PAGE_ALIGN(max_size); > new_block = g_malloc0(sizeof(*new_block)); > new_block->mr = mr; > new_block->resized = resized; > - new_block->used_length = size; > + new_block->req_length = size; > + new_block->used_length = newsize; > new_block->max_length = max_size; > - assert(max_size >= size); > + assert(max_size >= newsize); > new_block->fd = -1; > new_block->page_size = qemu_real_host_page_size; > new_block->host = host; > diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h > index 5adebb0bc7..fd13082224 100644 > --- a/include/exec/ram_addr.h > +++ b/include/exec/ram_addr.h > @@ -31,8 +31,9 @@ struct RAMBlock { > uint8_t *host; > uint8_t *colo_cache; /* For colo, VM's ram cache */ > ram_addr_t offset; > - ram_addr_t used_length; > - ram_addr_t max_length; > + ram_addr_t req_length; /* Original requested size, used if > RAM_RESIZEABLE */ > + ram_addr_t used_length; /* aligned to qemu_host_page_size */ > + ram_addr_t max_length; /* aligned to qemu_host_page_size */ > void (*resized)(const char*, uint64_t length, void *host); > uint32_t flags; > /* Protected by iothread lock. */
