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Re: [Qemu-devel] [PATCH] memory: update coalesced_range on transaction_c
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH] memory: update coalesced_range on transaction_commit |
Date: |
Wed, 28 Nov 2018 11:03:53 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 |
On 28/11/18 10:17, Atsushi Nemoto wrote:
> The e1000 driver calls memory_region_add_coalescing but
> kvm_coalesce_mmio_region never been called for those regions.
>
> Update coalesced_range on memory_region_transaction_commit to fix this.
>
> It seems very old bug since memory region API
> was merged on commit 093bc2cd885e ("Hierarchical memory region API").
>
> Signed-off-by: Atsushi Nemoto <address@hidden>
> ---
> memory.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/memory.c b/memory.c
> index d14c6dec1d..f773b0be50 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -1021,6 +1021,8 @@ void memory_region_transaction_begin(void)
> ++memory_region_transaction_depth;
> }
>
> +static void memory_region_update_coalesced_range_as(MemoryRegion *mr,
> AddressSpace *as);
> +
> void memory_region_transaction_commit(void)
> {
> AddressSpace *as;
> @@ -1038,6 +1040,7 @@ void memory_region_transaction_commit(void)
> QTAILQ_FOREACH(as, &address_spaces, address_spaces_link) {
> address_space_set_flatview(as);
> address_space_update_ioeventfds(as);
> + memory_region_update_coalesced_range_as(NULL, as);
> }
> memory_region_update_pending = false;
> ioeventfd_update_pending = false;
> @@ -2142,7 +2145,7 @@ static void
> memory_region_update_coalesced_range_as(MemoryRegion *mr, AddressSpa
>
> view = address_space_get_flatview(as);
> FOR_EACH_FLAT_RANGE(fr, view) {
> - if (fr->mr == mr) {
> + if (fr->mr == mr || (!mr && !QTAILQ_EMPTY(&fr->mr->coalesced))) {
> section = (MemoryRegionSection) {
> .fv = view,
> .offset_within_address_space = int128_get64(fr->addr.start),
I'm worried that coalesced_io_del would be skipped when the region is
deleted. I think the right place to add the coalesced_io_{add,del}
calls is address_space_update_topology_pass.
Let me test an alternative fix and post it; thanks for the report in the
meanwhile!
Paolo
> @@ -2152,7 +2155,7 @@ static void
> memory_region_update_coalesced_range_as(MemoryRegion *mr, AddressSpa
> MEMORY_LISTENER_CALL(as, coalesced_io_del, Reverse, §ion,
> int128_get64(fr->addr.start),
> int128_get64(fr->addr.size));
> - QTAILQ_FOREACH(cmr, &mr->coalesced, link) {
> + QTAILQ_FOREACH(cmr, &fr->mr->coalesced, link) {
> tmp = addrrange_shift(cmr->addr,
> int128_sub(fr->addr.start,
>
> int128_make64(fr->offset_in_region)));
>