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81607729 FE |
1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
2 | From: Fiona Ebner <f.ebner@proxmox.com> | |
3 | Date: Thu, 24 Aug 2023 11:22:21 +0200 | |
4 | Subject: [PATCH] hw/ide: reset: cancel async DMA operation before reseting | |
5 | state | |
6 | ||
7 | If there is a pending DMA operation during ide_bus_reset(), the fact | |
8 | that the IDEstate is already reset before the operation is canceled | |
9 | can be problematic. In particular, ide_dma_cb() might be called and | |
10 | then use the reset IDEstate which contains the signature after the | |
11 | reset. When used to construct the IO operation this leads to | |
12 | ide_get_sector() returning 0 and nsector being 1. This is particularly | |
13 | bad, because a write command will thus destroy the first sector which | |
14 | often contains a partition table or similar. | |
15 | ||
16 | Traces showing the unsolicited write happening with IDEstate | |
17 | 0x5595af6949d0 being used after reset: | |
18 | ||
19 | > ahci_port_write ahci(0x5595af6923f0)[0]: port write [reg:PxSCTL] @ 0x2c: 0x00000300 | |
20 | > ahci_reset_port ahci(0x5595af6923f0)[0]: reset port | |
21 | > ide_reset IDEstate 0x5595af6949d0 | |
22 | > ide_reset IDEstate 0x5595af694da8 | |
23 | > ide_bus_reset_aio aio_cancel | |
24 | > dma_aio_cancel dbs=0x7f64600089a0 | |
25 | > dma_blk_cb dbs=0x7f64600089a0 ret=0 | |
26 | > dma_complete dbs=0x7f64600089a0 ret=0 cb=0x5595acd40b30 | |
27 | > ahci_populate_sglist ahci(0x5595af6923f0)[0] | |
28 | > ahci_dma_prepare_buf ahci(0x5595af6923f0)[0]: prepare buf limit=512 prepared=512 | |
29 | > ide_dma_cb IDEState 0x5595af6949d0; sector_num=0 n=1 cmd=DMA WRITE | |
30 | > dma_blk_io dbs=0x7f6420802010 bs=0x5595ae2c6c30 offset=0 to_dev=1 | |
31 | > dma_blk_cb dbs=0x7f6420802010 ret=0 | |
32 | ||
33 | > (gdb) p *qiov | |
34 | > $11 = {iov = 0x7f647c76d840, niov = 1, {{nalloc = 1, local_iov = {iov_base = 0x0, | |
35 | > iov_len = 512}}, {__pad = "\001\000\000\000\000\000\000\000\000\000\000", | |
36 | > size = 512}}} | |
37 | > (gdb) bt | |
38 | > #0 blk_aio_pwritev (blk=0x5595ae2c6c30, offset=0, qiov=0x7f6420802070, flags=0, | |
39 | > cb=0x5595ace6f0b0 <dma_blk_cb>, opaque=0x7f6420802010) | |
40 | > at ../block/block-backend.c:1682 | |
41 | > #1 0x00005595ace6f185 in dma_blk_cb (opaque=0x7f6420802010, ret=<optimized out>) | |
42 | > at ../softmmu/dma-helpers.c:179 | |
43 | > #2 0x00005595ace6f778 in dma_blk_io (ctx=0x5595ae0609f0, | |
44 | > sg=sg@entry=0x5595af694d00, offset=offset@entry=0, align=align@entry=512, | |
45 | > io_func=io_func@entry=0x5595ace6ee30 <dma_blk_write_io_func>, | |
46 | > io_func_opaque=io_func_opaque@entry=0x5595ae2c6c30, | |
47 | > cb=0x5595acd40b30 <ide_dma_cb>, opaque=0x5595af6949d0, | |
48 | > dir=DMA_DIRECTION_TO_DEVICE) at ../softmmu/dma-helpers.c:244 | |
49 | > #3 0x00005595ace6f90a in dma_blk_write (blk=0x5595ae2c6c30, | |
50 | > sg=sg@entry=0x5595af694d00, offset=offset@entry=0, align=align@entry=512, | |
51 | > cb=cb@entry=0x5595acd40b30 <ide_dma_cb>, opaque=opaque@entry=0x5595af6949d0) | |
52 | > at ../softmmu/dma-helpers.c:280 | |
53 | > #4 0x00005595acd40e18 in ide_dma_cb (opaque=0x5595af6949d0, ret=<optimized out>) | |
54 | > at ../hw/ide/core.c:953 | |
55 | > #5 0x00005595ace6f319 in dma_complete (ret=0, dbs=0x7f64600089a0) | |
56 | > at ../softmmu/dma-helpers.c:107 | |
57 | > #6 dma_blk_cb (opaque=0x7f64600089a0, ret=0) at ../softmmu/dma-helpers.c:127 | |
58 | > #7 0x00005595ad12227d in blk_aio_complete (acb=0x7f6460005b10) | |
59 | > at ../block/block-backend.c:1527 | |
60 | > #8 blk_aio_complete (acb=0x7f6460005b10) at ../block/block-backend.c:1524 | |
61 | > #9 blk_aio_write_entry (opaque=0x7f6460005b10) at ../block/block-backend.c:1594 | |
62 | > #10 0x00005595ad258cfb in coroutine_trampoline (i0=<optimized out>, | |
63 | > i1=<optimized out>) at ../util/coroutine-ucontext.c:177 | |
64 | ||
65 | Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> | |
66 | --- | |
67 | hw/ide/core.c | 14 +++++++------- | |
68 | 1 file changed, 7 insertions(+), 7 deletions(-) | |
69 | ||
70 | diff --git a/hw/ide/core.c b/hw/ide/core.c | |
10e10933 | 71 | index 6a74afe564..289347af58 100644 |
81607729 FE |
72 | --- a/hw/ide/core.c |
73 | +++ b/hw/ide/core.c | |
10e10933 | 74 | @@ -2515,19 +2515,19 @@ static void ide_dummy_transfer_stop(IDEState *s) |
81607729 FE |
75 | |
76 | void ide_bus_reset(IDEBus *bus) | |
77 | { | |
78 | - bus->unit = 0; | |
79 | - bus->cmd = 0; | |
80 | - ide_reset(&bus->ifs[0]); | |
81 | - ide_reset(&bus->ifs[1]); | |
82 | - ide_clear_hob(bus); | |
83 | - | |
84 | - /* pending async DMA */ | |
85 | + /* pending async DMA - needs the IDEState before it is reset */ | |
86 | if (bus->dma->aiocb) { | |
87 | trace_ide_bus_reset_aio(); | |
88 | blk_aio_cancel(bus->dma->aiocb); | |
89 | bus->dma->aiocb = NULL; | |
90 | } | |
91 | ||
92 | + bus->unit = 0; | |
93 | + bus->cmd = 0; | |
94 | + ide_reset(&bus->ifs[0]); | |
95 | + ide_reset(&bus->ifs[1]); | |
96 | + ide_clear_hob(bus); | |
97 | + | |
98 | /* reset dma provider too */ | |
99 | if (bus->dma->ops->reset) { | |
100 | bus->dma->ops->reset(bus->dma); |