Re: [Qemu-devel] [PATCH v4 3/3] tests: in IDE and AHCI tests perform DMA write before flushing

[John Snow <jsnow@redhat.com>]

On 06/27/2016 10:47 AM, Denis V. Lunev wrote:
> From: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
> 
> Due to changes in flush behaviour clean disks stopped generating
> flush_to_disk events and IDE and AHCI tests that test flush commands
> started to fail.
> 
> This change adds additional DMA writes to affected tests before sending
> flush commands so that bdrv_flush actually generates flush_to_disk event.
> 
> Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> CC: Kevin Wolf <kwolf@redhat.com>
> CC: Max Reitz <mreitz@redhat.com>
> CC: Stefan Hajnoczi <stefanha@redhat.com>
> CC: Fam Zheng <famz@redhat.com>
> CC: John Snow <jsnow@redhat.com>
> ---
>  tests/ahci-test.c | 34 ++++++++++++++++++++++++++++++++--
>  tests/ide-test.c  | 43 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 75 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/ahci-test.c b/tests/ahci-test.c
> index 57dc44c..d707714 100644
> --- a/tests/ahci-test.c
> +++ b/tests/ahci-test.c
> @@ -1063,11 +1063,34 @@ static void test_dma_fragmented(void)
>      g_free(tx);
>  }
>  
> +/*
> + * Write sector 0 with random data to make AHCI storage dirty
> + * Needed for flush tests so that flushes actually go though the block layer
> + */
> +static void make_dirty(AHCIQState* ahci, uint8_t port)
> +{
> +    uint64_t ptr;
> +    unsigned bufsize = 512;
> +
> +    ptr = ahci_alloc(ahci, bufsize);
> +    g_assert(ptr);
> +
> +    ahci_guest_io(ahci, port, CMD_WRITE_DMA, ptr, bufsize, 0);
> +    ahci_free(ahci, ptr);
> +}
> +
>  static void test_flush(void)
>  {
>      AHCIQState *ahci;
> +    uint8_t port;
>  
>      ahci = ahci_boot_and_enable(NULL);
> +
> +    port = ahci_port_select(ahci);
> +    ahci_port_clear(ahci, port);
> +
> +    make_dirty(ahci, port);
> +
>      ahci_test_flush(ahci);
>      ahci_shutdown(ahci);
>  }
> @@ -1087,10 +1110,13 @@ static void test_flush_retry(void)
>                                  debug_path,
>                                  tmp_path, imgfmt);
>  
> -    /* Issue Flush Command and wait for error */
>      port = ahci_port_select(ahci);
>      ahci_port_clear(ahci, port);
>  
> +    /* Issue write so that flush actually goes to disk */
> +    make_dirty(ahci, port);
> +
> +    /* Issue Flush Command and wait for error */
>      cmd = ahci_guest_io_halt(ahci, port, CMD_FLUSH_CACHE, 0, 0, 0);
>      ahci_guest_io_resume(ahci, cmd);
>  
> @@ -1343,9 +1369,13 @@ static void test_flush_migrate(void)
>  
>      set_context(src->parent);
>  
> -    /* Issue Flush Command */
>      px = ahci_port_select(src);
>      ahci_port_clear(src, px);
> +
> +    /* Dirty device so that flush reaches disk */
> +    make_dirty(src, px);
> +
> +    /* Issue Flush Command */
>      cmd = ahci_command_create(CMD_FLUSH_CACHE);
>      ahci_command_commit(src, cmd, px);
>      ahci_command_issue_async(src, cmd);
> diff --git a/tests/ide-test.c b/tests/ide-test.c
> index fed1b2e..8466d0f 100644
> --- a/tests/ide-test.c
> +++ b/tests/ide-test.c
> @@ -499,6 +499,39 @@ static void test_identify(void)
>      ide_test_quit();
>  }
>  
> +/*
> + * Write sector 0 with random data to make IDE storage dirty
> + * Needed for flush tests so that flushes actually go though the block layer
> + */
> +static void make_dirty(uint8_t device)
> +{
> +    uint8_t status;
> +    size_t len = 512;
> +    uintptr_t guest_buf;
> +    void* buf;
> +
> +    guest_buf = guest_alloc(guest_malloc, len);
> +    buf = g_malloc(len);
> +    g_assert(guest_buf);
> +    g_assert(buf);
> +
> +    memwrite(guest_buf, buf, len);
> +
> +    PrdtEntry prdt[] = {
> +        {
> +            .addr = cpu_to_le32(guest_buf),
> +            .size = cpu_to_le32(len | PRDT_EOT),
> +        },
> +    };
> +
> +    status = send_dma_request(CMD_WRITE_DMA, 0, 1, prdt,
> +                              ARRAY_SIZE(prdt), NULL);
> +    g_assert_cmphex(status, ==, BM_STS_INTR);
> +    assert_bit_clear(inb(IDE_BASE + reg_status), DF | ERR);
> +
> +    g_free(buf);
> +}
> +
>  static void test_flush(void)
>  {
>      uint8_t data;
> @@ -507,6 +540,11 @@ static void test_flush(void)
>          "-drive file=blkdebug::%s,if=ide,cache=writeback,format=raw",
>          tmp_path);
>  
> +    qtest_irq_intercept_in(global_qtest, "ioapic");
> +
> +    /* Dirty media so that CMD_FLUSH_CACHE will actually go to disk */
> +    make_dirty(0);
> +
>      /* Delay the completion of the flush request until we explicitly do it */
>      g_free(hmp("qemu-io ide0-hd0 \"break flush_to_os A\""));
>  
> @@ -549,6 +587,11 @@ static void test_retry_flush(const char *machine)
>          "rerror=stop,werror=stop",
>          debug_path, tmp_path);
>  
> +    qtest_irq_intercept_in(global_qtest, "ioapic");
> +
> +    /* Dirty media so that CMD_FLUSH_CACHE will actually go to disk */
> +    make_dirty(0);
> +
>      /* FLUSH CACHE command on device 0*/
>      outb(IDE_BASE + reg_device, 0);
>      outb(IDE_BASE + reg_command, CMD_FLUSH_CACHE);
> 

Reviewed-by: John Snow <jsnow@redhat.com>

However, the patch-set needs to be re-ordered as 3-1-2. Intermediate
patch commits cannot have failing tests.