Re: [Qemu-devel] [PATCH v6 18/29] ivshmem-test: Drop dependence on global_qtest

[Thomas Huth <thuth@redhat.com>]

On 01.09.2017 20:03, Eric Blake wrote:
> Managing parallel connections to two different monitors via
> the implicit global_qtest makes it hard to copy-and-paste code
> to tests that are not aware of the implicit state.  Since we
> have already fixed qpci to avoid global_qtest, we can now
> simplify by not using global_qtest anywhere in ivshmem-test.
> 
> We can assert that the conversion is correct by checking that
> global_qtest remains NULL throughout the test (a later patch
> that changes global_qtest to not be a public global variable
> will drop the assertions).
> 
> Signed-off-by: Eric Blake <eblake@redhat.com>
> ---
>  tests/ivshmem-test.c | 18 ++----------------
>  1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/tests/ivshmem-test.c b/tests/ivshmem-test.c
> index 37763425ee..b9e0f573f6 100644
> --- a/tests/ivshmem-test.c
> +++ b/tests/ivshmem-test.c
> @@ -71,13 +71,10 @@ static const char* reg2str(enum Reg reg) {
>  static inline unsigned in_reg(IVState *s, enum Reg reg)
>  {
>      const char *name = reg2str(reg);
> -    QTestState *qtest = global_qtest;
>      unsigned res;
> 
> -    global_qtest = s->qs->qts;
>      res = qpci_io_readl(s->dev, s->reg_bar, reg);
>      g_test_message("*%s -> %x\n", name, res);
> -    global_qtest = qtest;
> 
>      return res;
>  }
> @@ -85,35 +82,25 @@ static inline unsigned in_reg(IVState *s, enum Reg reg)
>  static inline void out_reg(IVState *s, enum Reg reg, unsigned v)
>  {
>      const char *name = reg2str(reg);
> -    QTestState *qtest = global_qtest;
> 
> -    global_qtest = s->qs->qts;
>      g_test_message("%x -> *%s\n", v, name);
>      qpci_io_writel(s->dev, s->reg_bar, reg, v);
> -    global_qtest = qtest;
>  }
> 
>  static inline void read_mem(IVState *s, uint64_t off, void *buf, size_t len)
>  {
> -    QTestState *qtest = global_qtest;
> -
> -    global_qtest = s->qs->qts;
>      qpci_memread(s->dev, s->mem_bar, off, buf, len);
> -    global_qtest = qtest;
>  }
> 
>  static inline void write_mem(IVState *s, uint64_t off,
>                               const void *buf, size_t len)
>  {
> -    QTestState *qtest = global_qtest;
> -
> -    global_qtest = s->qs->qts;
>      qpci_memwrite(s->dev, s->mem_bar, off, buf, len);
> -    global_qtest = qtest;
>  }
> 
>  static void cleanup_vm(IVState *s)
>  {
> +    assert(!global_qtest);
>      g_free(s->dev);
>      qtest_shutdown(s->qs);
>  }
> @@ -131,6 +118,7 @@ static void setup_vm_cmd(IVState *s, const char *cmd, bool msix)
>          g_printerr("ivshmem-test tests are only available on x86 or ppc64\n");
>          exit(EXIT_FAILURE);
>      }
> +    global_qtest = NULL;
>      s->dev = get_device(s->qs->pcibus);
> 
>      s->reg_bar = qpci_iomap(s->dev, 0, &barsize);
> @@ -353,7 +341,6 @@ static void test_ivshmem_server(bool msi)
>      g_assert_cmpint(vm1, !=, vm2);
> 
>      /* check number of MSI-X vectors */
> -    global_qtest = s1->qs->qts;
>      if (msi) {
>          ret = qpci_msix_table_size(s1->dev);
>          g_assert_cmpuint(ret, ==, nvectors);
> @@ -376,7 +363,6 @@ static void test_ivshmem_server(bool msi)
>      g_assert_cmpuint(ret, !=, 0);
> 
>      /* ping vm1 -> vm2 on vector 1 */
> -    global_qtest = s2->qs->qts;
>      if (msi) {
>          ret = qpci_msix_pending(s2->dev, 1);
>          g_assert_cmpuint(ret, ==, 0);
> 

OMG, now I see why you want to get rid of this global_test stuff ...
that was really ugly!

Reviewed-by: Thomas Huth <thuth@redhat.com>