Re: [RFC PATCH 2/2] tests/qtest: Enable spapr dma with linear iommu map

[Fabiano Rosas <farosas@suse.de>]

Nicholas Piggin <npiggin@gmail.com> writes:

> qtests spapr dma was broken because the iommu was not set up.
>
> spapr requires hypercalls to set up the iommu (TCE tables), but
> there is no support for that or a side-channel to the iommu in
> qtests at the moment, so add a quick workaround in QEMU to have
> the spapr iommu provide a linear map to memory when running
> qtests.

That's fine.

But what would it take to add support? Add another callback such as
qtest_rtas_call() to handle hcalls and call H_PUT_TCE from the test? Or
is there some other complication?

>
> The buggy msix checks can all be removed since the tests all work
> now.
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>  tests/qtest/libqos/pci.h             |  4 ----
>  hw/ppc/spapr_iommu.c                 |  9 ++++++++-
>  tests/qtest/e1000e-test.c            | 23 +++--------------------
>  tests/qtest/igb-test.c               | 21 ---------------------
>  tests/qtest/libqos/generic-pcihost.c |  1 -
>  tests/qtest/libqos/pci-pc.c          |  3 ---
>  tests/qtest/libqos/pci-spapr.c       |  7 ++++---
>  tests/qtest/libqos/pci.c             | 14 --------------
>  tests/qtest/vhost-user-blk-test.c    |  6 ------
>  tests/qtest/virtio-blk-test.c        | 12 ------------
>  10 files changed, 15 insertions(+), 85 deletions(-)
>

...

> @@ -173,13 +159,10 @@ static void test_e1000e_multiple_transfers(void *obj, void *data,
>  
>      QE1000E_PCI *e1000e = obj;
>      QE1000E *d = &e1000e->e1000e;
> -    QOSGraphObject *e_object = obj;
> -    QPCIDevice *dev = e_object->get_driver(e_object, "pci-device");
>  
> -    /* FIXME: add spapr support */
> -    if (qpci_check_buggy_msi(dev)) {
> -        return;
> -    }
> +    /* Use EITR for one irq and disable it for the other, for testing */
> +    e1000e_macreg_write(d, E1000_EITR + E1000E_RX0_MSG_ID * 4, 500);
> +    e1000e_macreg_write(d, E1000_EITR + E1000E_TX0_MSG_ID * 4, 0);

What's this about?

>  
>      for (i = 0; i < iterations; i++) {
>          e1000e_send_verify(d, data, alloc);
> diff --git a/tests/qtest/igb-test.c b/tests/qtest/igb-test.c
> index 3d397ea6973..1b3b5aa6c76 100644
> --- a/tests/qtest/igb-test.c
> +++ b/tests/qtest/igb-test.c
> @@ -142,13 +142,6 @@ static void test_igb_tx(void *obj, void *data, QGuestAllocator * alloc)
>  {
>      QE1000E_PCI *e1000e = obj;
>      QE1000E *d = &e1000e->e1000e;
> -    QOSGraphObject *e_object = obj;
> -    QPCIDevice *dev = e_object->get_driver(e_object, "pci-device");
> -
> -    /* FIXME: add spapr support */
> -    if (qpci_check_buggy_msi(dev)) {
> -        return;
> -    }
>  
>      igb_send_verify(d, data, alloc);
>  }
> @@ -157,13 +150,6 @@ static void test_igb_rx(void *obj, void *data, QGuestAllocator * alloc)
>  {
>      QE1000E_PCI *e1000e = obj;
>      QE1000E *d = &e1000e->e1000e;
> -    QOSGraphObject *e_object = obj;
> -    QPCIDevice *dev = e_object->get_driver(e_object, "pci-device");
> -
> -    /* FIXME: add spapr support */
> -    if (qpci_check_buggy_msi(dev)) {
> -        return;
> -    }
>  
>      igb_receive_verify(d, data, alloc);
>  }
> @@ -176,13 +162,6 @@ static void test_igb_multiple_transfers(void *obj, void *data,
>  
>      QE1000E_PCI *e1000e = obj;
>      QE1000E *d = &e1000e->e1000e;
> -    QOSGraphObject *e_object = obj;
> -    QPCIDevice *dev = e_object->get_driver(e_object, "pci-device");
> -
> -    /* FIXME: add spapr support */
> -    if (qpci_check_buggy_msi(dev)) {
> -        return;
> -    }
>  
>      for (i = 0; i < iterations; i++) {
>          igb_send_verify(d, data, alloc);
> diff --git a/tests/qtest/libqos/generic-pcihost.c b/tests/qtest/libqos/generic-pcihost.c
> index 4bbeb5ff508..568897e0ecc 100644
> --- a/tests/qtest/libqos/generic-pcihost.c
> +++ b/tests/qtest/libqos/generic-pcihost.c
> @@ -182,7 +182,6 @@ void qpci_init_generic(QGenericPCIBus *qpci, QTestState *qts,
>  
>      qpci->gpex_pio_base = 0x3eff0000;
>      qpci->bus.not_hotpluggable = !hotpluggable;
> -    qpci->bus.has_buggy_msi = false;
>  
>      qpci->bus.pio_readb = qpci_generic_pio_readb;
>      qpci->bus.pio_readw = qpci_generic_pio_readw;
> diff --git a/tests/qtest/libqos/pci-pc.c b/tests/qtest/libqos/pci-pc.c
> index 147009f4f44..8b79d858bd5 100644
> --- a/tests/qtest/libqos/pci-pc.c
> +++ b/tests/qtest/libqos/pci-pc.c
> @@ -124,9 +124,6 @@ void qpci_init_pc(QPCIBusPC *qpci, QTestState *qts, QGuestAllocator *alloc)
>  {
>      assert(qts);
>  
> -    /* tests can use pci-bus */
> -    qpci->bus.has_buggy_msi = false;
> -
>      qpci->bus.pio_readb = qpci_pc_pio_readb;
>      qpci->bus.pio_readw = qpci_pc_pio_readw;
>      qpci->bus.pio_readl = qpci_pc_pio_readl;
> diff --git a/tests/qtest/libqos/pci-spapr.c b/tests/qtest/libqos/pci-spapr.c
> index 0f1023e4a73..dfa2087a599 100644
> --- a/tests/qtest/libqos/pci-spapr.c
> +++ b/tests/qtest/libqos/pci-spapr.c
> @@ -20,6 +20,10 @@
>   * PCI devices are always little-endian
>   * SPAPR by default is big-endian
>   * so PCI accessors need to swap data endianness
> + *
> + * The spapr iommu model has a qtest_enabled() check that short-cuts
> + * the TCE table and provides a linear map for DMA, since qtests does
> + * not have a way to make hcalls to set up the TCE table.
>   */
>  
>  static uint8_t qpci_spapr_pio_readb(QPCIBus *bus, uint32_t addr)
> @@ -155,9 +159,6 @@ void qpci_init_spapr(QPCIBusSPAPR *qpci, QTestState *qts,
>  {
>      assert(qts);
>  
> -    /* tests cannot use spapr, needs to be fixed first */
> -    qpci->bus.has_buggy_msi = true;
> -
>      qpci->alloc = alloc;
>  
>      qpci->bus.pio_readb = qpci_spapr_pio_readb;
> diff --git a/tests/qtest/libqos/pci.c b/tests/qtest/libqos/pci.c
> index a59197b9922..3bf6a0e0127 100644
> --- a/tests/qtest/libqos/pci.c
> +++ b/tests/qtest/libqos/pci.c
> @@ -53,20 +53,6 @@ void qpci_device_foreach(QPCIBus *bus, int vendor_id, int device_id,
>      }
>  }
>  
> -bool qpci_has_buggy_msi(QPCIDevice *dev)
> -{
> -    return dev->bus->has_buggy_msi;
> -}
> -
> -bool qpci_check_buggy_msi(QPCIDevice *dev)
> -{
> -    if (qpci_has_buggy_msi(dev)) {
> -        g_test_skip("Skipping due to incomplete support for MSI");
> -        return true;
> -    }
> -    return false;
> -}
> -
>  static void qpci_device_set(QPCIDevice *dev, QPCIBus *bus, int devfn)
>  {
>      g_assert(dev);
> diff --git a/tests/qtest/vhost-user-blk-test.c b/tests/qtest/vhost-user-blk-test.c
> index ea90d41232e..3e71fdb9d78 100644
> --- a/tests/qtest/vhost-user-blk-test.c
> +++ b/tests/qtest/vhost-user-blk-test.c
> @@ -554,14 +554,8 @@ static void idx(void *obj, void *u_data, QGuestAllocator *t_alloc)
>      uint32_t desc_idx;
>      uint8_t status;
>      char *data;
> -    QOSGraphObject *blk_object = obj;
> -    QPCIDevice *pci_dev = blk_object->get_driver(blk_object, "pci-device");
>      QTestState *qts = global_qtest;
>  
> -    if (qpci_check_buggy_msi(pci_dev)) {
> -        return;
> -    }
> -
>      qpci_msix_enable(pdev->pdev);
>      qvirtio_pci_set_msix_configuration_vector(pdev, t_alloc, 0);
>  
> diff --git a/tests/qtest/virtio-blk-test.c b/tests/qtest/virtio-blk-test.c
> index 98c906ebb4a..3a005d600c1 100644
> --- a/tests/qtest/virtio-blk-test.c
> +++ b/tests/qtest/virtio-blk-test.c
> @@ -474,14 +474,8 @@ static void msix(void *obj, void *u_data, QGuestAllocator *t_alloc)
>      uint32_t free_head;
>      uint8_t status;
>      char *data;
> -    QOSGraphObject *blk_object = obj;
> -    QPCIDevice *pci_dev = blk_object->get_driver(blk_object, "pci-device");
>      QTestState *qts = global_qtest;
>  
> -    if (qpci_check_buggy_msi(pci_dev)) {
> -        return;
> -    }
> -
>      qpci_msix_enable(pdev->pdev);
>      qvirtio_pci_set_msix_configuration_vector(pdev, t_alloc, 0);
>  
> @@ -584,14 +578,8 @@ static void idx(void *obj, void *u_data, QGuestAllocator *t_alloc)
>      uint32_t desc_idx;
>      uint8_t status;
>      char *data;
> -    QOSGraphObject *blk_object = obj;
> -    QPCIDevice *pci_dev = blk_object->get_driver(blk_object, "pci-device");
>      QTestState *qts = global_qtest;
>  
> -    if (qpci_check_buggy_msi(pci_dev)) {
> -        return;
> -    }
> -
>      qpci_msix_enable(pdev->pdev);
>      qvirtio_pci_set_msix_configuration_vector(pdev, t_alloc, 0);