From 53724ee565565f69560dbe17553bede8c0169379 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 12 Sep 2012 16:57:20 +0000 Subject: pseries: Rework implementation of TCE bypass On the pseries machine the IOMMU (aka TCE tables) is always active for all PCI and VIO devices. Mostly to simplify the SLOF firmware, we implement an extension which allows the IOMMU to be temporarily disabled for certain devices. Currently this is implemented by setting the device's DMAContext pointer to NULL (thus reverting to qemu's default no-IOMMU DMA behaviour), then replacing it when bypass mode is disabled. This approach causes a bunch of complications though. It complexifies the management of the DMAContext lifetimes, it's problematic for savevm/loadvm, and it means that while bypass is active we have nowhere to store the device's LIOBN (Logical IO Bus Number, used to identify DMA address spaces). At present we regenerate the LIOBN from other address information but this restricts how we can allocate LIOBNs. This patch gives up on this approach, replacing it with the much simpler one of having a 'bypass' boolean flag in the TCE state structure. Signed-off-by: David Gibson Signed-off-by: Alexander Graf --- hw/spapr_vio.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) (limited to 'hw/spapr_vio.c') diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c index 752836e76c..848806d3f1 100644 --- a/hw/spapr_vio.c +++ b/hw/spapr_vio.c @@ -316,14 +316,9 @@ int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq) static void spapr_vio_quiesce_one(VIOsPAPRDevice *dev) { - VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev); - uint32_t liobn = SPAPR_VIO_BASE_LIOBN | dev->reg; - if (dev->dma) { - spapr_tce_free(dev->dma); + spapr_tce_reset(dev->dma); } - dev->dma = spapr_tce_new_dma_context(liobn, pc->rtce_window_size); - free_crq(dev); } @@ -346,16 +341,14 @@ static void rtas_set_tce_bypass(sPAPREnvironment *spapr, uint32_t token, rtas_st(rets, 0, -3); return; } - if (enable) { - spapr_tce_free(dev->dma); - dev->dma = NULL; - } else { - VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev); - uint32_t liobn = SPAPR_VIO_BASE_LIOBN | dev->reg; - dev->dma = spapr_tce_new_dma_context(liobn, pc->rtce_window_size); + if (!dev->dma) { + rtas_st(rets, 0, -3); + return; } + spapr_tce_set_bypass(dev->dma, !!enable); + rtas_st(rets, 0, 0); } @@ -421,7 +414,6 @@ static int spapr_vio_busdev_init(DeviceState *qdev) { VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev; VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev); - uint32_t liobn; char *id; if (dev->reg != -1) { @@ -463,8 +455,10 @@ static int spapr_vio_busdev_init(DeviceState *qdev) return -1; } - liobn = SPAPR_VIO_BASE_LIOBN | dev->reg; - dev->dma = spapr_tce_new_dma_context(liobn, pc->rtce_window_size); + if (pc->rtce_window_size) { + uint32_t liobn = SPAPR_VIO_BASE_LIOBN | dev->reg; + dev->dma = spapr_tce_new_dma_context(liobn, pc->rtce_window_size); + } return pc->init(dev); } -- cgit v1.2.3