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.h | 1 + 1 file changed, 1 insertion(+) (limited to 'hw/spapr.h') diff --git a/hw/spapr.h b/hw/spapr.h index 51a966b1e9..e984e3fc3c 100644 --- a/hw/spapr.h +++ b/hw/spapr.h @@ -339,6 +339,7 @@ void spapr_iommu_init(void); DMAContext *spapr_tce_new_dma_context(uint32_t liobn, size_t window_size); void spapr_tce_free(DMAContext *dma); void spapr_tce_reset(DMAContext *dma); +void spapr_tce_set_bypass(DMAContext *dma, bool bypass); int spapr_dma_dt(void *fdt, int node_off, const char *propname, uint32_t liobn, uint64_t window, uint32_t size); int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname, -- cgit v1.2.3