From ccc23bb08a84f3709b08cc10ffd4e819832fae6d Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Mon, 17 Dec 2018 15:31:12 +0800 Subject: [PATCH] intel_iommu: dma read/write draining support Support DMA read/write draining should be easy for existing VT-d emulation since the emulation itself does not have any request queue there so we don't need to do anything to flush the un-commited queue. What we need to do is to declare the support. These capabilities are required to pass Windows SVVP test program. It is verified that when with parameters "x-aw-bits=48,caching-mode=off" we can pass the Windows SVVP test with this patch applied. Otherwise we'll fail with: IOMMU[0] - DWD (DMA write draining) not supported IOMMU[0] - DWD (DMA read draining) not supported Segment 0 has no DMA remapping capable IOMMU units However since these bits are not declared support for QEMU<=3.1, we'll need a compatibility bit for it and we turn this on by default only for QEMU>=4.0. Please refer to VT-d spec 6.5.4 for more information. CC: Yu Wang Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1654550 Signed-off-by: Peter Xu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/i386/intel_iommu.c | 4 ++++ hw/i386/intel_iommu_internal.h | 3 +++ include/hw/i386/intel_iommu.h | 1 + include/hw/i386/pc.h | 5 +++++ 4 files changed, 13 insertions(+) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 4806d7edb4..26cc731c7b 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -2659,6 +2659,7 @@ static Property vtd_properties[] = { DEFINE_PROP_UINT8("x-aw-bits", IntelIOMMUState, aw_bits, VTD_HOST_ADDRESS_WIDTH), DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE), + DEFINE_PROP_BOOL("dma-drain", IntelIOMMUState, dma_drain, true), DEFINE_PROP_END_OF_LIST(), }; @@ -3147,6 +3148,9 @@ static void vtd_init(IntelIOMMUState *s) s->cap = VTD_CAP_FRO | VTD_CAP_NFR | VTD_CAP_ND | VTD_CAP_MAMV | VTD_CAP_PSI | VTD_CAP_SLLPS | VTD_CAP_SAGAW_39bit | VTD_CAP_MGAW(s->aw_bits); + if (s->dma_drain) { + s->cap |= VTD_CAP_DRAIN; + } if (s->aw_bits == VTD_HOST_AW_48BIT) { s->cap |= VTD_CAP_SAGAW_48bit; } diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h index d084099ed9..00e9edbc66 100644 --- a/hw/i386/intel_iommu_internal.h +++ b/hw/i386/intel_iommu_internal.h @@ -203,6 +203,9 @@ #define VTD_CAP_MAMV (VTD_MAMV << 48) #define VTD_CAP_PSI (1ULL << 39) #define VTD_CAP_SLLPS ((1ULL << 34) | (1ULL << 35)) +#define VTD_CAP_DRAIN_WRITE (1ULL << 54) +#define VTD_CAP_DRAIN_READ (1ULL << 55) +#define VTD_CAP_DRAIN (VTD_CAP_DRAIN_READ | VTD_CAP_DRAIN_WRITE) #define VTD_CAP_CM (1ULL << 7) /* Supported Adjusted Guest Address Widths */ diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h index ed4e758273..a321cc9691 100644 --- a/include/hw/i386/intel_iommu.h +++ b/include/hw/i386/intel_iommu.h @@ -245,6 +245,7 @@ struct IntelIOMMUState { OnOffAuto intr_eim; /* Toggle for EIM cabability */ bool buggy_eim; /* Force buggy EIM unless eim=off */ uint8_t aw_bits; /* Host/IOVA address width (in bits) */ + bool dma_drain; /* Whether DMA r/w draining enabled */ /* * Protects IOMMU states in general. Currently it protects the diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index 9d29c4b1df..c7c0c944e8 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -296,6 +296,11 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *); #define PC_COMPAT_3_1 \ HW_COMPAT_3_1 \ + {\ + .driver = "intel-iommu",\ + .property = "dma-drain",\ + .value = "off",\ + }, #define PC_COMPAT_3_0 \ HW_COMPAT_3_0 \