From 1b6f99d84f21473cf2d1adab312dd28dd315a083 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Fri, 3 Jul 2020 16:59:42 +0100 Subject: [PATCH] hw/arm/virt: Let the virtio-iommu bypass MSIs At the moment the virtio-iommu translates MSI transactions. This behavior is inherited from ARM SMMU. The virt machine code knows where the guest MSI doorbells are so we can easily declare those regions as VIRTIO_IOMMU_RESV_MEM_T_MSI. With that setting the guest will not map MSIs through the IOMMU and those transactions will be simply bypassed. Depending on which MSI controller is in use (ITS or GICV2M), we declare either: - the ITS interrupt translation space (ITS_base + 0x10000), containing the GITS_TRANSLATOR or - The GICV2M single frame, containing the MSI_SETSP_NS register. Signed-off-by: Eric Auger Message-id: 20200629070404.10969-6-eric.auger@redhat.com Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/arm/virt.c | 30 ++++++++++++++++++++++++++++++ include/hw/arm/virt.h | 7 +++++++ 2 files changed, 37 insertions(+) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index af3050bc4b..7922f3c23a 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -600,6 +600,7 @@ static void create_its(VirtMachineState *vms) sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, vms->memmap[VIRT_GIC_ITS].base); fdt_add_its_gic_node(vms); + vms->msi_controller = VIRT_MSI_CTRL_ITS; } static void create_v2m(VirtMachineState *vms) @@ -620,6 +621,7 @@ static void create_v2m(VirtMachineState *vms) } fdt_add_v2m_gic_node(vms); + vms->msi_controller = VIRT_MSI_CTRL_GICV2M; } static void create_gic(VirtMachineState *vms) @@ -2198,8 +2200,36 @@ out: static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev, Error **errp) { + VirtMachineState *vms = VIRT_MACHINE(hotplug_dev); + if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) { virt_memory_pre_plug(hotplug_dev, dev, errp); + } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_IOMMU_PCI)) { + hwaddr db_start = 0, db_end = 0; + char *resv_prop_str; + + switch (vms->msi_controller) { + case VIRT_MSI_CTRL_NONE: + return; + case VIRT_MSI_CTRL_ITS: + /* GITS_TRANSLATER page */ + db_start = base_memmap[VIRT_GIC_ITS].base + 0x10000; + db_end = base_memmap[VIRT_GIC_ITS].base + + base_memmap[VIRT_GIC_ITS].size - 1; + break; + case VIRT_MSI_CTRL_GICV2M: + /* MSI_SETSPI_NS page */ + db_start = base_memmap[VIRT_GIC_V2M].base; + db_end = db_start + base_memmap[VIRT_GIC_V2M].size - 1; + break; + } + resv_prop_str = g_strdup_printf("0x%"PRIx64":0x%"PRIx64":%u", + db_start, db_end, + VIRTIO_IOMMU_RESV_MEM_T_MSI); + + qdev_prop_set_uint32(dev, "len-reserved-regions", 1); + qdev_prop_set_string(dev, "reserved-regions[0]", resv_prop_str); + g_free(resv_prop_str); } } diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h index 31878ddc72..a18b6b397b 100644 --- a/include/hw/arm/virt.h +++ b/include/hw/arm/virt.h @@ -96,6 +96,12 @@ typedef enum VirtIOMMUType { VIRT_IOMMU_VIRTIO, } VirtIOMMUType; +typedef enum VirtMSIControllerType { + VIRT_MSI_CTRL_NONE, + VIRT_MSI_CTRL_GICV2M, + VIRT_MSI_CTRL_ITS, +} VirtMSIControllerType; + typedef enum VirtGICType { VIRT_GIC_VERSION_MAX, VIRT_GIC_VERSION_HOST, @@ -136,6 +142,7 @@ typedef struct { OnOffAuto acpi; VirtGICType gic_version; VirtIOMMUType iommu; + VirtMSIControllerType msi_controller; uint16_t virtio_iommu_bdf; struct arm_boot_info bootinfo; MemMapEntry *memmap; -- 2.11.4.GIT