On 2016-02-21 16:54, Marcel Apfelbaum wrote: > On 02/21/2016 03:40 PM, Jan Kiszka wrote: >> On 2016-02-21 13:08, Marcel Apfelbaum wrote: >>> On 02/21/2016 01:38 PM, Marcel Apfelbaum wrote: >>>> On 02/19/2016 05:30 AM, Peter Xu wrote: >>>>> To enable interrupt remapping for intel IOMMU device, each IOAPIC >>>>> device >>>>> in the system reported via ACPI MADT must be explicitly enumerated >>>>> under >>>>> one specific remapping hardware unit. This patch adds the root-complex >>>>> IOAPIC into the default DMAR device. >>>>> >>>>> Please refer to VT-d spec 8.3.1.1 for more information. >>>>> >>>>> Signed-off-by: Peter Xu <pet...@redhat.com> >>>>> --- >>>>> hw/i386/acpi-build.c | 23 +++++++++++++++++++++-- >>>>> include/hw/acpi/acpi-defs.h | 15 +++++++++++++++ >>>>> 2 files changed, 36 insertions(+), 2 deletions(-) >>>>> >>>>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c >>>>> index d9e4f91..1cefe43 100644 >>>>> --- a/hw/i386/acpi-build.c >>>>> +++ b/hw/i386/acpi-build.c >>>>> @@ -76,6 +76,9 @@ >>>>> #define ACPI_BUILD_DPRINTF(fmt, ...) >>>>> #endif >>>>> >>>>> +/* Default IOAPIC ID */ >>>>> +#define ACPI_BUILD_IOAPIC_ID 0x0 >>>>> + >>>>> typedef struct AcpiCpuInfo { >>>>> DECLARE_BITMAP(found_cpus, ACPI_CPU_HOTPLUG_ID_LIMIT); >>>>> } AcpiCpuInfo; >>>>> @@ -392,7 +395,6 @@ build_madt(GArray *table_data, GArray *linker, >>>>> AcpiCpuInfo *cpu) >>>>> io_apic = acpi_data_push(table_data, sizeof *io_apic); >>>>> io_apic->type = ACPI_APIC_IO; >>>>> io_apic->length = sizeof(*io_apic); >>>>> -#define ACPI_BUILD_IOAPIC_ID 0x0 >>>>> io_apic->io_apic_id = ACPI_BUILD_IOAPIC_ID; >>>>> io_apic->address = cpu_to_le32(IO_APIC_DEFAULT_ADDRESS); >>>>> io_apic->interrupt = cpu_to_le32(0); >>>>> @@ -2511,6 +2513,9 @@ build_dmar_q35(GArray *table_data, GArray >>>>> *linker) >>>>> AcpiDmarHardwareUnit *drhd; >>>>> uint8_t dmar_flags = 0; >>>>> IntelIOMMUState *intel_iommu = acpi_get_iommu(); >>>>> + AcpiDmarDeviceScope *scope = NULL; >>>>> + /* Root complex IOAPIC use one path[0] only */ >>>>> + uint16_t scope_size = sizeof(*scope) + sizeof(uint16_t); >>>>> >>>>> assert(intel_iommu); >>>>> >>>>> @@ -2526,11 +2531,25 @@ build_dmar_q35(GArray *table_data, GArray >>>>> *linker) >>>>> /* DMAR Remapping Hardware Unit Definition structure */ >>>>> drhd = acpi_data_push(table_data, sizeof(*drhd)); >>>>> drhd->type = cpu_to_le16(ACPI_DMAR_TYPE_HARDWARE_UNIT); >>>>> - drhd->length = cpu_to_le16(sizeof(*drhd)); /* No device scope >>>>> now */ >>>>> + drhd->length = cpu_to_le16(sizeof(*drhd) + scope_size); >>>>> drhd->flags = ACPI_DMAR_INCLUDE_PCI_ALL; >>>>> drhd->pci_segment = cpu_to_le16(0); >>>>> drhd->address = cpu_to_le64(Q35_HOST_BRIDGE_IOMMU_ADDR); >>>>> >>>>> + /* Scope definition for the root-complex IOAPIC */ >>>>> + scope = acpi_data_push(table_data, scope_size); >>>>> + scope->entry_type = cpu_to_le16(ACPI_DMAR_DEV_SCOPE_TYPE_IOAPIC); >>>>> + scope->length = scope_size; >>>>> + /* >>>>> + * An arbitary but unique bus number, to be used to generate >>>>> + * source ID for IOAPIC device in BDF format. >>>>> + */ >>>>> +#define ACPI_IOAPIC_BUS_IR (0xf0) >>>>> +#define ACPI_IOAPIC_DEVFN_IR (0x00) >>>> >>>> Hi, >>>> >>>> How do you know for sure there is no bus (or bus & device) having the >>>> number 0xf0 in the system? >>>> Now that we support multiple Root Complexes, using the pxb-pcie >>>> device we can simply add a PCI root bus like this: >>>> -device pxb-pcie,bus_nr=0xf0 >>>> or we can add enough switches to get to this number. >>>> >>>> You could dynamically query for an unused PCI bus, but the number >>>> would change between the runs. >>>> Or, I suppose you can reserve a slot on bus 0 for that. It is >>>> interesting how it works on a real machine. >>> >>> thinking about it more, maybe we should let the firmware to assign the >>> bus/dev/fun for the IO APIC? >> >> We have the same problem over with VT-d and IR. >> >> I don't think the firmware is not the right place, otherwise there would >> be an interface in hw to adjust that parameters. I think we should >> simply make sure that the qemu user cannot assign devices to those >> addresses as they are reserved for the platform devices (the HPET >> requires another ID), or even reserve the hole bus for the platform. > > > I understand, but it is the firmware that assign addresses, not QEMU/user.
Right, buses are chosen by the firmware, but device address are (optionally) under user control. > We need a way to tell the firmware not to use a certain address range, > we can do that > with fw_config I suppose. The pseudo addresses of IOAPIC and HPET are part of ACPI tables, both on AMD and Intel. Firmware can evaluate them easily. > > Reserving a bus might be easier, we take the bus number out from host > bridges CRS > ranges and each platform device can be assigned a slot. We would need to > select the bus carefully > to not collide with other PCI hierarchies. Maybe bus 0xFF. Yes, that's the bus number I once chose for Intel / Q35. Jan
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