Introduce a new pci_preserve_config field in virt machine state which allows the generation of DSM #5. This field is only set if accel SMMU is instantiated.
In a subsequent patch, SMMUv3 accel mode will make use of IORT RMR nodes to enable nested translation of MSI doorbell addresses. IORT RMR requires _DSM #5 to be set for the PCI host bridge so that the Guest kernel preserves the PCI boot configuration. Reviewed-by: Jonathan Cameron <[email protected]> Tested-by: Zhangfei Gao <[email protected]> Reviewed-by: Eric Auger <[email protected]> Signed-off-by: Shameer Kolothum <[email protected]> --- hw/arm/virt-acpi-build.c | 8 ++++++++ hw/arm/virt.c | 1 + include/hw/arm/virt.h | 1 + 3 files changed, 10 insertions(+) diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c index 03b4342574..9032a5df1c 100644 --- a/hw/arm/virt-acpi-build.c +++ b/hw/arm/virt-acpi-build.c @@ -164,6 +164,14 @@ static void acpi_dsdt_add_pci(Aml *scope, const MemMapEntry *memmap, .pci_native_hotplug = !acpi_pcihp, }; + /* + * Accel SMMU requires RMRs for MSI 1-1 mapping, which require _DSM + * function 5 (_DSM for Preserving PCI Boot Configurations). + */ + if (vms->pci_preserve_config) { + cfg.preserve_config = true; + } + if (vms->highmem_mmio) { cfg.mmio64 = memmap[VIRT_HIGH_PCIE_MMIO]; } diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 08feadf0a8..d0321cea2d 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -3071,6 +3071,7 @@ static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev, } object_property_set_uint(OBJECT(dev), "msi-gpa", db_start, &error_abort); + vms->pci_preserve_config = true; } } } diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h index 8694aaa4e2..2147c6beb4 100644 --- a/include/hw/arm/virt.h +++ b/include/hw/arm/virt.h @@ -180,6 +180,7 @@ struct VirtMachineState { bool ns_el2_virt_timer_irq; CXLState cxl_devices_state; bool legacy_smmuv3_present; + bool pci_preserve_config; }; #define VIRT_ECAM_ID(high) (high ? VIRT_HIGH_PCIE_ECAM : VIRT_PCIE_ECAM) -- 2.43.0
