According to the Arm architecture, SMMU-originated memory accesses, such as fetching commands or writing events for a secure stream, must target the Secure Physical Address (PA) space. The existing model sends all DMA to the global non-secure address_space_memory.
This patch introduces the infrastructure to differentiate between secure and non-secure memory accesses. Firstly, SMMU_SEC_SID_S is added in SMMUSecSID enum to represent the secure context. Then a weak global symbol, arm_secure_address_space, is added, which can be provided by the machine model to represent the Secure PA space. A new helper, smmu_get_address_space(), selects the target address space based on SEC_SID. All internal DMA calls (dma_memory_read/write) will be updated to use this helper in follow-up patches. Signed-off-by: Tao Tang <[email protected]> --- hw/arm/smmu-common.c | 8 ++++++++ hw/arm/virt.c | 5 +++++ include/hw/arm/smmu-common.h | 27 +++++++++++++++++++++++++++ 3 files changed, 40 insertions(+) diff --git a/hw/arm/smmu-common.c b/hw/arm/smmu-common.c index 62a7612184..24db448683 100644 --- a/hw/arm/smmu-common.c +++ b/hw/arm/smmu-common.c @@ -30,6 +30,14 @@ #include "hw/arm/smmu-common.h" #include "smmu-internal.h" +/* Global state for secure address space availability */ +bool arm_secure_as_available; + +void smmu_enable_secure_address_space(void) +{ + arm_secure_as_available = true; +} + /* IOTLB Management */ static guint smmu_iotlb_key_hash(gconstpointer v) diff --git a/hw/arm/virt.c b/hw/arm/virt.c index 175023897a..83dc62a095 100644 --- a/hw/arm/virt.c +++ b/hw/arm/virt.c @@ -92,6 +92,8 @@ #include "hw/cxl/cxl_host.h" #include "qemu/guest-random.h" +AddressSpace arm_secure_address_space; + static GlobalProperty arm_virt_compat[] = { { TYPE_VIRTIO_IOMMU_PCI, "aw-bits", "48" }, }; @@ -2257,6 +2259,9 @@ static void machvirt_init(MachineState *machine) memory_region_init(secure_sysmem, OBJECT(machine), "secure-memory", UINT64_MAX); memory_region_add_subregion_overlap(secure_sysmem, 0, sysmem, -1); + address_space_init(&arm_secure_address_space, secure_sysmem, + "secure-memory-space"); + smmu_enable_secure_address_space(); } firmware_loaded = virt_firmware_init(vms, sysmem, diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h index b0dae18a62..d54558f94b 100644 --- a/include/hw/arm/smmu-common.h +++ b/include/hw/arm/smmu-common.h @@ -43,9 +43,36 @@ /* StreamID Security state */ typedef enum SMMUSecSID { SMMU_SEC_SID_NS = 0, + SMMU_SEC_SID_S, SMMU_SEC_SID_NUM, } SMMUSecSID; +extern AddressSpace __attribute__((weak)) arm_secure_address_space; +extern bool arm_secure_as_available; +void smmu_enable_secure_address_space(void); + +/* + * Return the address space corresponding to the SEC_SID. + * If SEC_SID is Secure, but secure address space is not available, + * return NULL and print a warning message. + */ +static inline AddressSpace *smmu_get_address_space(SMMUSecSID sec_sid) +{ + switch (sec_sid) { + case SMMU_SEC_SID_NS: + return &address_space_memory; + case SMMU_SEC_SID_S: + if (!arm_secure_as_available || arm_secure_address_space.root == NULL) { + printf("Secure address space requested but not available"); + return NULL; + } + return &arm_secure_address_space; + default: + printf("Unknown SEC_SID value %d", sec_sid); + return NULL; + } +} + /* * Page table walk error types */ -- 2.34.1
