[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v3 2/5] xen/arm: ffa: Introduce VM to VM support
Create a CONFIG_FFA_VM_TO_VM parameter to activate FFA communication between VMs. When activated list VMs in the system with FF-A support in part_info_get. When VM to VM is activated, Xen will be tainted as Insecure and a message is displayed to the user during the boot as there is no filtering of VMs in FF-A so any VM can communicate or see any other VM in the system. WARNING: There is no filtering for now and all VMs are listed !! Signed-off-by: Bertrand Marquis <bertrand.marquis@xxxxxxx> --- Changes in v3: - break partinfo_get in several sub functions to make the implementation easier to understand and lock handling easier - rework implementation to check size along the way and prevent previous implementation limits which had to check that the number of VMs or SPs did not change - taint Xen as INSECURE when VM to VM is enabled Changes in v2: - Switch ifdef to IS_ENABLED - dom was not switched to d as requested by Jan because there is already a variable d pointing to the current domain and it must not be shadowed. --- xen/arch/arm/tee/Kconfig | 11 ++ xen/arch/arm/tee/ffa.c | 12 ++ xen/arch/arm/tee/ffa_partinfo.c | 270 +++++++++++++++++++++----------- xen/arch/arm/tee/ffa_private.h | 12 ++ 4 files changed, 214 insertions(+), 91 deletions(-) diff --git a/xen/arch/arm/tee/Kconfig b/xen/arch/arm/tee/Kconfig index c5b0f88d7522..88a4c4c99154 100644 --- a/xen/arch/arm/tee/Kconfig +++ b/xen/arch/arm/tee/Kconfig @@ -28,5 +28,16 @@ config FFA [1] https://developer.arm.com/documentation/den0077/latest +config FFA_VM_TO_VM + bool "Enable FF-A between VMs (UNSUPPORTED)" if UNSUPPORTED + default n + depends on FFA + help + This option enables to use FF-A between VMs. + This is experimental and there is no access control so any + guest can communicate with any other guest. + + If unsure, say N. + endmenu diff --git a/xen/arch/arm/tee/ffa.c b/xen/arch/arm/tee/ffa.c index 3bbdd7168a6b..e41ab5f8ada6 100644 --- a/xen/arch/arm/tee/ffa.c +++ b/xen/arch/arm/tee/ffa.c @@ -464,6 +464,18 @@ static bool ffa_probe(void) printk(XENLOG_INFO "ARM FF-A Mediator version %u.%u\n", FFA_MY_VERSION_MAJOR, FFA_MY_VERSION_MINOR); + if ( IS_ENABLED(CONFIG_FFA_VM_TO_VM) ) + { + /* + * When FFA VM to VM is enabled, the current implementation does not + * offer any way to limit which VM can communicate with which VM using + * FF-A. + * Signal this in the xen console and taint the system as insecure. + * TODO: Introduce a solution to limit what a VM can do through FFA. + */ + printk(XENLOG_ERR "ffa: VM to VM is enabled, system is insecure !!\n"); + add_taint(TAINT_MACHINE_INSECURE); + } /* * psci_init_smccc() updates this value with what's reported by EL-3 * or secure world. diff --git a/xen/arch/arm/tee/ffa_partinfo.c b/xen/arch/arm/tee/ffa_partinfo.c index c0510ceb8338..93847b36cf2f 100644 --- a/xen/arch/arm/tee/ffa_partinfo.c +++ b/xen/arch/arm/tee/ffa_partinfo.c @@ -63,9 +63,152 @@ static int32_t ffa_partition_info_get(uint32_t *uuid, uint32_t flags, return ret; } -void ffa_handle_partition_info_get(struct cpu_user_regs *regs) +static int32_t ffa_get_sp_count(uint32_t *uuid, uint32_t *sp_count) +{ + uint32_t src_size; + + return ffa_partition_info_get(uuid, FFA_PARTITION_INFO_GET_COUNT_FLAG, + sp_count, &src_size); +} + +static int32_t ffa_get_sp_partinfo(uint32_t *uuid, uint32_t *sp_count, + void *dst_buf, void *end_buf, + uint32_t dst_size) { int32_t ret; + uint32_t src_size, real_sp_count; + void *src_buf = ffa_rx; + + *sp_count = 0; + + /* Do we have a RX buffer with the SPMC */ + if ( !ffa_rx ) + return FFA_RET_DENIED; + + /* We need to use the RX buffer to receive the list */ + spin_lock(&ffa_rx_buffer_lock); + + ret = ffa_partition_info_get(uuid, 0, &real_sp_count, &src_size); + if ( ret ) + goto out; + + /* We now own the RX buffer */ + + /* We only support a 1.1 firmware version */ + if ( src_size != sizeof(struct ffa_partition_info_1_1) ) + { + ret = FFA_RET_NOT_SUPPORTED; + goto out_release; + } + + for ( uint32_t sp_num = 0; sp_num < real_sp_count; sp_num++ ) + { + struct ffa_partition_info_1_1 *fpi = src_buf; + + /* filter out SP not following bit 15 convention if any */ + if ( FFA_ID_IS_SECURE(fpi->id) ) + { + if ( dst_buf + dst_size > end_buf ) + { + ret = FFA_RET_NO_MEMORY; + goto out_release; + } + + memcpy(dst_buf, src_buf, dst_size); + dst_buf += dst_size; + *sp_count += 1; + } + + src_buf += src_size; + } + +out_release: + ffa_hyp_rx_release(); +out: + spin_unlock(&ffa_rx_buffer_lock); + return ret; +} + +static uint32_t ffa_get_vm_count(void) +{ + struct domain *d = current->domain; + struct domain *dom; + uint32_t vm_count = 0; + + /* Count the number of VM with FF-A support */ + rcu_read_lock(&domlist_read_lock); + for_each_domain( dom ) + { + struct ffa_ctx *vm = dom->arch.tee; + + if (dom != d && vm != NULL && vm->guest_vers != 0) + vm_count++; + } + rcu_read_unlock(&domlist_read_lock); + + return vm_count; +} + +static int32_t ffa_get_vm_partinfo(uint32_t *vm_count, void *dst_buf, + void *end_buf, uint32_t dst_size) +{ + struct domain *d = current->domain; + struct domain *dom; + int32_t ret = FFA_RET_OK; + + *vm_count = 0; + + rcu_read_lock(&domlist_read_lock); + for_each_domain( dom ) + { + struct ffa_ctx *vm = dom->arch.tee; + + /* + * we do not add the VM calling to the list and only VMs with + * FF-A support + */ + if ( dom != d && vm != NULL && vm->guest_vers != 0 ) + { + /* + * We do not have UUID info for VMs so use + * the 1.0 structure so that we set UUIDs to + * zero using memset + */ + struct ffa_partition_info_1_0 srcvm; + + if ( dst_buf + dst_size > end_buf ) + { + ret = FFA_RET_NO_MEMORY; + goto out; + } + + srcvm.id = ffa_get_vm_id(dom); + srcvm.execution_context = dom->max_vcpus; + srcvm.partition_properties = FFA_PART_VM_PROP; + if ( is_64bit_domain(dom) ) + srcvm.partition_properties |= FFA_PART_PROP_AARCH64_STATE; + + memcpy(dst_buf, &srcvm, MIN(sizeof(srcvm), dst_size)); + + if ( dst_size > sizeof(srcvm) ) + memset(dst_buf + sizeof(srcvm), 0, + dst_size - sizeof(srcvm)); + + dst_buf += dst_size; + *vm_count += 1; + } + } + +out: + rcu_read_unlock(&domlist_read_lock); + + return ret; +} + + +void ffa_handle_partition_info_get(struct cpu_user_regs *regs) +{ + int32_t ret = FFA_RET_OK; struct domain *d = current->domain; struct ffa_ctx *ctx = d->arch.tee; uint32_t flags = get_user_reg(regs, 5); @@ -75,9 +218,9 @@ void ffa_handle_partition_info_get(struct cpu_user_regs *regs) get_user_reg(regs, 3), get_user_reg(regs, 4), }; - uint32_t src_size, dst_size; - void *dst_buf; - uint32_t ffa_sp_count = 0; + uint32_t dst_size = 0; + void *dst_buf, *end_buf; + uint32_t ffa_vm_count = 0, ffa_sp_count = 0; /* * If the guest is v1.0, he does not get back the entry size so we must @@ -89,118 +232,63 @@ void ffa_handle_partition_info_get(struct cpu_user_regs *regs) else dst_size = sizeof(struct ffa_partition_info_1_1); - /* - * FF-A v1.0 has w5 MBZ while v1.1 allows - * FFA_PARTITION_INFO_GET_COUNT_FLAG to be non-zero. - * - * FFA_PARTITION_INFO_GET_COUNT is only using registers and not the - * rxtx buffer so do the partition_info_get directly. - */ - if ( flags == FFA_PARTITION_INFO_GET_COUNT_FLAG && - ctx->guest_vers == FFA_VERSION_1_1 ) + /* Only count requested */ + if ( flags ) { + /* + * FF-A v1.0 has w5 MBZ while v1.1 allows + * FFA_PARTITION_INFO_GET_COUNT_FLAG to be non-zero. + */ + if ( ctx->guest_vers == FFA_VERSION_1_0 || + flags != FFA_PARTITION_INFO_GET_COUNT_FLAG ) + { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + if ( ffa_fw_supports_fid(FFA_PARTITION_INFO_GET) ) - ret = ffa_partition_info_get(uuid, flags, &ffa_sp_count, - &src_size); - else - ret = FFA_RET_OK; + { + ret = ffa_get_sp_count(uuid, &ffa_sp_count); + if ( ret ) + goto out; + } - goto out; - } + if ( IS_ENABLED(CONFIG_FFA_VM_TO_VM) ) + ffa_vm_count = ffa_get_vm_count(); - if ( flags ) - { - ret = FFA_RET_INVALID_PARAMETERS; - goto out; - } - - if ( !ffa_fw_supports_fid(FFA_PARTITION_INFO_GET) ) - { - /* Just give an empty partition list to the caller */ - ret = FFA_RET_OK; goto out; } + /* Get the RX buffer to write the list of partitions */ ret = ffa_rx_acquire(d); if ( ret != FFA_RET_OK ) goto out; dst_buf = ctx->rx; + end_buf = ctx->rx + ctx->page_count * FFA_PAGE_SIZE; - if ( !ffa_rx ) + if ( ffa_fw_supports_fid(FFA_PARTITION_INFO_GET) ) { - ret = FFA_RET_DENIED; - goto out_rx_release; - } - - spin_lock(&ffa_rx_buffer_lock); - - ret = ffa_partition_info_get(uuid, 0, &ffa_sp_count, &src_size); + ret = ffa_get_sp_partinfo(uuid, &ffa_sp_count, dst_buf, end_buf, + dst_size); - if ( ret ) - goto out_rx_hyp_unlock; + if ( ret ) + goto out_rx_release; - /* - * ffa_partition_info_get() succeeded so we now own the RX buffer we - * share with the SPMC. We must give it back using ffa_hyp_rx_release() - * once we've copied the content. - */ - - /* we cannot have a size smaller than 1.0 structure */ - if ( src_size < sizeof(struct ffa_partition_info_1_0) ) - { - ret = FFA_RET_NOT_SUPPORTED; - goto out_rx_hyp_release; - } - - if ( ctx->page_count * FFA_PAGE_SIZE < ffa_sp_count * dst_size ) - { - ret = FFA_RET_NO_MEMORY; - goto out_rx_hyp_release; + dst_buf += ffa_sp_count * dst_size; } - if ( ffa_sp_count > 0 ) - { - uint32_t n, n_limit = ffa_sp_count; - void *src_buf = ffa_rx; - - /* copy the secure partitions info */ - for ( n = 0; n < n_limit; n++ ) - { - struct ffa_partition_info_1_1 *fpi = src_buf; - - /* filter out SP not following bit 15 convention if any */ - if ( FFA_ID_IS_SECURE(fpi->id) ) - { - memcpy(dst_buf, src_buf, dst_size); - dst_buf += dst_size; - } - else - ffa_sp_count--; + if ( IS_ENABLED(CONFIG_FFA_VM_TO_VM) ) + ret = ffa_get_vm_partinfo(&ffa_vm_count, dst_buf, end_buf, dst_size); - src_buf += src_size; - } - } - -out_rx_hyp_release: - ffa_hyp_rx_release(); -out_rx_hyp_unlock: - spin_unlock(&ffa_rx_buffer_lock); out_rx_release: - /* - * The calling VM RX buffer only contains data to be used by the VM if the - * call was successful, in which case the VM has to release the buffer - * once it has used the data. - * If something went wrong during the call, we have to release the RX - * buffer back to the SPMC as the VM will not do it. - */ - if ( ret != FFA_RET_OK ) + if ( ret ) ffa_rx_release(d); out: if ( ret ) ffa_set_regs_error(regs, ret); else - ffa_set_regs_success(regs, ffa_sp_count, dst_size); + ffa_set_regs_success(regs, ffa_sp_count + ffa_vm_count, dst_size); } static int32_t ffa_direct_req_send_vm(uint16_t sp_id, uint16_t vm_id, diff --git a/xen/arch/arm/tee/ffa_private.h b/xen/arch/arm/tee/ffa_private.h index c4cd65538908..bd6877d8c632 100644 --- a/xen/arch/arm/tee/ffa_private.h +++ b/xen/arch/arm/tee/ffa_private.h @@ -187,6 +187,18 @@ */ #define FFA_PARTITION_INFO_GET_COUNT_FLAG BIT(0, U) +/* + * Partition properties we give for a normal world VM: + * - can send direct message but not receive them + * - can handle indirect messages + * - can receive notifications + * 32/64 bit flag is set depending on the VM + */ +#define FFA_PART_VM_PROP (FFA_PART_PROP_DIRECT_REQ_SEND | \ + FFA_PART_PROP_INDIRECT_MSGS | \ + FFA_PART_PROP_RECV_NOTIF | \ + FFA_PART_PROP_IS_PE_ID) + /* Flags used in calls to FFA_NOTIFICATION_GET interface */ #define FFA_NOTIF_FLAG_BITMAP_SP BIT(0, U) #define FFA_NOTIF_FLAG_BITMAP_VM BIT(1, U) -- 2.47.1
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