From: Luigi Leonardi <[email protected]> Coconut SVSM, with the upcoming device tree support [1], will use the IGVM device tree parameter to discover virtio-mmio and ISA serial devices instead of relying on the fw_cfg interface, which is QEMU-specific.
The device tree is packed before copying into the IGVM parameter area to reduce its size, since IGVM files can define tighter memory constraints for parameter areas. Packing is done in the generic IGVM backend rather than in per-architecture device tree setup code, so that each architecture does not need to handle it individually. [1] https://github.com/coconut-svsm/svsm/pull/1006 Signed-off-by: Luigi Leonardi <[email protected]> Reviewed-by: Stefano Garzarella <[email protected]> Message-ID: <[email protected]> Signed-off-by: Gerd Hoffmann <[email protected]> --- backends/igvm.c | 54 ++++++++++++++++++++++++++++++++++++++++++++ backends/meson.build | 2 +- 2 files changed, 55 insertions(+), 1 deletion(-) diff --git a/backends/igvm.c b/backends/igvm.c index a5a2a4eccc19..80e87fe6029a 100644 --- a/backends/igvm.c +++ b/backends/igvm.c @@ -26,6 +26,10 @@ #include <igvm/igvm.h> #include <igvm/igvm_defs.h> +#ifdef CONFIG_FDT +#include <libfdt.h> +#endif + #ifndef IGVM_VHT_OPTIONAL_BIT #define IGVM_VHT_OPTIONAL_BIT (1U << 31) #endif @@ -121,6 +125,10 @@ static int qigvm_directive_snp_id_block(QIgvm *ctx, const uint8_t *header_data, static int qigvm_initialization_guest_policy(QIgvm *ctx, const uint8_t *header_data, Error **errp); +#ifdef CONFIG_FDT +static int qigvm_directive_device_tree(QIgvm *ctx, const uint8_t *header_data, + Error **errp); +#endif struct QIGVMHandler { IgvmVariableHeaderType type; @@ -151,6 +159,10 @@ static struct QIGVMHandler handlers[] = { qigvm_initialization_guest_policy }, { IGVM_VHT_MADT, IGVM_HEADER_SECTION_DIRECTIVE, qigvm_directive_madt }, +#ifdef CONFIG_FDT + { IGVM_VHT_DEVICE_TREE, IGVM_HEADER_SECTION_DIRECTIVE, + qigvm_directive_device_tree }, +#endif }; static int qigvm_handler(QIgvm *ctx, IgvmVariableHeaderType raw_type, @@ -786,6 +798,48 @@ static int qigvm_directive_snp_id_block(QIgvm *ctx, const uint8_t *header_data, return 0; } +#ifdef CONFIG_FDT +static int qigvm_directive_device_tree(QIgvm *ctx, const uint8_t *header_data, + Error **errp) +{ + const IGVM_VHS_PARAMETER *param = (const IGVM_VHS_PARAMETER *)header_data; + g_autofree void *fdt_packed = NULL; + QIgvmParameterData *param_entry; + uint32_t fdt_size; + + param_entry = qigvm_find_param_entry(ctx, + param->parameter_area_index, errp); + if (param_entry == NULL) { + return -1; + } + + if (ctx->machine_state->fdt == NULL) { + error_setg(errp, "IGVM: device tree not available"); + return -1; + } + + fdt_size = fdt_totalsize(ctx->machine_state->fdt); + fdt_packed = g_memdup2(ctx->machine_state->fdt, fdt_size); + + if (fdt_pack(fdt_packed)) { + error_setg(errp, "IGVM: failed to pack device tree"); + return -1; + } + + fdt_size = fdt_totalsize(fdt_packed); + if (fdt_size > param_entry->size) { + error_setg(errp, + "IGVM: device tree size exceeds parameter area" + " defined in IGVM file"); + return -1; + } + + memcpy(param_entry->data, fdt_packed, fdt_size); + + return 0; +} +#endif + static int qigvm_initialization_guest_policy(QIgvm *ctx, const uint8_t *header_data, Error **errp) { diff --git a/backends/meson.build b/backends/meson.build index aabfaea5fd8d..8792c58c361f 100644 --- a/backends/meson.build +++ b/backends/meson.build @@ -35,7 +35,7 @@ endif system_ss.add(when: gio, if_true: files('dbus-vmstate.c')) system_ss.add(when: 'CONFIG_SGX', if_true: files('hostmem-epc.c')) -system_ss.add(when: igvm, if_true: [files('igvm-cfg.c', 'igvm.c')]) +system_ss.add(when: igvm, if_true: [files('igvm-cfg.c', 'igvm.c'), fdt]) system_ss.add(when: 'CONFIG_SPDM_SOCKET', if_true: files('spdm-socket.c')) -- 2.55.0
