[PATCH V3 4/8] hw/riscv/virt: Enable basic ACPI infrastructure

[Sunil V L <sunilvl@ventanamicro.com>]

Add basic ACPI infrastructure for RISC-V with below tables.
        1) DSDT with below basic objects
                - CPUs
                - fw_cfg
        2) FADT revision 6 with HW_REDUCED flag
        3) XSDT
        4) RSDP

Add this functionality in a new file virt-acpi-build.c and enable
building this infrastructure.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
---
 hw/riscv/Kconfig           |   1 +
 hw/riscv/meson.build       |   1 +
 hw/riscv/virt-acpi-build.c | 267 +++++++++++++++++++++++++++++++++++++
 include/hw/riscv/virt.h    |   1 +
 4 files changed, 270 insertions(+)
 create mode 100644 hw/riscv/virt-acpi-build.c

diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
index 4550b3b938..6528ebfa3a 100644
--- a/hw/riscv/Kconfig
+++ b/hw/riscv/Kconfig
@@ -44,6 +44,7 @@ config RISCV_VIRT
     select VIRTIO_MMIO
     select FW_CFG_DMA
     select PLATFORM_BUS
+    select ACPI
 
 config SHAKTI_C
     bool
diff --git a/hw/riscv/meson.build b/hw/riscv/meson.build
index ab6cae57ea..2f7ee81be3 100644
--- a/hw/riscv/meson.build
+++ b/hw/riscv/meson.build
@@ -9,5 +9,6 @@ riscv_ss.add(when: 'CONFIG_SIFIVE_E', if_true: files('sifive_e.c'))
 riscv_ss.add(when: 'CONFIG_SIFIVE_U', if_true: files('sifive_u.c'))
 riscv_ss.add(when: 'CONFIG_SPIKE', if_true: files('spike.c'))
 riscv_ss.add(when: 'CONFIG_MICROCHIP_PFSOC', if_true: files('microchip_pfsoc.c'))
+riscv_ss.add(when: 'CONFIG_ACPI', if_true: files('virt-acpi-build.c'))
 
 hw_arch += {'riscv': riscv_ss}
diff --git a/hw/riscv/virt-acpi-build.c b/hw/riscv/virt-acpi-build.c
new file mode 100644
index 0000000000..30af974db3
--- /dev/null
+++ b/hw/riscv/virt-acpi-build.c
@@ -0,0 +1,267 @@
+/*
+ * Support for generating ACPI tables and passing them to Guests
+ *
+ * RISC-V virt ACPI generation
+ *
+ * Copyright (C) 2008-2010  Kevin O'Connor <kevin@koconnor.net>
+ * Copyright (C) 2006 Fabrice Bellard
+ * Copyright (C) 2013 Red Hat Inc
+ * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO.,LTD.
+ * Copyright (C) 2021-2023 Ventana Micro Systems Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/acpi/acpi-defs.h"
+#include "hw/acpi/acpi.h"
+#include "hw/acpi/aml-build.h"
+#include "hw/acpi/utils.h"
+#include "qapi/error.h"
+#include "sysemu/reset.h"
+#include "migration/vmstate.h"
+#include "hw/riscv/virt.h"
+
+#define ACPI_BUILD_TABLE_SIZE             0x20000
+
+typedef struct AcpiBuildState {
+    /* Copy of table in RAM (for patching) */
+    MemoryRegion *table_mr;
+    MemoryRegion *rsdp_mr;
+    MemoryRegion *linker_mr;
+    /* Is table patched? */
+    bool patched;
+} AcpiBuildState;
+
+static void acpi_dsdt_add_cpus(Aml *scope, RISCVVirtState *s)
+{
+    MachineState *ms = MACHINE(s);
+    uint16_t i;
+
+    for (i = 0; i < ms->smp.cpus; i++) {
+        Aml *dev = aml_device("C%.03X", i);
+        aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0007")));
+        aml_append(dev, aml_name_decl("_UID", aml_int(i)));
+        aml_append(scope, dev);
+    }
+}
+
+static void acpi_dsdt_add_fw_cfg(Aml *scope, const MemMapEntry *fw_cfg_memmap)
+{
+    Aml *dev = aml_device("FWCF");
+    aml_append(dev, aml_name_decl("_HID", aml_string("QEMU0002")));
+
+    /* device present, functioning, decoding, not shown in UI */
+    aml_append(dev, aml_name_decl("_STA", aml_int(0xB)));
+    aml_append(dev, aml_name_decl("_CCA", aml_int(1)));
+
+    Aml *crs = aml_resource_template();
+    aml_append(crs, aml_memory32_fixed(fw_cfg_memmap->base,
+                                       fw_cfg_memmap->size, AML_READ_WRITE));
+    aml_append(dev, aml_name_decl("_CRS", crs));
+    aml_append(scope, dev);
+}
+
+/* FADT */
+static void build_fadt_rev6(GArray *table_data,
+                            BIOSLinker *linker,
+                            RISCVVirtState *s,
+                            unsigned dsdt_tbl_offset)
+{
+    AcpiFadtData fadt = {
+        .rev = 6,
+        .minor_ver = 0,
+        .flags = 1 << ACPI_FADT_F_HW_REDUCED_ACPI,
+        .xdsdt_tbl_offset = &dsdt_tbl_offset,
+    };
+
+    build_fadt(table_data, linker, &fadt, s->oem_id, s->oem_table_id);
+}
+
+/* DSDT */
+static void build_dsdt(GArray *table_data,
+                       BIOSLinker *linker,
+                       RISCVVirtState *s)
+{
+    Aml *scope, *dsdt;
+    const MemMapEntry *memmap = s->memmap;
+    AcpiTable table = { .sig = "DSDT", .rev = 2, .oem_id = s->oem_id,
+                        .oem_table_id = s->oem_table_id };
+
+
+    acpi_table_begin(&table, table_data);
+    dsdt = init_aml_allocator();
+
+    /*
+     * When booting the VM with UEFI, UEFI takes ownership of the RTC hardware.
+     * While UEFI can use libfdt to disable the RTC device node in the DTB that
+     * it passes to the OS, it cannot modify AML. Therefore, we won't generate
+     * the RTC ACPI device at all when using UEFI.
+     */
+    scope = aml_scope("\\_SB");
+    acpi_dsdt_add_cpus(scope, s);
+
+    acpi_dsdt_add_fw_cfg(scope, &memmap[VIRT_FW_CFG]);
+
+    aml_append(dsdt, scope);
+
+    /* copy AML table into ACPI tables blob and patch header there */
+    g_array_append_vals(table_data, dsdt->buf->data, dsdt->buf->len);
+
+    acpi_table_end(linker, &table);
+    free_aml_allocator();
+}
+
+static void virt_acpi_build(RISCVVirtState *s, AcpiBuildTables *tables)
+{
+    GArray *table_offsets;
+    unsigned dsdt, xsdt;
+    GArray *tables_blob = tables->table_data;
+
+    table_offsets = g_array_new(false, true,
+                                sizeof(uint32_t));
+
+    bios_linker_loader_alloc(tables->linker,
+                             ACPI_BUILD_TABLE_FILE, tables_blob,
+                             64, false);
+
+    /* DSDT is pointed to by FADT */
+    dsdt = tables_blob->len;
+    build_dsdt(tables_blob, tables->linker, s);
+
+    /* FADT and others pointed to by XSDT */
+    acpi_add_table(table_offsets, tables_blob);
+    build_fadt_rev6(tables_blob, tables->linker, s, dsdt);
+
+    /* XSDT is pointed to by RSDP */
+    xsdt = tables_blob->len;
+    build_xsdt(tables_blob, tables->linker, table_offsets, s->oem_id,
+                s->oem_table_id);
+
+    /* RSDP is in FSEG memory, so allocate it separately */
+    {
+        AcpiRsdpData rsdp_data = {
+            .revision = 2,
+            .oem_id = s->oem_id,
+            .xsdt_tbl_offset = &xsdt,
+            .rsdt_tbl_offset = NULL,
+        };
+        build_rsdp(tables->rsdp, tables->linker, &rsdp_data);
+    }
+
+    /*
+     * The align size is 128, warn if 64k is not enough therefore
+     * the align size could be resized.
+     */
+    if (tables_blob->len > ACPI_BUILD_TABLE_SIZE / 2) {
+        warn_report("ACPI table size %u exceeds %d bytes,"
+                    " migration may not work",
+                    tables_blob->len, ACPI_BUILD_TABLE_SIZE / 2);
+        error_printf("Try removing some objects.");
+    }
+    g_array_set_size(tables_blob, ROUND_UP(acpi_data_len(tables_blob),
+                     ACPI_BUILD_TABLE_SIZE));
+
+
+    /* Clean up memory that's no longer used */
+    g_array_free(table_offsets, true);
+}
+
+static void acpi_ram_update(MemoryRegion *mr, GArray *data)
+{
+    uint32_t size = acpi_data_len(data);
+
+    /*
+     * Make sure RAM size is correct - in case it got changed
+     * e.g. by migration
+     */
+    memory_region_ram_resize(mr, size, &error_abort);
+
+    memcpy(memory_region_get_ram_ptr(mr), data->data, size);
+    memory_region_set_dirty(mr, 0, size);
+}
+
+static void virt_acpi_build_update(void *build_opaque)
+{
+    AcpiBuildState *build_state = build_opaque;
+    AcpiBuildTables tables;
+
+    /* No state to update or already patched? Nothing to do. */
+    if (!build_state || build_state->patched) {
+        return;
+    }
+    build_state->patched = true;
+
+    acpi_build_tables_init(&tables);
+
+    virt_acpi_build(RISCV_VIRT_MACHINE(qdev_get_machine()), &tables);
+
+    acpi_ram_update(build_state->table_mr, tables.table_data);
+    acpi_ram_update(build_state->rsdp_mr, tables.rsdp);
+    acpi_ram_update(build_state->linker_mr, tables.linker->cmd_blob);
+
+    acpi_build_tables_cleanup(&tables, true);
+}
+
+static void virt_acpi_build_reset(void *build_opaque)
+{
+    AcpiBuildState *build_state = build_opaque;
+    build_state->patched = false;
+}
+
+static const VMStateDescription vmstate_virt_acpi_build = {
+    .name = "virt_acpi_build",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_BOOL(patched, AcpiBuildState),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+void virt_acpi_setup(RISCVVirtState *s)
+{
+    AcpiBuildTables tables;
+    AcpiBuildState *build_state;
+
+    build_state = g_malloc0(sizeof *build_state);
+
+    acpi_build_tables_init(&tables);
+    virt_acpi_build(s, &tables);
+
+    /* Now expose it all to Guest */
+    build_state->table_mr = acpi_add_rom_blob(virt_acpi_build_update,
+                                              build_state, tables.table_data,
+                                              ACPI_BUILD_TABLE_FILE);
+    assert(build_state->table_mr != NULL);
+
+    build_state->linker_mr = acpi_add_rom_blob(virt_acpi_build_update,
+                                               build_state,
+                                               tables.linker->cmd_blob,
+                                               ACPI_BUILD_LOADER_FILE);
+
+    build_state->rsdp_mr = acpi_add_rom_blob(virt_acpi_build_update,
+                                             build_state, tables.rsdp,
+                                             ACPI_BUILD_RSDP_FILE);
+
+    qemu_register_reset(virt_acpi_build_reset, build_state);
+    virt_acpi_build_reset(build_state);
+    vmstate_register(NULL, 0, &vmstate_virt_acpi_build, build_state);
+
+    /*
+     * Clean up tables but don't free the memory: we track it
+     * in build_state.
+     */
+    acpi_build_tables_cleanup(&tables, false);
+}
diff --git a/include/hw/riscv/virt.h b/include/hw/riscv/virt.h
index 379501edcc..e5c474b26e 100644
--- a/include/hw/riscv/virt.h
+++ b/include/hw/riscv/virt.h
@@ -126,4 +126,5 @@ enum {
                                  1 + FDT_APLIC_INT_CELLS)
 
 bool virt_is_acpi_enabled(RISCVVirtState *s);
+void virt_acpi_setup(RISCVVirtState *vms);
 #endif
-- 
2.34.1