Re: [PATCH v3 04/10] hw/riscv/virt: add opt-in RPMI base support

Daniel,

On Fri, Jul 17, 2026 at 6:47 PM Daniel Henrique Barboza
<[email protected]> wrote:
>
>
>
> On 7/14/2026 4:56 AM, Subrahmanya Lingappa wrote:
> > Add the virt machine rpmi=on/off option and wire the initial RPMI Base
> > transport into machine realization.
> >
> > The option remains disabled by default and requires TCG plus librpmi.
> > Invalid accelerator/build combinations fail during machine
> > initialization. When enabled, virt allocates the RPMI shared-memory
> > transport, creates the RPMI device, configures Base service metadata,
> > and emits the corresponding device-tree nodes for firmware discovery.
> >
> > Signed-off-by: Subrahmanya Lingappa <[email protected]>
> > ---
> >   hw/riscv/Kconfig             |  1 +
> >   hw/riscv/virt.c              | 96 ++++++++++++++++++++++++++++++++++++
> >   include/hw/misc/riscv_rpmi.h | 10 ++++
> >   include/hw/riscv/virt.h      |  3 ++
> >   4 files changed, 110 insertions(+)
> >
> > diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
> > index 54e41a6afc..4e25be113a 100644
> > --- a/hw/riscv/Kconfig
> > +++ b/hw/riscv/Kconfig
> > @@ -49,6 +49,7 @@ config RISCV_VIRT
> >       imply VIRTIO_VGA
> >       imply TEST_DEVICES
> >       imply TPM_TIS_SYSBUS
> > +    imply RISCV_RPMI
> >       select DEVICE_TREE
> >       select RISCV_NUMA
> >       select GOLDFISH_RTC
> > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> > index 33775a61fd..e52ccfae1f 100644
> > --- a/hw/riscv/virt.c
> > +++ b/hw/riscv/virt.c
> > @@ -45,6 +45,8 @@
> >   #include "hw/intc/riscv_aplic.h"
> >   #include "hw/intc/sifive_plic.h"
> >   #include "hw/misc/sifive_test.h"
> > +#include "hw/misc/riscv_rpmi.h"
> > +#include "hw/riscv/rpmi-fdt.h"
> >   #include "hw/core/platform-bus.h"
> >   #include "chardev/char.h"
> >   #include "system/device_tree.h"
> > @@ -97,6 +99,8 @@ static const MemMapEntry virt_memmap[] = {
> >       [VIRT_UART0] =        { 0x10000000,         0x100 },
> >       [VIRT_VIRTIO] =       { 0x10001000,        0x1000 },
> >       [VIRT_FW_CFG] =       { 0x10100000,          0x18 },
> > +    [VIRT_RPMI_SHMEM] =   { 0x10200000,       0x20000 },
> > +    [VIRT_RPMI_DOORBELL] = { 0x10230000,        0x1000 },
> >       [VIRT_FLASH] =        { 0x20000000,     0x4000000 },
> >       [VIRT_IMSIC_M] =      { 0x24000000, VIRT_IMSIC_MAX_SIZE },
> >       [VIRT_IMSIC_S] =      { 0x28000000, VIRT_IMSIC_MAX_SIZE },
> > @@ -1002,6 +1006,40 @@ static void create_fdt_iommu(RISCVVirtState *s, uint16_t bdf)
> >       s->pci_iommu_bdf = bdf;
> >   }
> >
> > +
> > +static RiscvRpmiConfig virt_rpmi_config(RISCVVirtState *s,
> > +                                        const uint32_t *hart_ids,
> > +                                        uint32_t hart_count)
> > +{
> > +    return (RiscvRpmiConfig) {
> > +        .doorbell_base = s->memmap[VIRT_RPMI_DOORBELL].base,
> > +        .shmem_base = s->memmap[VIRT_RPMI_SHMEM].base,
> > +        .shmem_size = s->memmap[VIRT_RPMI_SHMEM].size,
> > +        .a2p_req_size = VIRT_RPMI_A2P_REQ_SIZE,
> > +        .p2a_req_size = VIRT_RPMI_P2A_REQ_SIZE,
> > +        .platform_info = "QEMU RISC-V virt RPMI",
> > +        .hart_ids = hart_ids,
> > +        .hart_count = hart_count,
> > +    };
> > +}
> > +
> > +static void create_fdt_rpmi(RISCVVirtState *s, uint32_t *phandle,
> > +                            uint32_t msi_phandle)
> > +{
> > +    RiscvRpmiConfig rpmi_cfg = virt_rpmi_config(s, NULL, 0);
> > +    uint32_t rpmi_mbox_handle;
> > +    RiscvRpmiFdtMboxConfig cfg = {
> > +        .shmem_base = rpmi_cfg.shmem_base,
> > +        .doorbell_base = rpmi_cfg.doorbell_base,
> > +        .a2p_req_size = rpmi_cfg.a2p_req_size,
> > +        .p2a_req_size = rpmi_cfg.p2a_req_size,
> > +        .doorbell_size = s->memmap[VIRT_RPMI_DOORBELL].size,
> > +    };
> > +
> > +    riscv_rpmi_fdt_add_mbox(MACHINE(s)->fdt, &cfg, phandle,
> > +                            &rpmi_mbox_handle);
> > +}
> > +
> >   static void finalize_fdt(RISCVVirtState *s)
> >   {
> >       uint32_t phandle = 1, irq_mmio_phandle = 1, msi_pcie_phandle = 1;
> > @@ -1021,6 +1059,10 @@ static void finalize_fdt(RISCVVirtState *s)
> >       create_fdt_pcie(s, irq_pcie_phandle, msi_pcie_phandle,
> >                       iommu_sys_phandle);
> >
> > +    if (s->have_rpmi) {
> > +        create_fdt_rpmi(s, &phandle, msi_pcie_phandle);
> > +    }
> > +
> >       create_fdt_reset(s, &phandle);
> >
> >       create_fdt_uart(s, irq_mmio_phandle);
> > @@ -1410,6 +1452,18 @@ static void virt_machine_init(MachineState *machine)
> >           exit(1);
> >       }
> >
> > +
> > +    if (s->have_rpmi) {
> > +#ifndef CONFIG_LIBRPMI
> > +        error_report("RISC-V RPMI support is not compiled in");
> > +        exit(1);
> > +#else
> > +        if (kvm_enabled()) {
> > +            error_report("RISC-V RPMI support is not available with KVM");
> > +            exit(1);
> > +        }
> > +#endif
> > +    }
> >       /* Initialize sockets */
> >       mmio_irqchip = virtio_irqchip = pcie_irqchip = NULL;
> >       for (i = 0; i < socket_count; i++) {
> > @@ -1552,6 +1606,25 @@ static void virt_machine_init(MachineState *machine)
> >       /* SiFive Test MMIO device */
> >       sifive_test_create(s->memmap[VIRT_TEST].base);
> >
> > +    if (s->have_rpmi) {
> > +        MachineClass *mc = MACHINE_GET_CLASS(machine);
> > +        const CPUArchIdList *possible_cpus = mc->possible_cpu_arch_ids(machine);
> > +        g_autofree uint32_t *rpmi_hart_ids =
> > +            g_new0(uint32_t, machine->smp.cpus);
> > +        RiscvRpmiConfig rpmi_cfg;
> > +        Error *local_err = NULL;
> > +
> > +        for (i = 0; i < machine->smp.cpus; i++) {
> > +            rpmi_hart_ids[i] = possible_cpus->cpus[i].arch_id;
> > +        }
> > +
> > +        rpmi_cfg = virt_rpmi_config(s, rpmi_hart_ids, machine->smp.cpus);
> > +        if (!riscv_rpmi_create(&rpmi_cfg, &local_err)) {
> > +            error_report_err(local_err);
> > +            exit(1);
> > +        }
> > +    }
> > +
> >       /* VirtIO MMIO devices */
> >       for (i = 0; i < VIRTIO_COUNT; i++) {
> >           sysbus_create_simple("virtio-mmio",
> > @@ -1636,6 +1709,7 @@ static void virt_machine_instance_init(Object *obj)
> >
> >       s->oem_id = g_strndup(ACPI_BUILD_APPNAME6, 6);
> >       s->oem_table_id = g_strndup(ACPI_BUILD_APPNAME8, 8);
> > +    s->have_rpmi = false;
> >       s->acpi = ON_OFF_AUTO_AUTO;
> >       s->iommu_sys = ON_OFF_AUTO_AUTO;
> >   }
> > @@ -1710,6 +1784,21 @@ static void virt_set_aclint(Object *obj, bool value, Error **errp)
> >       s->have_aclint = value;
> >   }
> >
> > +
> > +static bool virt_get_rpmi(Object *obj, Error **errp)
> > +{
> > +    RISCVVirtState *s = RISCV_VIRT_MACHINE(obj);
> > +
> > +    return s->have_rpmi;
> > +}
> > +
> > +static void virt_set_rpmi(Object *obj, bool value, Error **errp)
> > +{
> > +    RISCVVirtState *s = RISCV_VIRT_MACHINE(obj);
> > +
> > +    s->have_rpmi = value;
> > +}
> > +
> >   bool virt_is_iommu_sys_enabled(RISCVVirtState *s)
> >   {
> >       return s->iommu_sys == ON_OFF_AUTO_ON;
> > @@ -1831,6 +1920,13 @@ static void virt_machine_class_init(ObjectClass *oc, const void *data)
> >                                             "enable/disable emulating "
> >                                             "ACLINT devices");
> >
> > +
> > +    object_class_property_add_bool(oc, "rpmi", virt_get_rpmi,
> > +                                   virt_set_rpmi);
> > +    object_class_property_set_description(oc, "rpmi",
> > +                                          "Set on/off to enable/disable "
> > +                                          "RISC-V RPMI devices");
> > +
> >       object_class_property_add_str(oc, "aia", virt_get_aia,
> >                                     virt_set_aia);
> >       object_class_property_set_description(oc, "aia",
> > diff --git a/include/hw/misc/riscv_rpmi.h b/include/hw/misc/riscv_rpmi.h
> > index cb2658e57e..b5d8a32f9b 100644
> > --- a/include/hw/misc/riscv_rpmi.h
> > +++ b/include/hw/misc/riscv_rpmi.h
> > @@ -85,6 +85,16 @@ struct RiscvRpmiState {
> >       bool has_shmem;
> >   };
> >
> > +#ifdef CONFIG_LIBRPMI
> >   DeviceState *riscv_rpmi_create(const RiscvRpmiConfig *cfg, Error **errp);
> > +#else
> > +static inline DeviceState *riscv_rpmi_create(const RiscvRpmiConfig *cfg,
> > +                                             Error **errp)
> > +{
> > +    (void)cfg;
> > +    (void)errp;
> > +    return NULL;
> > +}
>
> I think you can do:
>
> static inline DeviceState *riscv_rpmi_create(const RiscvRpmiConfig *cfg G_GNUC_UNUSED,
>                                               Error **errp G_GNUC_UNUSED)
> {
>      return NULL;
> }
>
> Instead of using the args as void to not get warnings.
>
>
> Everything else LGTM.  Thanks,
> Daniel
>
  Fixed in v4. I replaced the explicit unused-parameter casts in the
  no-librpmi inline stub with G_GNUC_UNUSED.

Thanks,
Subbu

>
> > +#endif
> >
> >   #endif
> > diff --git a/include/hw/riscv/virt.h b/include/hw/riscv/virt.h
> > index 18a2a323a3..f7c48613bf 100644
> > --- a/include/hw/riscv/virt.h
> > +++ b/include/hw/riscv/virt.h
> > @@ -55,6 +55,7 @@ struct RISCVVirtState {
> >
> >       int fdt_size;
> >       bool have_aclint;
> > +    bool have_rpmi;
> >       RISCVVirtAIAType aia_type;
> >       int aia_guests;
> >       char *oem_id;
> > @@ -79,6 +80,8 @@ enum {
> >       VIRT_UART0,
> >       VIRT_VIRTIO,
> >       VIRT_FW_CFG,
> > +    VIRT_RPMI_SHMEM,
> > +    VIRT_RPMI_DOORBELL,
> >       VIRT_IMSIC_M,
> >       VIRT_IMSIC_S,
> >       VIRT_FLASH,
>