Re: [PATCH v4 2/6] target/riscv: support the AIA device emulation with KVM enabled

[Andrew Jones]

On Wed, Jun 21, 2023 at 02:54:52PM +0000, Yong-Xuan Wang wrote:
> Remove M mode AIA devices when using KVM acceleration
> 
> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
> Reviewed-by: Jim Shu <jim.shu@sifive.com>
> ---
>  hw/riscv/virt.c | 207 +++++++++++++++++++++++++-----------------------
>  1 file changed, 108 insertions(+), 99 deletions(-)
> 
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 245c7b97b2..4a1d29a741 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -531,52 +531,54 @@ static void create_fdt_imsic(RISCVVirtState *s, const 
> MemMapEntry *memmap,
>      imsic_cells = g_new0(uint32_t, ms->smp.cpus * 2);
>      imsic_regs = g_new0(uint32_t, socket_count * 4);
>  
> -    /* M-level IMSIC node */
> -    for (cpu = 0; cpu < ms->smp.cpus; cpu++) {
> -        imsic_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
> -        imsic_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_M_EXT);
> -    }
> -    imsic_max_hart_per_socket = 0;
> -    for (socket = 0; socket < socket_count; socket++) {
> -        imsic_addr = memmap[VIRT_IMSIC_M].base +
> -                     socket * VIRT_IMSIC_GROUP_MAX_SIZE;
> -        imsic_size = IMSIC_HART_SIZE(0) * s->soc[socket].num_harts;
> -        imsic_regs[socket * 4 + 0] = 0;
> -        imsic_regs[socket * 4 + 1] = cpu_to_be32(imsic_addr);
> -        imsic_regs[socket * 4 + 2] = 0;
> -        imsic_regs[socket * 4 + 3] = cpu_to_be32(imsic_size);
> -        if (imsic_max_hart_per_socket < s->soc[socket].num_harts) {
> -            imsic_max_hart_per_socket = s->soc[socket].num_harts;
> +    if (!kvm_enabled()) {
> +        /* M-level IMSIC node */
> +        for (cpu = 0; cpu < ms->smp.cpus; cpu++) {
> +            imsic_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
> +            imsic_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_M_EXT);
>          }
> -    }
> -    imsic_name = g_strdup_printf("/soc/imsics@%lx",
> -        (unsigned long)memmap[VIRT_IMSIC_M].base);
> -    qemu_fdt_add_subnode(ms->fdt, imsic_name);
> -    qemu_fdt_setprop_string(ms->fdt, imsic_name, "compatible",
> -        "riscv,imsics");
> -    qemu_fdt_setprop_cell(ms->fdt, imsic_name, "#interrupt-cells",
> -        FDT_IMSIC_INT_CELLS);
> -    qemu_fdt_setprop(ms->fdt, imsic_name, "interrupt-controller",
> -        NULL, 0);
> -    qemu_fdt_setprop(ms->fdt, imsic_name, "msi-controller",
> -        NULL, 0);
> -    qemu_fdt_setprop(ms->fdt, imsic_name, "interrupts-extended",
> -        imsic_cells, ms->smp.cpus * sizeof(uint32_t) * 2);
> -    qemu_fdt_setprop(ms->fdt, imsic_name, "reg", imsic_regs,
> -        socket_count * sizeof(uint32_t) * 4);
> -    qemu_fdt_setprop_cell(ms->fdt, imsic_name, "riscv,num-ids",
> -        VIRT_IRQCHIP_NUM_MSIS);
> -    if (socket_count > 1) {
> -        qemu_fdt_setprop_cell(ms->fdt, imsic_name, "riscv,hart-index-bits",
> -            imsic_num_bits(imsic_max_hart_per_socket));
> -        qemu_fdt_setprop_cell(ms->fdt, imsic_name, "riscv,group-index-bits",
> -            imsic_num_bits(socket_count));
> -        qemu_fdt_setprop_cell(ms->fdt, imsic_name, "riscv,group-index-shift",
> -            IMSIC_MMIO_GROUP_MIN_SHIFT);
> -    }
> -    qemu_fdt_setprop_cell(ms->fdt, imsic_name, "phandle", *msi_m_phandle);
> +        imsic_max_hart_per_socket = 0;
> +        for (socket = 0; socket < socket_count; socket++) {
> +            imsic_addr = memmap[VIRT_IMSIC_M].base +
> +                         socket * VIRT_IMSIC_GROUP_MAX_SIZE;
> +            imsic_size = IMSIC_HART_SIZE(0) * s->soc[socket].num_harts;
> +            imsic_regs[socket * 4 + 0] = 0;
> +            imsic_regs[socket * 4 + 1] = cpu_to_be32(imsic_addr);
> +            imsic_regs[socket * 4 + 2] = 0;
> +            imsic_regs[socket * 4 + 3] = cpu_to_be32(imsic_size);
> +            if (imsic_max_hart_per_socket < s->soc[socket].num_harts) {
> +                imsic_max_hart_per_socket = s->soc[socket].num_harts;
> +            }
> +        }
> +        imsic_name = g_strdup_printf("/soc/imsics@%lx",
> +            (unsigned long)memmap[VIRT_IMSIC_M].base);
> +        qemu_fdt_add_subnode(ms->fdt, imsic_name);
> +        qemu_fdt_setprop_string(ms->fdt, imsic_name, "compatible",
> +            "riscv,imsics");
> +        qemu_fdt_setprop_cell(ms->fdt, imsic_name, "#interrupt-cells",
> +            FDT_IMSIC_INT_CELLS);
> +        qemu_fdt_setprop(ms->fdt, imsic_name, "interrupt-controller",
> +            NULL, 0);
> +        qemu_fdt_setprop(ms->fdt, imsic_name, "msi-controller",
> +            NULL, 0);
> +        qemu_fdt_setprop(ms->fdt, imsic_name, "interrupts-extended",
> +            imsic_cells, ms->smp.cpus * sizeof(uint32_t) * 2);
> +        qemu_fdt_setprop(ms->fdt, imsic_name, "reg", imsic_regs,
> +            socket_count * sizeof(uint32_t) * 4);
> +        qemu_fdt_setprop_cell(ms->fdt, imsic_name, "riscv,num-ids",
> +            VIRT_IRQCHIP_NUM_MSIS);
> +        if (socket_count > 1) {
> +            qemu_fdt_setprop_cell(ms->fdt, imsic_name, 
> "riscv,hart-index-bits",
> +                imsic_num_bits(imsic_max_hart_per_socket));
> +            qemu_fdt_setprop_cell(ms->fdt, imsic_name, 
> "riscv,group-index-bits",
> +                imsic_num_bits(socket_count));
> +            qemu_fdt_setprop_cell(ms->fdt, imsic_name,
> +                "riscv,group-index-shift", IMSIC_MMIO_GROUP_MIN_SHIFT);
> +        }
> +        qemu_fdt_setprop_cell(ms->fdt, imsic_name, "phandle", 
> *msi_m_phandle);
>  
> -    g_free(imsic_name);
> +        g_free(imsic_name);
> +    }

The create_fdt_imsic() code for M-mode and S-mode is nearly identical. I
suggest creating a helper function where the differences have been
parameterized so we can write this something like

  void create_fdt_imsic(...)
  {
     if (!kvm_enabled()) {
         create_fdt_one_imsic(VIRT_IMSIC_M, 0, ...);
     }
     
     create_fdt_one_imsic(VIRT_IMSIC_S, imsic_num_bits(s->aia_guests + 1), ...);
  }

>  
>      /* S-level IMSIC node */
>      for (cpu = 0; cpu < ms->smp.cpus; cpu++) {
> @@ -653,37 +655,40 @@ static void create_fdt_socket_aplic(RISCVVirtState *s,
>      aplic_s_phandle = (*phandle)++;
>      aplic_cells = g_new0(uint32_t, s->soc[socket].num_harts * 2);
>  
> -    /* M-level APLIC node */
> -    for (cpu = 0; cpu < s->soc[socket].num_harts; cpu++) {
> -        aplic_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
> -        aplic_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_M_EXT);
> -    }
> -    aplic_addr = memmap[VIRT_APLIC_M].base +
> -                 (memmap[VIRT_APLIC_M].size * socket);
> -    aplic_name = g_strdup_printf("/soc/aplic@%lx", aplic_addr);
> -    qemu_fdt_add_subnode(ms->fdt, aplic_name);
> -    qemu_fdt_setprop_string(ms->fdt, aplic_name, "compatible", 
> "riscv,aplic");
> -    qemu_fdt_setprop_cell(ms->fdt, aplic_name,
> -        "#interrupt-cells", FDT_APLIC_INT_CELLS);
> -    qemu_fdt_setprop(ms->fdt, aplic_name, "interrupt-controller", NULL, 0);
> -    if (s->aia_type == VIRT_AIA_TYPE_APLIC) {
> -        qemu_fdt_setprop(ms->fdt, aplic_name, "interrupts-extended",
> -            aplic_cells, s->soc[socket].num_harts * sizeof(uint32_t) * 2);
> -    } else {
> -        qemu_fdt_setprop_cell(ms->fdt, aplic_name, "msi-parent",
> -            msi_m_phandle);
> +    if (!kvm_enabled()) {
> +        /* M-level APLIC node */
> +        for (cpu = 0; cpu < s->soc[socket].num_harts; cpu++) {
> +            aplic_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
> +            aplic_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_M_EXT);
> +        }
> +        aplic_addr = memmap[VIRT_APLIC_M].base +
> +                     (memmap[VIRT_APLIC_M].size * socket);
> +        aplic_name = g_strdup_printf("/soc/aplic@%lx", aplic_addr);
> +        qemu_fdt_add_subnode(ms->fdt, aplic_name);
> +        qemu_fdt_setprop_string(ms->fdt, aplic_name,
> +            "compatible", "riscv,aplic");
> +        qemu_fdt_setprop_cell(ms->fdt, aplic_name,
> +            "#interrupt-cells", FDT_APLIC_INT_CELLS);
> +        qemu_fdt_setprop(ms->fdt, aplic_name, "interrupt-controller", NULL, 
> 0);
> +        if (s->aia_type == VIRT_AIA_TYPE_APLIC) {
> +            qemu_fdt_setprop(ms->fdt, aplic_name, "interrupts-extended",
> +                aplic_cells, s->soc[socket].num_harts * sizeof(uint32_t) * 
> 2);
> +        } else {
> +            qemu_fdt_setprop_cell(ms->fdt, aplic_name, "msi-parent",
> +                msi_m_phandle);
> +        }
> +        qemu_fdt_setprop_cells(ms->fdt, aplic_name, "reg",
> +            0x0, aplic_addr, 0x0, memmap[VIRT_APLIC_M].size);
> +        qemu_fdt_setprop_cell(ms->fdt, aplic_name, "riscv,num-sources",
> +            VIRT_IRQCHIP_NUM_SOURCES);
> +        qemu_fdt_setprop_cell(ms->fdt, aplic_name, "riscv,children",
> +            aplic_s_phandle);
> +        qemu_fdt_setprop_cells(ms->fdt, aplic_name, "riscv,delegate",
> +            aplic_s_phandle, 0x1, VIRT_IRQCHIP_NUM_SOURCES);
> +        riscv_socket_fdt_write_id(ms, aplic_name, socket);
> +        qemu_fdt_setprop_cell(ms->fdt, aplic_name, "phandle", 
> aplic_m_phandle);
> +        g_free(aplic_name);
>      }
> -    qemu_fdt_setprop_cells(ms->fdt, aplic_name, "reg",
> -        0x0, aplic_addr, 0x0, memmap[VIRT_APLIC_M].size);
> -    qemu_fdt_setprop_cell(ms->fdt, aplic_name, "riscv,num-sources",
> -        VIRT_IRQCHIP_NUM_SOURCES);
> -    qemu_fdt_setprop_cell(ms->fdt, aplic_name, "riscv,children",
> -        aplic_s_phandle);
> -    qemu_fdt_setprop_cells(ms->fdt, aplic_name, "riscv,delegate",
> -        aplic_s_phandle, 0x1, VIRT_IRQCHIP_NUM_SOURCES);
> -    riscv_socket_fdt_write_id(ms, aplic_name, socket);
> -    qemu_fdt_setprop_cell(ms->fdt, aplic_name, "phandle", aplic_m_phandle);
> -    g_free(aplic_name);

I think it should be possible to parameterize an aplic helper as well.

>  
>      /* S-level APLIC node */
>      for (cpu = 0; cpu < s->soc[socket].num_harts; cpu++) {
> @@ -1162,16 +1167,20 @@ static DeviceState *virt_create_aia(RISCVVirtAIAType 
> aia_type, int aia_guests,
>      int i;
>      hwaddr addr;
>      uint32_t guest_bits;
> -    DeviceState *aplic_m;
> +    DeviceState *aplic_s = NULL;
> +    DeviceState *aplic_m = NULL;
>      bool msimode = (aia_type == VIRT_AIA_TYPE_APLIC_IMSIC) ? true : false;

Not introduced with this patch, but we should drop the unnecessary () and
'? true : false' on this line.

>  
>      if (msimode) {
> -        /* Per-socket M-level IMSICs */
> -        addr = memmap[VIRT_IMSIC_M].base + socket * 
> VIRT_IMSIC_GROUP_MAX_SIZE;
> -        for (i = 0; i < hart_count; i++) {
> -            riscv_imsic_create(addr + i * IMSIC_HART_SIZE(0),
> -                               base_hartid + i, true, 1,
> -                               VIRT_IRQCHIP_NUM_MSIS);
> +        if (!kvm_enabled()) {
> +            /* Per-socket M-level IMSICs */
> +            addr = memmap[VIRT_IMSIC_M].base +
> +                   socket * VIRT_IMSIC_GROUP_MAX_SIZE;
> +            for (i = 0; i < hart_count; i++) {
> +                riscv_imsic_create(addr + i * IMSIC_HART_SIZE(0),
> +                        base_hartid + i, true, 1,
> +                        VIRT_IRQCHIP_NUM_MSIS);
> +            }
>          }
>  
>          /* Per-socket S-level IMSICs */
> @@ -1184,29 +1193,29 @@ static DeviceState *virt_create_aia(RISCVVirtAIAType 
> aia_type, int aia_guests,
>          }
>      }
>  
> -    /* Per-socket M-level APLIC */
> -    aplic_m = riscv_aplic_create(
> -        memmap[VIRT_APLIC_M].base + socket * memmap[VIRT_APLIC_M].size,
> -        memmap[VIRT_APLIC_M].size,
> +    if (!kvm_enabled()) {
> +        /* Per-socket M-level APLIC */
> +        aplic_m = riscv_aplic_create(
> +                memmap[VIRT_APLIC_M].base + socket * 
> memmap[VIRT_APLIC_M].size,
> +                memmap[VIRT_APLIC_M].size,
> +                (msimode) ? 0 : base_hartid,
> +                (msimode) ? 0 : hart_count,
> +                VIRT_IRQCHIP_NUM_SOURCES,
> +                VIRT_IRQCHIP_NUM_PRIO_BITS,
> +                msimode, true, NULL);
> +    }
> +
> +    /* Per-socket S-level APLIC */
> +    aplic_s = riscv_aplic_create(
> +        memmap[VIRT_APLIC_S].base + socket * memmap[VIRT_APLIC_S].size,
> +        memmap[VIRT_APLIC_S].size,
>          (msimode) ? 0 : base_hartid,
>          (msimode) ? 0 : hart_count,
>          VIRT_IRQCHIP_NUM_SOURCES,
>          VIRT_IRQCHIP_NUM_PRIO_BITS,
> -        msimode, true, NULL);
> -
> -    if (aplic_m) {
> -        /* Per-socket S-level APLIC */
> -        riscv_aplic_create(
> -            memmap[VIRT_APLIC_S].base + socket * memmap[VIRT_APLIC_S].size,
> -            memmap[VIRT_APLIC_S].size,
> -            (msimode) ? 0 : base_hartid,
> -            (msimode) ? 0 : hart_count,
> -            VIRT_IRQCHIP_NUM_SOURCES,
> -            VIRT_IRQCHIP_NUM_PRIO_BITS,
> -            msimode, false, aplic_m);
> -    }
> +        msimode, false, aplic_m);
>  
> -    return aplic_m;
> +    return kvm_enabled() ? aplic_s : aplic_m;
>  }
>  
>  static void create_platform_bus(RISCVVirtState *s, DeviceState *irqchip)
> -- 
> 2.17.1
> 
>

Thanks,
drew