Re: [PATCH v3 2/2] hw/mips/loongson3_virt: Add TCG SMP support

[Huacai Chen]

Hi, Jiaxun,

On Mon, Jan 18, 2021 at 9:17 AM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>
> loongson3_virt has KVM SMP support in kenrel.
s/kenrel/kernel/g

Huacai
> This patch adds TCG SMP support by enable IPI controller
> for machine.
>
> Also add definition about IRQs to enhance readability.
>
> Note that TCG SMP can only support up to 4 CPUs as we
> didn't implement multi-node support.
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  hw/mips/loongson3_bootp.h |  1 +
>  hw/mips/loongson3_virt.c  | 41 ++++++++++++++++++++++++++++++++-------
>  hw/mips/Kconfig           |  1 +
>  3 files changed, 36 insertions(+), 7 deletions(-)
>
> diff --git a/hw/mips/loongson3_bootp.h b/hw/mips/loongson3_bootp.h
> index 09f8480abf..4756aa44f6 100644
> --- a/hw/mips/loongson3_bootp.h
> +++ b/hw/mips/loongson3_bootp.h
> @@ -210,6 +210,7 @@ enum {
>      VIRT_PCIE_ECAM,
>      VIRT_BIOS_ROM,
>      VIRT_UART,
> +    VIRT_IPIS,
>      VIRT_LIOINTC,
>      VIRT_PCIE_MMIO,
>      VIRT_HIGHMEM
> diff --git a/hw/mips/loongson3_virt.c b/hw/mips/loongson3_virt.c
> index d4a82fa536..0765addb7f 100644
> --- a/hw/mips/loongson3_virt.c
> +++ b/hw/mips/loongson3_virt.c
> @@ -35,6 +35,7 @@
>  #include "hw/boards.h"
>  #include "hw/char/serial.h"
>  #include "hw/intc/loongson_liointc.h"
> +#include "hw/intc/loongson_ipi.h"
>  #include "hw/mips/mips.h"
>  #include "hw/mips/cpudevs.h"
>  #include "hw/mips/fw_cfg.h"
> @@ -59,7 +60,11 @@
>
>  #define PM_CNTL_MODE          0x10
>
> -#define LOONGSON_MAX_VCPUS      16
> +#define VCPU_PER_NODE         4
> +#define TCG_MAX_NODES         1
> +#define KVM_MAX_NODES         4
> +#define TCG_MAX_VCPUS         (TCG_MAX_NODES  * VCPU_PER_NODE)
> +#define KVM_MAX_VCPUS         (KVM_MAX_NODES  * VCPU_PER_NODE)
>
>  /*
>   * Loongson-3's virtual machine BIOS can be obtained here:
> @@ -68,9 +73,16 @@
>   */
>  #define LOONGSON3_BIOSNAME "bios_loongson3.bin"
>
> +/* IRQ allocation of CPU IP */
> +#define LIOINTC_IP_START    2
> +#define LIOINTC_IP_END      5
> +#define IPI_IP              6
> +
> +/* IRQ allcation of LIOINTC */
>  #define UART_IRQ            0
>  #define RTC_IRQ             1
>  #define PCIE_IRQ_BASE       2
> +#define IPI_REG_SPACE       0x100
>
>  const struct MemmapEntry virt_memmap[] = {
>      [VIRT_LOWMEM] =      { 0x00000000,    0x10000000 },
> @@ -81,6 +93,7 @@ const struct MemmapEntry virt_memmap[] = {
>      [VIRT_PCIE_ECAM] =   { 0x1a000000,     0x2000000 },
>      [VIRT_BIOS_ROM] =    { 0x1fc00000,      0x200000 },
>      [VIRT_UART] =        { 0x1fe001e0,           0x8 },
> +    [VIRT_IPIS] =        { 0x3ff01000,         0x400 },
>      [VIRT_LIOINTC] =     { 0x3ff01400,          0x64 },
>      [VIRT_PCIE_MMIO] =   { 0x40000000,    0x40000000 },
>      [VIRT_HIGHMEM] =     { 0x80000000,           0x0 }, /* Variable */
> @@ -495,6 +508,10 @@ static void mips_loongson3_virt_init(MachineState 
> *machine)
>              error_report("Loongson-3/TCG needs cpu type Loongson-3A1000");
>              exit(1);
>          }
> +        if (machine->smp.cpus > TCG_MAX_VCPUS) {
> +            error_report("Loongson-3/TCG supports up to %d CPUs", 
> TCG_MAX_VCPUS);
> +            exit(1);
> +        }
>      } else {
>          if (!machine->cpu_type) {
>              machine->cpu_type = MIPS_CPU_TYPE_NAME("Loongson-3A4000");
> @@ -544,14 +561,24 @@ static void mips_loongson3_virt_init(MachineState 
> *machine)
>          cpu_mips_clock_init(cpu);
>          qemu_register_reset(main_cpu_reset, cpu);
>
> -        if (i >= 4) {
> -            continue; /* Only node-0 can be connected to LIOINTC */
> +        if (i >= VCPU_PER_NODE) {
> +            continue; /* Only node-0 can be connected to LIOINTC and IPI */
> +        }
> +
> +        if (!kvm_enabled()) {
> +            /* IPI is handled by kernel for KVM */
> +            DeviceState *ipi;
> +            ipi = qdev_new(TYPE_LOONGSON_IPI);
> +            sysbus_realize_and_unref(SYS_BUS_DEVICE(ipi), &error_fatal);
> +            sysbus_mmio_map(SYS_BUS_DEVICE(ipi), 0,
> +                            virt_memmap[VIRT_IPIS].base + IPI_REG_SPACE * i);
> +            sysbus_connect_irq(SYS_BUS_DEVICE(ipi), 0, cpu->env.irq[IPI_IP]);
>          }
>
> -        for (ip = 0; ip < 4 ; ip++) {
> -            int pin = i * 4 + ip;
> +        for (ip = LIOINTC_IP_START; ip <= LIOINTC_IP_END ; ip++) {
> +            int pin = i * 4 + (ip - LIOINTC_IP_START);
>              sysbus_connect_irq(SYS_BUS_DEVICE(liointc),
> -                               pin, cpu->env.irq[ip + 2]);
> +                               pin, cpu->env.irq[ip]);
>          }
>      }
>      env = &MIPS_CPU(first_cpu)->env;
> @@ -619,7 +646,7 @@ static void loongson3v_machine_class_init(ObjectClass 
> *oc, void *data)
>      mc->desc = "Loongson-3 Virtualization Platform";
>      mc->init = mips_loongson3_virt_init;
>      mc->block_default_type = IF_IDE;
> -    mc->max_cpus = LOONGSON_MAX_VCPUS;
> +    mc->max_cpus = KVM_MAX_VCPUS;
>      mc->default_ram_id = "loongson3.highram";
>      mc->default_ram_size = 1600 * MiB;
>      mc->kvm_type = mips_kvm_type;
> diff --git a/hw/mips/Kconfig b/hw/mips/Kconfig
> index aadd436bf4..4fb0cc49e8 100644
> --- a/hw/mips/Kconfig
> +++ b/hw/mips/Kconfig
> @@ -39,6 +39,7 @@ config LOONGSON3V
>      select SERIAL
>      select GOLDFISH_RTC
>      select LOONGSON_LIOINTC
> +    select LOONGSON_IPI if TCG
>      select PCI_DEVICES
>      select PCI_EXPRESS_GENERIC_BRIDGE
>      select MSI_NONBROKEN
> --
> 2.30.0
>