Re: [PATCH 0/9] Linux RISC-V AIA Support

From: Anup Patel
Date: Mon Jan 02 2023 - 05:05:41 EST


On Fri, Nov 11, 2022 at 2:37 PM Atish Patra <atishp@xxxxxxxxxxxxxx> wrote:
>
> On Thu, Nov 10, 2022 at 8:42 PM Anup Patel <apatel@xxxxxxxxxxxxxxxx> wrote:
> >
> > The RISC-V AIA specification is now frozen as-per the RISC-V international
> > process. The latest frozen specifcation can be found at:
> > https://github.com/riscv/riscv-aia/releases/download/1.0-RC1/riscv-interrupts-1.0-RC1.pdf
> >
> > At a high-level, the AIA specification adds three things:
> > 1) AIA CSRs
> > - Improved local interrupt support
> > 2) Incoming Message Signaled Interrupt Controller (IMSIC)
> > - Per-HART MSI controller
> > - Support MSI virtualization
> > - Support IPI along with virtualization
> > 3) Advanced Platform-Level Interrupt Controller (APLIC)
> > - Wired interrupt controller
> > - In MSI-mode, converts wired interrupt into MSIs (i.e. MSI generator)
> > - In Direct-mode, injects external interrupts directly into HARTs
> >
> > For an overview of the AIA specification, refer the recent AIA virtualization
> > talk at KVM Forum 2022:
> > https://static.sched.com/hosted_files/kvmforum2022/a1/AIA_Virtualization_in_KVM_RISCV_final.pdf
> > https://www.youtube.com/watch?v=r071dL8Z0yo
> >
> > This series adds required Linux irqchip drivers for AIA and it depends on
> > the recent "RISC-V IPI Improvements".
> > (Refer, https://lore.kernel.org/lkml/20221101143400.690000-1-apatel@xxxxxxxxxxxxxxxx/t/)
> >
> > To test this series, use QEMU v7.1 (or higher) and OpenSBI v1.1 (or higher).
> >
> > These patches can also be found in the riscv_aia_v1 branch at:
> > https://github.com/avpatel/linux.git
> >
> > Anup Patel (9):
> > RISC-V: Add AIA related CSR defines
> > RISC-V: Detect AIA CSRs from ISA string
> > irqchip/riscv-intc: Add support for RISC-V AIA
> > dt-bindings: Add RISC-V incoming MSI controller bindings
> > irqchip: Add RISC-V incoming MSI controller driver
> > dt-bindings: Add RISC-V advanced PLIC bindings
> > irqchip: Add RISC-V advanced PLIC driver
> > RISC-V: Select APLIC and IMSIC drivers for QEMU virt machine
> > MAINTAINERS: Add entry for RISC-V AIA drivers
> >
> > .../interrupt-controller/riscv,aplic.yaml | 136 ++
> > .../interrupt-controller/riscv,imsic.yaml | 174 +++
> > MAINTAINERS | 12 +
> > arch/riscv/Kconfig.socs | 2 +
> > arch/riscv/include/asm/csr.h | 92 ++
> > arch/riscv/include/asm/hwcap.h | 8 +
> > arch/riscv/kernel/cpu.c | 2 +
> > arch/riscv/kernel/cpufeature.c | 2 +
> > drivers/irqchip/Kconfig | 32 +-
> > drivers/irqchip/Makefile | 2 +
> > drivers/irqchip/irq-riscv-aplic.c | 656 +++++++++
> > drivers/irqchip/irq-riscv-imsic.c | 1207 +++++++++++++++++
> > drivers/irqchip/irq-riscv-intc.c | 37 +-
> > include/linux/irqchip/riscv-aplic.h | 117 ++
> > include/linux/irqchip/riscv-imsic.h | 92 ++
> > 15 files changed, 2564 insertions(+), 7 deletions(-)
> > create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
> > create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,imsic.yaml
> > create mode 100644 drivers/irqchip/irq-riscv-aplic.c
> > create mode 100644 drivers/irqchip/irq-riscv-imsic.c
> > create mode 100644 include/linux/irqchip/riscv-aplic.h
> > create mode 100644 include/linux/irqchip/riscv-imsic.h
> >
> > --
> > 2.34.1
> >
>
> I am seeing the following boot failure with your branch and upstream
> qemu (tag: v7.2.0-rc0).
> It seems IPIs are probably not getting delivered after a point. I saw
> that IPIs are delivered in the same path earlier (via gdb).
>
> [ 0.990152] NET: Registered PF_INET6 protocol family
> [ 1.004885] Segment Routing with IPv6
> [ 1.005385] In-situ OAM (IOAM) with IPv6
> [ 1.006371] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
> [ 1.011609] NET: Registered PF_PACKET protocol family
> [ 1.014877] 9pnet: Installing 9P2000 support
> [ 1.015603] Key type dns_resolver registered
> [ 1.026396] debug_vm_pgtable: [debug_vm_pgtable ]:
> Validating architecture page table helpers
> [ 1.144097] EXT4-fs (vda2): recovery complete
> [ 1.146345] EXT4-fs (vda2): mounted filesystem with ordered data
> mode. Quota mode: disabled.
> [ 1.147020] VFS: Mounted root (ext4 filesystem) on device 254:2.
> [ 1.152238] devtmpfs: mounted
> [ 1.183914] Freeing unused kernel image (initmem) memory: 2176K
> [ 1.185898] Run /sbin/init as init process
> [ 29.412287] rcu: INFO: rcu_sched self-detected stall on CPU
> [ 29.412992] rcu: 3-....: (5250 ticks this GP)
> idle=fc3c/1/0x4000000000000002 softirq=78/78 fqs=2230
> [ 29.413427] (t=5251 jiffies g=-1047 q=3 ncpus=8)
> [ 29.414199] CPU: 3 PID: 1 Comm: init Not tainted
> 6.1.0-rc4-00024-g5b711f2d7b91 #198
> [ 29.414578] Hardware name: riscv-virtio,qemu (DT)
> [ 29.414896] epc : smp_call_function_many_cond+0x138/0x372
> [ 29.415157] ra : smp_call_function_many_cond+0x154/0x372
> [ 29.415318] epc : ffffffff8008d2e6 ra : ffffffff8008d302 sp :
> ff2000000004bb40
> [ 29.415512] gp : ffffffff812e9eb0 tp : ff600000016d8000 t0 :
> ff6000007ed88610
> [ 29.415686] t1 : 00000000000000ff t2 : 0000000000000002 s0 :
> ff2000000004bc00
> [ 29.415837] s1 : ff6000007ed85448 a0 : 0000000000000007 a1 :
> 00000000000000f7
> [ 29.416008] a2 : 0000000000000000 a3 : 0000000000000000 a4 :
> ff6000007edd1780
> [ 29.416188] a5 : 0000000000000001 a6 : ffffffff812eb1c0 a7 :
> ff600000016d8000
> [ 29.416613] s2 : ffffffff81323c30 s3 : ffffffff812e9964 s4 :
> 0000000000000000
> [ 29.416810] s5 : 0000000000000000 s6 : ff6000007ed85440 s7 :
> 0000000000000038
> [ 29.416997] s8 : 0000000000000003 s9 : ffffffff81323c30 s10:
> ff6000007ed85448
> [ 29.417159] s11: 0000000000000008 t3 : 00ffffffad08a000 t4 :
> ff60000001613e0c
> [ 29.417331] t5 : 0000000000000000 t6 : 00ffffffad177fff
> [ 29.417482] status: 0000000200000120 badaddr: 0000000000000000
> cause: 8000000000000005
> [ 29.417939] [<ffffffff8008d590>] on_each_cpu_cond_mask+0x20/0x32
> [ 29.418179] [<ffffffff80008d32>] flush_icache_all+0x38/0x40
> [ 29.418324] [<ffffffff80008eb2>] flush_icache_pte+0x4a/0x7a
> [ 29.418442] [<ffffffff80139e00>] do_set_pte+0x132/0x192
> [ 29.418594] [<ffffffff8010b42e>] filemap_map_pages+0x178/0x3a0
> [ 29.418738] [<ffffffff8013ad00>] __handle_mm_fault+0x992/0xbac
> [ 29.418876] [<ffffffff8013afde>] handle_mm_fault+0xc4/0x1d4
> [ 29.419010] [<ffffffff80008372>] do_page_fault+0x120/0x326
> [ 29.419145] [<ffffffff800033e6>] ret_from_exception+0x0/0xc

This has been addressed in the RISC-V IPI improvement series.

Regards,
Anup

>
>
>
> --
> Regards,
> Atish