On Wed, Jul 27, 2022 at 5:23 AM Alistair Francis <alistai...@gmail.com>
wrote:
> On Sat, Jul 23, 2022 at 7:22 PM Atish Patra <ati...@rivosinc.com> wrote:
> >
> > Since commit 40244040a7ac, multi-socket configuration with plic is
> > broken as the hartid for second socket is calculated incorrectly.
> > The hartid stored in addr_config already includes the offset
> > for the base hartid for that socket. Adding it again would lead
> > to segfault while creating the plic device for the virt machine.
> > qdev_connect_gpio_out was also invoked with incorrect number of gpio
> > lines.
> >
> > Fixes: 40244040a7ac (hw/intc: sifive_plic: Avoid overflowing the
> addr_config buffer)
> >
> > Signed-off-by: Atish Patra <ati...@rivosinc.com>
> > ---
> > hw/intc/sifive_plic.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/intc/sifive_plic.c b/hw/intc/sifive_plic.c
> > index 56d60e9ac935..fdac028a521f 100644
> > --- a/hw/intc/sifive_plic.c
> > +++ b/hw/intc/sifive_plic.c
> > @@ -454,10 +454,10 @@ DeviceState *sifive_plic_create(hwaddr addr, char
> *hart_config,
> >
> > for (i = 0; i < plic->num_addrs; i++) {
> > int cpu_num = plic->addr_config[i].hartid;
> > - CPUState *cpu = qemu_get_cpu(hartid_base + cpu_num);
> > + CPUState *cpu = qemu_get_cpu(cpu_num);
> >
> > if (plic->addr_config[i].mode == PLICMode_M) {
> > - qdev_connect_gpio_out(dev, num_harts + cpu_num,
> > + qdev_connect_gpio_out(dev, cpu_num,
>
> Argh!
>
> I was trying to get this ready to go into 7.1. I have been working on
> updating my tests to catch this failure in the future as well.
>
> While testing this change I noticed that it breaks the noMMU test case.
>
> I think the correct fix is actually this (on top of your patch):
>
> diff --git a/hw/intc/sifive_plic.c b/hw/intc/sifive_plic.c
> index fdac028a52..af4ae3630e 100644
> --- a/hw/intc/sifive_plic.c
> +++ b/hw/intc/sifive_plic.c
> @@ -457,7 +457,7 @@ DeviceState *sifive_plic_create(hwaddr addr, char
> *hart_config,
> CPUState *cpu = qemu_get_cpu(cpu_num);
>
> if (plic->addr_config[i].mode == PLICMode_M) {
> - qdev_connect_gpio_out(dev, cpu_num,
> + qdev_connect_gpio_out(dev, num_harts - plic->hartid_base +
> cpu_num,
> qdev_get_gpio_in(DEVICE(cpu),
> IRQ_M_EXT));
> }
> if (plic->addr_config[i].mode == PLICMode_S) {
>
> The idea is that we need to increment the second argument to
> qdev_connect_gpio_out() for the PLICMode_M compared to the PLICMode_S
> case.
>
> This ensures that we do that correctly without breaking anything.
>
> How does that look to you?
>
>
Ahh yes. That makes sense.
Tested the updated change on multi-socket as well.
> Alistair
>
> > qdev_get_gpio_in(DEVICE(cpu),
> IRQ_M_EXT));
> > }
> > if (plic->addr_config[i].mode == PLICMode_S) {
> > --
> > 2.25.1
> >
> >
>
